VISUAL INSPECTION FOR AIRCRAFT.pdf

m U.S. Departmentof Transportation

Federal AviationAdministration

AdvisoryCircularAC NO.: 43-204DATE: 81 I4/97

VISUAL INSPECTION FOR AIRCRAFT

Initiated By: AFS-350

U.S. Departmentof Transportation

Federal AviationAdministration

Circular

Subject: VISUAL INSPECTION FOR Date 8/ 1 d/97AIRCRAFT Initiated by: AFS-350

AC No: 43-204Change:

1. PURPOSE. This advisory circular (AC) provides technical in-formation to persons conducting a visual inspection of aircraft.The procedures presented in this AC are an acceptable means, butnot the only acceptable means,and inspection programs.

for conducting visual inspectionsWhere the aircraft, engine, propeller,

or appliance manufacturer has published a recommended inspectionschedule or program for a particular aircraft, that programshould take precedence over the recommendations of this AC.

2. RELATED READING MATERIAL.

a. AC 20-37D, Aircraft Metal Propeller Maintenance.

b. AC 43-3, Nondestructive Testing in Aircraft.

C . AC 43-4A, Corrosion Control for Aircraft.

d. AC 43-7, Ultrasonic Testing for Aircraft.

e. AC 43-12A, Preventive Maintenance.

f. AC 43.13-lA, Acceptable Methods, Techniques andPractices--Aircraft Inspection and Repair.

Richard 0. GordonActing Deputy Director, Flight Standards Service

a/14/97 AC 43-204

CONTENTS

Parasraph Pase No.

-

CHAPTER 1. GENERAL 1

1. INTRODUCTION.2. RELATION OF VISUAL INSPECTION TO NONDESTRUCTIVE INSPECTION3. DEFINITION OF VISUAL INSPECTION.4. PURPOSE OF VISUAL INSPECTION.5. AIRFRAME AND ENGINE STRUCTURAL DETAILS.6. FACTORS AFFECTING VISUAL INSPECTION.7. SAFETY.8. THE VISUAL INSPECTION PROCESS.9. VISUAL INSPECTION, GENERAL.10. AIRFRAME VISUAL INSPECTION.11. ENGINE VISUAL INSPECTION.12. INSPECTION FOR SPECIFIC TYPES OF CORROSION.13.-199. RESERVED.

CHAPTER 2. VISUAL INSPECTION PROCEDURES

11122

1719192021242431

43

200. GENERAL. 43201. MATERIAL CONTAINED IN A VISUAL INSPECTION PROCEDURE. 43202. ACTIVITIES APPLYING TO ALL VISUAL INSPECTIONS. 44203. RECORD KEEPING. 45204. FOUR LEVELS OF VISUAL INSPECTION. 47205. ACCEPTABLE PRACTICE FOR VISUAL INSPECTION. 47206.-299. RESERVED. 52

CHAPTER 3. VISUAL INSPECTION AIDS

300. GENERAL.301. LIGHTING AND ILLUMINATION.302. LIGHTING SYSTEMS.303.-399. RESERVED.

63

6363

100104

CHAPTER 4. EQUIPMENT USED IN VISUAL INSPECTION

400. GENERAL.401. MAGNIFYING DEVICES.402. PHOTOGRAPHIC AND VIDEO SYSTEMS.403. OPTICAL COMPARATORS.404. BORESCOPES.405. LIST OF EQUIPMENT USED IN VISUAL INSPECTION.406.-499. RESERVED.

117

117120120126127156156

CHAPTER 5. DEFINITIONS

500. DEFINITIONS.501.-599. RESERVED.

167

167173

Page i

AC 43-204

APPENDIX A.

APPENDIX B.

APPENDIX C.

APPENDIX D.

APPENDIX E.

APPENDIX F.

APPENDIX G.

APPENDIX H.

FIGURE l-1.FIGURE 1-2.FIGURE 1-3.FIGURE 1-4.FIGURE l-5.FIGURE 1-6.

FIGURE 1-7.

FIGURE l-8.

FIGURE l-9.

8/14/97

BEACHCRAFT, ATA CODE 57-10, SAMPLE INSPECTIONPROCEDURE

BEACHCRAFT, ATA CODE 55-30, SAMPLE INSPECTIONPROCEDURE

PRATT & WHITNEY, ENGINE GENERAL--IhSPECTION/CHECK--00, SAMPLE INSPECTION PROCEDURE

PRATT & WHITNEY, ENGINE GENERAL--INSPECTION/CHECK--01A, SAMPLE INSPECTION PROCEDURE

DC-9 SERVICE BULLETIN, SAMPLE INSPECTION PROCEDURE

BOEING 747 SERVICE BULLETIN, SAMPLE INSPECTIONPROCEDURE

VISUAL INSPECTION EQUIPMENT

ENGINE VISUAL INSPECTION GLOSSARY

LIST OF ILLUSTRATIONS

Page No.

AREAS MOST SUSCEPTIBLE TO CRACKS 3TYPICAL SURFACE CRACKS 3MULTIPLE-SITE DAMAGE SURFACE FATIGUE CRACKS 4EXAMPLE OF SKIN-CRACKING AT FASTENERS 4AREAS MOST SUSCEPTIBLE TO CORROSION 5EXAMPLE OF MISSING RIVET HEADS RESULTING FROMCORROSION PRODUCTS 5EXAMPLE OF BLISTERING OF SEALANT IN A FUEL CELLCAUSED BY CORROSION 6EXAMPLE OF CHIPPED AND LOOSE PAINT ON A WING SKINCAUSED BY CORROSION 6INTERNAL CORROSION OF THE TUBULAR ENGINE MOUNT OFA 1946 VINTAGE CESSNA 7

FIGURE l-10. CORROSION OF THE RUDDER CONTROL CABLE OF A 1969CESSNA 172, FOUND VISUALLY 8

FIGURE l-11. CORROSION OF THE ELEVATOR RIB OF A 1969 CESSNA172, FOUND VISUALLY 9

FIGURE l-12. EXAMPLE OF SKIN-BULGING DUE TO CORROSION 9FIGURE l-13. EXAMPLE OF CRACKED NUT DUE TO CORROSION 10FIGURE l-14. LANDING GEAR AND WHEEL CORROSION POINTS 11FIGURE l-15.AREAS MOST SUSCEPTIBLE TO DISBONDING 12FIGURE l-16. COMMON PHYSICAL CHARACTERISTICS OF ENGINE

DEFECTS (3 SHEETS) 13FIGURE l-17. TYPICAL DEFECTS AS SEEN THROUGH BORESCOPE AND

OTHER AIDS 16FIGURE l-18. USING A FLASHLIGHT TO INSPECT FOR SURFACE

CRACKS 22

Page ii

FIGURE l-19.UNIFORM ETCH CORROSIONFIGURE l-20. PITTING CORROSIONFIGURE l-21.GALVANIC CORROSION OF MAGNESIUM ADJACENT TO

STEEL FASTENER

2627

FIGURE l-22. CONCENTRATION CELL CORROSIONFIGURE l-23. INTERGRANULAR CRACKING AND CORROSION ON A

WINGSPAR CHORD

2829

FIGURE l-24. SEVERE EXFOLIATION CORROSION

FIGURE- FIGURE

3031

FIGURE 3-l. EXAMPLE OF THE EFFECT OF SHINY AND MATTEFINISH OF PARTS AND LIGHTING SYSTEMORIENTATION ON SEEING TASKS 68

FIGURE 3-2. EXAMPLE OF THE EFFECT OF LIGHTING SYSTEMS ONINSPECTION OF A CIRCUIT BOARD 69

FIGURE 3-3. EXAMPLE OF THE EFFECT OF LIGHTING SYSTEMORIENTATION ON AN INSPECTION SURFACE 70

FIGURE 3-4. EXAMPLES OF DIRECT AND REFLECTED GLARE 75FIGURE 3-5. EXAMPLE OF LUMINAIRE SHIELDING ANGLE 77FIGURE 3-6. HARSH SHADOWS PRODUCED BY UNIDIRECTIONAL

ILLUMINATION (LEFT) AND SOFT SHADOWS PRODUCEDBY DIFFUSE ILLUMINATION 79

FIGURE 3-7. MULTIPLE SHADOWS (UPPER LEFT) ARE CONFUSING;SINGLE SHADOWY (CENTER) MAY CONFUSE, BUT CANHELP; DIFFUSED LIGHT (LOWER RIGHT) ERASES THESHADOWS 80

3-a. CORRELATED COLOR TEMPERATURE IN KELVINS OFSEVERAL ELECTRIC LIGHT AND DAYLIGHT SOURCES 82

3-9. INTERNATIONAL COMMISSION ON ILLUMINATIONLUMINAIRE CLASSIFICATIONS FOR GENERAL LIGHTING a3

FIGURE 3-10. TYPICAL LAMP AND FIXTURE LIGHT DISTRIBUTIONCURVES 84

FIGURE 3-11. ILLUSTRATION OF THE IMPORTANCE OF A WHITECEILING FOR IMPROVING THE VISUAL ENVIRONMENTOF AN INDUSTRIAL FACILITY 85

FIGURE 3-12 EXAMPLES OF PLACEMENT OF SUPPLEMENTARYLUMINAIRES 07

FIGURE 4-l. TYPICAL 35MM CAMERA AND CAMERA ADAPTERINSTALLATION ON A RIGID BORESCOPE 121

FIGURE 4-2. TYPICAL BORESCOPE VIDEO ADAPTER SYSTEM 122FIGURE 4-3. BLOCK DIAGRAM OF A TYPICAL VIDEO INSPECTION

SYSTEM 123FIGURE 4-4. SCOPEMAN HAND-HELD VIDEO MICROSCOPE IMAGING

SYSTEM 124FIGURE 4-5. SMARTSCOPE VIDEO MEASURING MICROSCOPE SYSTEM 125FIGURE 4-6. SCHEMATIC OF AN OPTICAL COMPARATOR 126FIGURE 4-7. TYPICAL OPTICAL COMPARATOR 127FIGURE 4-8. THREE TYPICAL DESIGNS OF BORESCOPES 128FIGURE 4-9. TYPICAL DIRECTIONS AND FIELD OF VIEW OF RIGID

BORESCOPES 129133134135

FIGURE 4-10. TYPICAL MICRO-BORESCOPEFIGURE 4-11. TYPICAL EXTENDIBLE BORESCOPEFIGURE 4-12. TYPICAL SCANNING BORESCOPE

- FIGURE 4-13. ZOOM-A-BORE INSPECTION INSTRUMENT WITHMAGNIFICATION BOOSTER ATTACHED 136

a/14/97 AC 43-204

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fit 43-204 a/14/97

FIGURE 4-14. MICRO-BORE VIEWING SYSTEMFIGURE 4-15. MIRROR TUBE VIEWING SYSTEMFIGURE 4-16. DEEP-HOLE MIRROR VIEWING SYSTEMFIGURE 4-17. TYPICAL FLAWS SEEN THROUGH A FLEXIBLE

FIGURE 4-18. COMPARISON VIEWS WITH DIFFERENT QUANTITIES

FIGUREFIGUREFIGURE

FIGURE 4-22. VIEW THROUGH A MEASURING FIBERSCOPEFIGURE 4-23. RETRIEVAL DEVICE IN BORESCOPE WORKING CHANNELFIGURE 4-24. FLYING PROBE FLEXIBLE BORESCOPEFIGURE 4-25. VIDEOHOOK PROBE ATTACHMENT FOR A FLEXIBLE

FIGURE 4-26. POWER BLENDING BORESCOPE KITFIGURE 4-27. SHADOWPROBETM MEASURING SYSTEM

FIBERSCOPE

OF FIBERS IN THE FIBERSCOPE IMAGE BUNDLE4-19. FLEXIBLE VIDEOSCOPE IMAGES4-20. TYPICAL CCD VIDEOSCOPE RESOLUTION4-21. COMPARISON BETWEEN VIDEOSCOPE AND FIBERSCOPE

IMAGES

BORESCOPE

TABLE 1-l.TABLE 2-l.

TABLE 3-1.TABLE 3-2.

TABLE 3-3.

TABLE 3-4.

TABLE 3-5.

TABLE 3-6.

TABLE 3-7.

TABLE 3-8.TABLE 4-l.TABLE 4-2.TABLE 4-3.

137139140

141

143144145

146147148151

152153154

LIST OF TABLES

Paqe No.

ILLUMINANCE LEVELS FOR SAFETY*TOPICS TO BE CONSIDERED IN PREPARING OR REVIEWINGA VISUAL INSPECTION PROCEDUREILLUMINANCE VALUESWEIGHTING FACTORS TO BE CONSIDERED IN SELECTINGSPECIFIC ILLUMINANCE WITHIN RANGES OF VALUESFOR EACH ILLUMINANCE CATEGORYIES RECOMMENDED ILLUMINANCE CATEGORIES FOR THEDESIGN AND EVALUATION OF LIGHTING SYSTEMS FORINDUSTRIAL INSPECTION AREASCLASSIFICATION OF VISUAL TASKS AND SUPPLEMENTARYLIGHTING TECHNIQUES (3 SHEETS)RECOMMENDED REFLECTANCE VALUES FOR INDUSTRIALLIGHTINGRECOMMENDED MAXIMUM LUMINANCE RATIOS FORINDUSTRIAL LIGHTINGTYPICAL PORTABLE LUMINAIRES FOR SUPPLEMENTARYLIGHTING (7 SHEETS)TYPICAL INSPECTION FLASHLIGHTS (5 SHEETS)TYPICAL INSPECTION MIRRORSTYPICAL SIMPLE MAGNIFIERSTYPICAL WORKING CHANNEL DEVICES

18

4465

66

67

71

78

81

8996

117119149

Page iv

8/14/97

CHAPTER 1. GENERAL

AC 43-204

1. INTRODUCTION. Over 80 percent of the inspectipns on largetransport category aircraft are visual inspections. On smalltransport aircraft the ratio is even greater and on general avia-tion aircraft, virtually all inspection is visual. Visual in-spection is usually the most economical and fastest way to obtainan early assessment of the condition of an aircraft and its com-ponents. Most of the defects found on aircraft are found by vis-ual inspections, and the airframe manufacturers and users dependon regular visual inspections to ensure the continued airworthi-ness of their aircraft. Consequently, it is important that vis-ual inspection methods be understood and properly applied bythose responsible for the continued airworthiness of aircraft.Proficiency in visual inspection is crucial to the safe operationof aircraft. Such proficiency is gotten from experience, butalso by learning the methods developed by others. This documentdescribes those methods and the way they are used in the variousinspections carried out on aircraft.

2. RELATION OF VISUAL INSPECTION TO NONDESTRUCTIVE INSPECTION (NDI).Visual inspection is an essential part of airplane maintenance.The visual inspection component of ND1 requires trained and expe-rienced inspection personnel, using validated procedures and ap-propriate calibration standards with effective, well-maintainedequipment in a well-managed maintenance environment.

3. DEFINITION OF VISUAL INSPECTION. Visual inspection is de-fined as the process of using the eye, alone or in conjunctionwith various aids, as the sensing mechanism from which judgmentsmay be made about the condition of a unit to be inspected. Imag-ing devices are playing an increasing part in the inspectionprocess, (e.g., ultrasonic C-scans, eddy current imaging, real-time X ray). Analysis of such displays is not considered visualinspection and will be covered under image analysis in AC 43-X,Nondestructive Inspection For Aircraft.

1 Goranson, U.F. and Rogers, J.T., "Elements of Damage Tol-erance Verification," 12th Symposium of International CommercialAeronautical Fatigue, Touluse, France, May 1983.

Chap 1Par 1 Page 1

t'ic 43-204

4. PURPOSE OF VISUAL INSPECTION.

a/14/97

Visual

l

l

inspection is used to:

Provide an overall assessment of the condition of a struc-ture, component, or system.

Provide early detection of defects before they reachcritical size.

0 Detect errors in the manufacturing process.

l Obtain more information about the condition of a componentshowing evidence of a defect.

In many situations, no reliable alternative exists to visual in-spection. Visual procedures are mandated by the FAA for struc-tural inspections to support Supplementary Structural InspectionDocuments (SSIDs), Service Bulletins (SBs), and Airworthiness Di-rectives (ADS).

5. AIRFRAME AND ENGINE STRUCTURAL DETAILS.

a. Tvpical Airframe Defects. Typical airframe defects foundin aircraft which can be detected by visual inspection can be di-vided into three types: cracks, corrosion, and disbonding. Otherdefects, such as system and component wear, accidental damage,environmental damage from long term storage, sunlight, etc., canalso be detected visually.

tible to c~~~ksCracks'Figure l-1 illustrates areas most suscep-

Figure 1-2 shows typical surface cracks whichcan be detected by visual inspection. Surface cracks caused byfatigue are illustrated in Figure l-3. An example of skin-cracking at fasteners is shown in Figure l-4. Sometimes an un-derlying crack can cause a distortion which can be detected visu-ally.

Page 2Chap 1Par 4

8/14/97 AC 43-204

Empennage General Condition:Attach Pointe

Engine MountAttach Points

Skin Doublers and Pressure

J T\ A i r c r a f tBulkheads On Pressurized

@?+?A Fuel Tanks

Wing Spars and CapsLower Wing Skins

FIGURE l-1. AREAS MOST SUSCEPTIBLE TO CRACKS

1 4

FIGURE 1-2. TYPICAL SURFACE CRACKS

Chap 1Par 5 Page 3

Ar:43-204 8/14/97

FIGURE 1-3. MULTIPLE-SITE DAMAGE SURFACE FATIGUE CRACKS

. . .PI’.-’

FIGURE 1-4. EXAMPLE OF SKIN-CRACKING AT FASTENERS

(2) Corrosion . Figure 1-5 illustrates areas most sus-ceptible to corrosion. The various manifestations of corrosionsuch as missing rivet heads are shown in Figure l-6.

Page 4Chap 1Par 5

e/:14/97

Passenger Floor SupportsCargo and and FlooringCrew Doors I

Under De-IcerGalley Areas/

Path ofGasses

Areas

La&0ryAreas

UndercarriageBays

Integral Fuel Tanks

FIGURE 1-5. AREAS MOST SUSCEPTIBLE TO CORROSION

FIGURE 1-6. EXAMPLE OF MISSING RIVET HEADS RESULTINGFROM CORROSION PRODUCTS

An example of blistering of paint in a fuel cell caused by corro-sion is illustrated in Figure 1-7. Chipped and loose paint on a

Chap 1Par 5 Page 5

Al: 43 -- ?. 0 4 g/14/97

wing skin is shown in Figure 1-8. Figure 1-9 shows internal cor-rosion of a tubular engine mount.

FIGURE l-7. EXAMPLE OF BLISTERING OF SEALANT IN A FUEL CELLCAUSED BY CORROSION

FIGURE 1-8. EXAMPLE OF CHIPPED AND LOOSE PAINT ON A WINGSKIN CAUSED BY CORROSION

Page 6Chap 1Par 5

a/-l A/97

FIGURE l-9. INTERNAL CORROSION OF THE TUBULAR ENGINE MOUNTOF A 1946 VINTAGE CESSNA(Courtesy of Shoreline Aviation, MarshfieldMunicipal Airport, MA)

Chap 1Par 5 Page 7

AC 43-204 8/14/97

Corrosion of a rudder control cable and elevator rib are shown inFigures l-10 and l-11, respectively. Figure l-12 shows an exam-ple of skin-bulging from corrosion of the faying surface betweenskin and internal structure around a cargo doorway. Figure l-13shows two examples of a nut which cracked from corrosion fatigue.Figure l-14 illustrates landing gear and wheel corrosion points.

FIGURE l-10. CORROSION OF THE RUDDER CONTROL CABLE OF A1969 CESSNA 172, FOUND VISUALLY(Courtesy of Shoreline Aviation, MarshfieldMunicipal Airport, MA)

Page 8Chap 1Par 5

8/14/97 AC 43-204

FIGURE l-11. CORROSION OF THE ELEVATOR RIB OF A 1969 CESSNA 172,FOUND VISUALLY (Courtesy of Shoreline Aviation,Marshfield Municipal Airport, MA)

FIGURE 1-12. EXAMPLE OF SKIN-BULGING DUE TO CORROSION

Chap 1Par 5 Page 9

Ar, 43-204 8/14/97

FIGURE l- 13. EXAMPLE OF CRACKED ?XJT DUE TO CORROSION(Courtesy of McDonnell Douglas)

Page 10Chap 1Par 5

8/14/97 AC 43-204

TYPICAL DEBRIS TIUH)

UNPLATED HIGHSTRENGTH STEELINSIDE ULES

DISSIMILAR METAL

UNDER FERRULES ANDIDENTI~~ATION TAPES

WHEEL BEARING RACES

FIGURE 1-14. LANDING GEAR(Courtesy of

AND WHEEL CORROSION POINTSthe U.S. Navy)

(3) m. It is very difficult to detect dis-bonding by visual means, since it is usually an internal condi-tion and not likely to show up on the surface of an aircraft.Figure l-15 illustrates areas most susceptible to disbonding.Wherever a bonded surface becomes disbonded, corrosion is likelyto occur and may be detected visually.

Chap 1Par 5 Page 11

A: 43-204 S/14/97

,

Multiple ElementWing Spar Assemblies

Skin Doublers

Doors

FIGURE 1-15. AREAS MOST SUSCEPTIBLE TO DISBONDING

b. Enoine Defects. Figure l-16 shows typical defects foundduring inspection of engine components. Frequently it is neces-sary to use visual aids to detect defects. Figure l-17 illus-trates typical defects seen through borescopes and other aids.

Page 12Chap 1Par 5

AC: 43-204

.

FIGURE l-16. COMMON PHYSICAL CHARACTERISTICS OF ENGINE DEFECTS(Sheet 1 of 3)(Courtesy of Pratt & Whitney)

Chap 1Par 5 Page 13

BLISTEFING

A': 43-204

P 618k

BURNING CHIPPING

+ 8565:

CRACK

BURNING

CORROSION

EROSION

FIGURE l-16. COMMON PHYSICAL CHARACTERISTICS OF ENGINE DEFECTS(Sheet 2 of 3)

Page 14 Chap 1Par 5

FRACTURE FRETTING,’ “,? r::

0s Ior

P.942lM

GOUGING

GALLJII~G

FIGURE l-16. COMMON PHYSICAL CHARACTERISTICS OF ENGINE DEFECTS(Sheet 3 of 3)

Chap 1Par 5 Page 15

43-204 8/14/97

FIGURE l-17. TYPICAL DEFECTS AS SEEN THROUGH BORESCOPE ANDOTHER AIDS(Courtesy of McDonnell Douglas)

Page 16Chap 1Par 5

a/14/97 AC 43-204

6. FACTORS AFFECTING VISUAL INSPECTION. Any factor that aidsvisual effectiveness increases the probability of detecting thepotential cause of a failure and subsequent corrective action.

a. Inspection Personnel Oualifications and Traininq. In-spection personnel should posses experience and knowledge of theorigins and causes of defects in raw material manufacturing proc-esses, the reshaping and redistribution of these defects in sub-sequent part manufacturing processes, and defects that developafter the part is put in service. Inspection personnel shouldalso have a working knowledge of the part, component, or aircraftbeing inspected. It is essential that inspection personnel beknowledgeable concerning the structural detail being evaluated toenable them to properly locate, identify, and evaluate aircraftdefects. Persons who inspect, approve, and return to service anaircraft appliance or part, must be certified in accordance withthe appropriate FARs or perform the work under a certificateholder who is directly in charge of that person.

b. Insoection Area Access. Ease of access to the inspectionarea is important in obtaining reliable visual inspection re-sults. Access consists of the act of getting into an inspectionposition (primary access) and performing the visual inspection(secondary access). Unusual positions (i.e., crouching, lying onback, and overhead reaching) constitute examples of difficult ac-cess.

(1) Imr3act on Inspection. The necessity to get bothhands into the aircraft structure while holding a flashlight ormirror or reaching into awkward openings can affect the inspec-tor's motivation, attitude, decision-making, and ability to in-terpret what is seen.

(2) Access and Safety. Staging equipment (e.g., plat-forms, ladders, stools) used to permit access to the airframe andengines should be used safely, i.e., secured manually or brakeengaged to prevent slips and falls. Protection should be pro-vided to prevent potential injury from sharp edges and shifts inheavy weights. Adequate protection from falls should be providedwherever possible, such as railings and harnesses and lanyards onhigh working platforms.

C . Lishtinq. Adequate quality and intensity of illuminanceand elimination of direct glare, reflected glare, and harsh shad-ows all enhance the identification of defects. Conversely, ex-cessive visual fatigue and the delayed eye adaptation experiencedwhen moving from bright surroundings into dark ones and viceversa could reduce effective detection of defects.

(1) Localized Illumination. Illumination should be pro-vided during occupancy of spaces that possess limited access. In

Chap 1Par 6 Page 17

AC43-204 a/14/97

those areas which do not have fixed lighting, portable and vehi-cle-mounted lighting equipment should be used.

(2) Excessive Glare. Uncontrolled large differences ofillumination and excessive glare should be avoided. Appropriateguides to limiting glare and adaptation effects are discussed inChapter 3 of this AC and in the Illumination Engineering Society(IES) handbooks on lighting.

Page 18

(3) Lishtins and Safety. Some accidents which have beenattributed to an individual's carelessness could have been par-tially due to poor lighting. Illumination levels regarded as ab-solute minimums for safety alone have been developed by the IESand are listed in Table l-l.

TABLE l-l. ILLUMINANCE LEVELS FOR SAFETY*

HAZARDS REQUIRING VISUAL SLIGHT HIGHDETECTION

Normal** Activity Level Low High Low High

Illuminance Levels 0.5 1 2 5(Footcandles)

t M i n i m u m illuminance f o r safety o f pc?oplc, a b s o l u t e minlmum a t a n y tlmc a n d a ta n y location o n a n y p l a n e whrre safet.y IS rcxlated t o sreinq condlions.

l * S p e c i a l c o n d i t i o n s m a y require dlffcrent lllumlnance l e v e l s . I n s o m e c a s e shiqher l e v e l s m a y b e r e q u i r e d , a s f o r e x a m p l e w h e r e security i s a f a c t o r . I n s o m ec a s e s g r e a t l y r e d u c e d l e v e l s , includinq t o t a l ddrkncss, m a y br n e c e s s a r y , s p e c i f i -c a l l y i n sltuatlons i n v o l v i n g manufacturlnq, h a n d l i n q , u s e , o r processinq o fllqht-sensitive m a t e r i a l s ( n o t a b l y In conncctlon with photoqraphlc p r o d u c t s ) . I nt h e s e sltuatlons a l t ernatc m e t h o d s o f ~nsur~nq :;afr operations s h o u l d b e reliedupon .

NOTE: See specific application reports of the IESfor guidelines to minimum illuminances for safety byarea.

d. Precleaning. It is necessary for parts to be inspectedto be free from dirt, contamination, or anything which would tendto obscure detection of important defects. It is also importantduring cleaning not to remove or obscure evidence of a defect.For example, cracks may become hidden by abrasive treatment andrendered invisible.

e. Workinq Environment Factors. Excessive temperature,wind, rain, and other climactic factors tend to adversely affectinspections. Excessive noise tends to reduce concentration, cre-ate tension, and prevent effective communication. These condi-tions increase the likelihood of errors, degrade reliability, andpotentially impact personnel safety. The FAA's human factors re-

Chap 1Par 6

8/14/97 AC 43-204

search program addresses yany factors which affect the reliabil-ity of visual inspection.

7. SAFETY.

a. General. Safety hazards which could cause injuryto the inspector or prevent the identification of defects shouldbe eliminated or minimized.

b. Safety Instructions for Inspection Svstems and Materials.The operating safety instructions of the manufacturers of the in-spection systems and materials should be followed. The eye canbe harmed by intense lighting and lasers (which have their ownassociated safety regulations and precautions). The various ma-terials used for cleaning in preparation for visual inspectionmay contain chemicals which, if improperly used, can be hazardousto the health and safety of operators. Safe handling of cleaningmaterials is governed by the suppliers' Material Safety DataSheets (MSDSs) . MSDSs, conforming to 29 CFR 1910.1200, orequivalent, should be provided by the supplier to any user andshould be prepared in accordance with FED-STD-313. Flammable orcombustible cleaners and chemicals should be kept in approvedsafety containers and only in minimum quantities. Some cleanersand chemicals may have an adverse effect on skin, eyes, and res-piratory tract. Manufacturers' warning labels and current safetydirectives should be observed. Cleaners and chemicals should beused only in authorized areas. Soiled flammable or combustiblecloths should be discarded into covered metal containers.

8. THE VISUAL INSPECTION PROCESS. The process of visual inspec-tion should contain two fundamental elements to be successful:(1) a trained inspector with binocular vision and good visualacuity; (2) an inspection procedure which defines the details ofthe inspection, including examples of the defect(s) tracked.This document presents examples of these elements and their in-terrelation in aircraft inspection. The findings of qualifiedinspectors using appropriate procedures on specific details of anaircraft can be analyzed to provide quantitative data on the re-liability of inspection for a given detail. Knowledge gainedfrom this analysis establishes the time intervals at which theinspections are performed.

a. Procedures and Processes for Visual Inspection. Thevarious components of a modern aircraft vary depending upon theiruse, material makeup, method of fabrication, and the environmentin which they operate. While most of the aids for the inspection

2 Office of Aviation Medicine Reports: Human Factors Issues inMaintenance and Inspection, 1994.

Chap 1Par 6 Page 19

AC 43-204 8/14/97

process are used for engines, airframes, related systems, compo-nents, and accessories, they are used to a differing degree andmay be modified and configured for specific applications. Themajor difference between inspection of engines and airframes isthat only cursory inspections of engines can be made on the air-craft. Although borescopes and other enhancements are expandingthe number and quality of inspections on mounted engines, com-plete and rigorous engine inspections necessitate their removalfrom the aircraft and, in many cases, full teardown.

b. Generalized Techniaues. Successful visual inspections onany type of structure usually embody known techniques and proce-dures which have been developed by experience. Examples of suchtechniques are described in Section 9.

C . Specific Techniaues. There are specific techniques fordetecting defects unique to airframes and engines. Specificguidelines and techniques used for inspection of airframes andengines are described in Sections 10 and 11, respectively.

9. VISUAL INSPECTION, GENERAL. To conduct an effective visualobservation, inspection personnel should not only look at an ob-ject, but examine it based on their knowledge of it and estab-lished rules.

a. Tarsets. Effective inspectors look at specific targetsrather than scan an area. The eye is functionally blind when itis moving between observation points. Accordingly, a procedureof step-scanning is used. Lookouts spotting objects on the hori-zon are taught to step-scan with binoculars. Those who are pro-ficient can detect approaching objects long before they are oth-erwise visible. Similarly, when observing dim objects against adark background, observers are taught to focus to one side orabove the object viewed. They are then able to see details whichare not otherwise visible. These and other types of methods canbe used by inspectors to look for target defects in all parts ofthe aircraft.

b. Imasination. Another useful technique for the inspectoris to imagine what type of action would cause a particular de-fect. This thought process may provide a clue as to what the de-fect will look like. Skin wrinkles, which may be caused by anunderlying crack, are an example of a defect identified by such aprocess.

C . Markinss. Markings or anomalous concentrations of dis-coloration may signal the presence of a defect. When smoking waspermitted on aircraft, inspectors knew that nicotine smears wereassociated with skin cracks. Close inspection is still necessarywhere concentrations of contaminants and discoloration occur,since they may signal the existence of crack sites. Scratches,marks, and other anomalous features on the area inspected inform

Page 20Chap 1Par 8

8/14/97 AC 43-204

the trained inspector and are used to detect defects which mayaffect airworthiness. Loose rivets tend to emit “smoke", discol-oration, and streaking (localized).

d. Corrosion. Corrosion is primarily detected by visual in-spection. Since its detection is critical, inspection personnelshould be familiar with the appearance of the common types ofcorrosion and have training and experience in corrosion detectionon aircraft structural and engine materials. Corrosion Controlfor Aircraft (AC 43-4A) contains technical information on corro-sion identification, photos illustrating examples of typical cor-rosion, and guidance on treatment of corrosion on aircraft struc-tural, engine, and related materials. It may be necessary to re-move corrosion to assess the condition of the underlying mate-rial. It is important not to destroy the surface finish, or re-move protective coatings which would be difficult to replace,such as the “cladding" found on the skin surface of major trans-ports. In general aviation, an inspector will sometimes probe apart with a center punch in an area of suspected corrosion; ifmore than a minor indentation is observed, corrosion is present.

e . Inspection After Maintenance. After a component has beenserviced, repaired, or otherwise maintained, it should be in-spected for abnormalities. A similar inspection of the surround-ings should be carried out when a component or accessory is rein-stalled in the aircraft. Look for loose material, missing coat-ings, other damage, etc.

10. AIRFRAME VISUAL INSPECTION. It is necessary not only to knowhow to examine, but where to examine, when inspecting details fordefects with which one is familiar from past inspections. Theflashlight and the mirror are standard tools which should accom-pany the inspector on all inspections. The inspector should be-come skillful in using these tools. Also, magnifiers should bereadily at hand for some types of inspections. Other aids whichmay be available for specialized requirements are described inChapters 3 and 4. The flashlight/mirror combination can be usedto illuminate an area as well as view it and is particularlyvaluable in inaccessible spots. Magnifiers are invaluable fordefining the extent and character of cracks and problems in riv-eted assemblies.

a. Visual Detection of Surface Cracks. When searching forsurface cracks with a flashlight, the light should be directed ata 5- to 45-degree angle (see Figure l-18). The light beam shouldnot be directed at such an angle that the reflected light beamshines directly into the eyes. The eyes should be focused abovethe beam during the inspection. The extent of any cracks can bedetermined by directing the light beam at right angles to thecrack and tracing its length. A lo-power magnifying glass shouldbe used to confirm the existence of a suspected crack. If this

Chap 1Par 9 Page 21

AC 43-204 8/14/97

is not adequate, other ND1 techniques-such as penetrant, magneticparticle, or eddy current-may be used to verify cracks.

INCIDENT _LIGHT BEAM

EYE ABOVEREFLECTED

FA\ilNG CRACK OPENSURFACES TO SURFACE

FIGURE l-18. USING A FLASHLIGHT TO INSPECT FOR SURFACE CRACKS

b. Visual Detection of Hidden Defects. The mirror can beused with great effect in locations that cannot be viewed di-rectly. The mirror is frequently attached to a long arm so thatit can be directed around corners. It is frequently necessary toshine a light onto the mirror and indirectly illuminate the arearequiring or undergoing inspection.

c. Hardware and Fasteners. Rivets, bolts, and other miscel-laneous structural hardware should be inspected for looseness,integrity, proper size and fit, and corrosion. Dished, cracked,or missing rivet heads and loose rivets should be identified andrecorded, using the arsenal of visual inspection techniquesavailable. The inspector should ensure that sufficient light isavailable to be able to really see every fastener. Once again, aflashlight is indispensable.

d. Control Systems. Cables, control rods, rod ends, fair-leads, pulleys, and all other similar items should be examinedfor integrity, structural soundness, and corrosion.

e. Visual Insoection for Corrosion. Inspection of an air-craft for corrosion follows a systematic pattern.

(1) Clues. The aircraft is initially observed for cluesas to the care with which it has been maintained. Have obvious

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8/14/97 AC 4 3 - 2 0 4

corrosion control measures been taken ? Have drains been cleaned,paint replaced, and debris removed?

(2) Locations. Inspect likely corrosion sites. Theseinclude galleys and food service areas, lavatories, bilges, tankdrains, and fastenings. When debris is found, it should be exam-ined for iron oxide and the characteristically white powdery alu-minum hydride. Biological contamination (mold, algae), which mayfeel greasy or slippery, frequently causes corrosion since it al-ters the acidity of any moisture it contains. Caulking and seal-ing compounds should be tested for sound adhesion since corrosioncan intrude under such materials. Nutplates should be investi-gated for underlying corrosion. Tap tests should be performedfrequently and any dull sounding areas investigated carefully.The use of a center punch or awl to indent a surface should beused with care, since awl or center punch pricks can serve assites for the initiation of fatigue cracks. The omission of fueladditives by some fuel vendors can accelerate the deteriorationof tankage on small aircraft. In such cases, it is necessary todrain tanks and inspect them using lighted borescopes or otheraids. Flight and control surfaces are difficult to inspect sinceaccess is difficult. Extensive use of aids is recommended forsuch locations.

(3) Sites. Careful detailed examination of corrosionsites is then accomplished to define the extent of corrosion.This can lead to removal of skin panels or other measures to fur-ther define the extent of damage.

f. Disbonds. Many aircraft have extensive regions of adhe-sive bonding of the structure alone or in combination with riv-ets. It is frequently necessary to detect disbonds and adhesivefailure in structure. It should be remembered that, in adhe-sively bonded structures, evidence of corrosion frequently sig-nals the loss of bond integrity. A good example of this condi-tion is the pillowing which appears behind rivets. If the struc-ture is bonded as well as riveted, one can be sure that wherepillowing exists the bond is destroyed. Unfortunately, the re-verse is not also true. It is quite possible for an uncorrodedjoint to be disbonded. Frequently, the only means for detectingsuch a disbond is to mechanically distort the structure and de-termine whether any adhesion exists in the area of interest.Specifically, the waffle doublers, which act as tear preventersin pressurized aircraft, should be tested where possible.

g. Painted Surfaces. Painted surfaces should be inspectedfor chipped, missing, loose or blistered paint and for evidenceof corrosion. Refer to AC 43-4A for examples of corrosion.

h. Windshields and Ports. Transparent surfaces-such aswindshields, windows, and ports-should be inspected for cracks,crazing, and seeds using a Larascope or similar device. This de-

Chap 1Par 10 Page 23

AC 43-204 8/14/97

vice uses a plastic prism to permit viewing the interior oftransparent plastic or glass window material. The prism is opti-cally coupled to the window being inspected by use of an oilcouplant, enabling the operator to see inside the glass. Theprism can be manipulated to observe if any cracks are emanatingfrom drill holes or from edges of the transparent material.

i. Other Surface Discontinuities. Other surface disconti-nuities-such as discoloration from overheating; buckled, bulging,or dented skin; cracked, chafed, split, or dented tubing; chafedelectrical wiring; delaminations of composites; and damaged pro-tective finishes-may be found by careful visual inspection.

11. ENGINE VISUAL INSPECTION. Some superficial clues to enginecondition are leaks and evidence of smoke. Details observed inengine inspection which differ from airframe inspection generallyrelate to surface finish and the means for inferring underlyingconditions.

a. Forqinqs, Weldments, Castinqs, and Machined Parts. Thesurface texture of the components differs from that of the rolledand formed surfaces most common in airframes. The components aretherefore inspected using different criteria. So many engine de-fects are related to surface features of the material that aglossary of terms is used in most engine manuals to describevisible surface characteristics in terms of the process whichcaused them and its effect on satisfactory performance of thepart. As a result, much of the current guidance relating to en-gine visual inspection is related to manufacturing processes.This document covers only those visual inspection issues relatingto operational and maintenance inspection. The Engine Visual In-spection Glossary in this document, however, describes defectswhich may be found by maintenance inspectors in the field, butare more often found in the manufacturing process rather than"in-service" operations or maintenance.

b. Encrine Environment. Another difference related to engineinspection is associated with the environment in which enginesare expected to operate. Many engine parts are expected to sur-vive in intense heat. Inspections within the protective enclo-sures surrounding these areas often require complex visual aidssuch as light pipes, borescopes, and special inspection fixtur-ing.

12. INSPECTION FOR SPECIFIC TYPES OF CORROSION. This sectionprovides general information for visual inspection of aircraftstructure and components for specific types of corrosion. Visualinspection is the primary method for inspecting aircraft struc-ture and components for corrosion. Other ND1 techniques such aseddy current, ultrasonic, radiographic, magnetic particle, andpenetrant inspection are also used to supplement visual inspec-tion. These other ND1 techniques are generally used when costly

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disassembly would be required to gain access to hidden structureor components to accomplish visual inspections. They are alsoused to measure or estimate material loss due to corrosion and toverify the effectiveness of corrosion removal. Inspection ofaircraft for corrosion is a continuing requirement and should bedone on a daily basis.

a. Corrosion. Corrosion is the electrochemical deteriora-tion of a metal because of its reaction with the surrounding en-vironment. While new and better materials are continuously beingdeveloped, this progress is offset, in part, by a more aggressiveoperational environment. Corrosion is a complex phenomenon whichcan take many different forms and the resistance of aircraft ma-terials to corrosion can drastically change with only a small en-vironmental change.

b. Catastrophic Corrosion Events. Corrosion is most oftenthought of as a slow process of material deterioration, takingplace over a significant period of time (examples being generalcorrosion, pitting, exfoliation, etc.). Other forms of corrosiondegradation can occur very quickly, in days or even hours, withcatastrophic results. These forms (such as stress corrosioncracking, environmental embrittlement, and corrosion fatigue) de-pend on both the chemical and mechanical aspects of the environ-ment and can cause catastrophic structural failure without warn-ing.

C . Corrosion Occurrence. Corrosion occurs on almost allmetals; however, the use of corrosion resistant metals and theapplication of protective coatings minimize aircraft corrosion.Many other factors contribute to the amount and degree of air-craft corrosion such as the operational environment, materialsused in the original design, and the amount of operational pres-ervation provided during maintenance and repair.

d. Aircraft Environment. Aircraft exposed to salt air,heavy industrial pollution, and/or over water operations will ex-perience more corrosion problems than aircraft operated in a dryenvironment. Corrosion is caused by the presence of salts inmoist air or by some other abatement to corrosion present in thechemical content of the water or elements in the metal.

e. Manufacturers' Handbooks. Manufacturers' handbooksshould be used as a general guide when an area is to be inspectedfor corrosion. Some manufacturers have developed videos explain-ing the process of corrosion and separate corrosion control manu-als that are the basis for a complete aircraft corrosion inspec-tion and program. On aircraft for which the manufacturer has notpublished a recommended corrosion inspection schedule and treat-ment program, the recommendations of Advisory Circular (AC)43-4A, Corrosion Control for Aircraft, should be followed.


AC 43-204 8/14/97

f. urrn Etch Corrosion. Uniform etch corrosion resultsfrom a relatively uniform chemical attack on a metal surface (seeFigure l-19). On a polished surface, this type of corrosion isfirst seen as a general dulling of the surface, and if the attackis allowed to continue,frosted in appearance.

the surface becomes rough and possibly

FIGURE l-19.UNIFORM ETCH CORROSION(Courtesy of Thomas Flournoy)

Page 26Chap 1Par 12

8/14/97 AC 43-204. Ilttlna Corrosion The most common form of corrosion onand magnesium alloys is pitting (see Figure l-20). It

is first noticeable as a white or gray powdery deposit, which,when removed reveals uneven corrosive attack which is revealed aspits or holes in the surface.

FIGURE l-20. PITTING CORROSION

h. Galvanic Corrosion. Galvanic corrosion occurs when twodissimilar metals make electrical contact in the presence of anelectrolyte (see Figure l-21). The electromotive force (EMF) se-ries lists metals in the order of their ability to corrode asfollows.

1. Magnesium Alloys2. Zinc (plate)3. Beryllium4. Cadmium (plate)5. Aluminum Alloys*6. Tin (plate)7. Copper (plate)8. Nickel (plate)9. Chromium (plate)10. Brass (yellow or11. Bronze

12. Copper13. Monel14. Stainless Steels15. Titanium Alloys16. Silver17. Palladium18. Gold19. Rhodium20. Platinum

naval) 21. Carbon/Graphite

. 2024 (copper ailoysl used mostly III fuselages and the 7000 (zinc alloy) series usedmostly in flying and control surfaces have about the same corrosion potential. The excep-tions are rolled, extruded, and forqed aluminum (anisotropic qrain structure) which havebeen heat treated or cold worked. These alloys are susceptible to exfoliation corrosion.


A': 43-204 8/14/97

FIGURE 1-21.GALVANIC CORROSION OF MAGNESIUM ADJACENT TO STEELFASTENER (Courtesy of Thomas Flournoy)

Page 28Chap 1Par 12

a/14/97 AC 43-204The rate and degree of corrosion depends on the relative surfaceareas of the two metals and their location on the electromotiveforce series. Adjacent metals in the EMF series have low corro-sion susceptibility whereas widely separated metals will corroderapidly. For example, an aluminum fastener in contact with arelatively inert Monel (nickel, copper, steel) structure may cor-rode severely, while a Monel bracket secured to a large aluminummember would result in a relatively superficial attack on thealuminum sheet.

i. concentmtion Cell or Crevice Corrom . Concentrationcell corrosion is corrosion of metals in a metal-to-metal joint;corrosion at the edge of a joint, even through joined metals areidentical; or corrosion of a spot on the metal surface covered bya foreign material (see Figure 1-22 for the three types of crev-ice corrosion).

I---LOW METAL ION CONCENTRATION HIGH OXYGEN CONCENTRAT ION

HIGH WETAL ION CONCENTRATION LOW OXYGEN CONCENTRATION

METAL ION CONCENTRATION CELL OXYGEN CONCENTRATIOI~ CEL;RIVETED LAP JOINT

PASSIVE FILMPROTECTS EX

FOREIGN MATERIAL CREATESLOW OXYGEN REGION WUICH

NTS THE RE-FORMATIONOF PASSIVE FILM

METAL ACTIVE - PASSIVE CELL

FIGURE 1-22. CONCENTRATION CELL CORROSION

j . Intexaranular Corrosion. Intergranular corrosion is anattack along the grain boundaries of a material. Rapid selectivecorrosion at the grain boundary can occur with subsequent delami-nation (see Figure l-23). High-strength aluminum alloys such as2014 and 7075 are more susceptible to intergranular corrosion ifthey have been improperly heat-treated and are then exposed to acorrosive environment.


A': 43-204 8/14/97

FIGURE l-23. INTERGRANULAR CRACKING AND CORROSION ONA WINGSPAR CHORD

. .k. Exfollatlon Corrosion . Exfoliation corrosion is an ad-vanced form of intergranular corrosion where the surface grainsof a metal are lifted up by the force of expanding corrosionproducts occurring at the grain boundaries just below the sur-face. The lifting up or swelling is visible evidence of exfolia-tion corrosion (see Figure l-24). Exfoliation is most prone tooccur in rolled and wrought products such as extrusions, thicksheet, thin plate, and certain die-forged shapes. This is incontrast with cast products that tend to have a more homogeneousgrain structure.

Page 30Chap 1Par 12

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13.-199.

Chap 1Par 12

AZ 43-204

FIGURE l-24. SEVERE EXFOLIATION CORROSION(Courtesy of Thomas Flournoy)

RESERVED.

Pages 31 through 42

a/14/97 AC 43-204

CHAPTER 2. VISUAL INSPECTION PROCEDURES

200. GENERAL. Generally, the inspection procedure to be usedwill be specified by the aircraft or component manufacturers orthe FAA in documents such as maintenance or overhaul manuals,A D ’ S , SSID's, or manufacturers' Service Bulletins. If, duringmaintenance, a condition is found on the aircraft being inspectedwhich may recur on that aircraft or on another of its type, acertified inspector or other appropriate individual should createan inspection procedure covering the condition. Approval of suchprocedures should be in accordance with appropriate FARs.

201. MATERIAL CONTAINED IN A VISUAL INSPECTION PROCEDURE. Visualinspection procedures should all contain steps in a logical for-m a t . A procedure has four basic parts: (1) a basis for the in-spection, (2) preparatory arrangements, (3) implementation of theinspection, and (4) evaluation of the results. Table 2-1 is alisting of all the elements to be considered when creating or re-viewing an inspection procedure. Each of the items in the Tableshould be addressed in the procedure if relevant for the specificinspection.


AC 43-204 8/14/97

TABLE 2-l. TOPICS TO BE CONSIDERED IN PREPARING ORREVIEWING A VISUAL INSPECTION PROCEDURE

BASIS FOR INSPECTION

Reason for and purpose of the inspection including any relevant background infor-mation.

References to controlling documentation, for example: Advisory Circulars, Airwor-thiness Directives, Manufacturers and general NDT Manuals, Maintenance and otherrelevant manuals.

Controlling dates: Effective date of the inspection, date before which the in-spection should be accomplished, inspection interval, date at which the inspectionno longer is necessary.

I Effectiveness; aircraft, engine, or part number. II - -Time and labor required for the inspection.

Conditions under which the inspection is no longer necessary.

PREPARATION

Preparation and cleaning of the item being inspected.

Any special requirements of the inspection such as unusual surface preparation(etching, paint removal) or the temperature range over which the inspection is ef-fective.

I Identification of any equipment necessary for the inspection together with provi-sions for periodic calibration thereof. I

of the specific materials approved for the inspection. These maybe included in a referenced Qualified Products List.

IMPLEMENTATION

Specific description of the area to be inspected.

Instructions for carrying out the inspection.

Description of the defect to be detected, preferably with an illustration of asamole defect.

1 Postcleanina instructions if required.

Instructions for disposition of the article if it cannot be returned to service.

EVALUATION

Procedure for establishing inspection reliability.

Accept/re]ect criteria.

ReDOrtinQ requirements.

202. ACTIVITIES APPLYING TO ALL VISUAL INSPECTIONS. Some activi-ties which represent good practice may not be specifically calledout in the procedures, but should be completed if they are rele-vant. Examples of such good practice are:

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a/14/97 AC 43-204

a. Preliminary Inspectioq. A preliminary inspection of theoverall general area should be performed for cleanliness, pres-ence of foreign objects,of parts, corrosion,

deformed or missing fasteners, securityand damage. If the configuration or loca-

tion of the part conceals the area to be inspected, it is appro-priate to use visual aids such as mirror or borescope.

b. Precleaninq. The areas or surface of parts to be in-spected should be cleaned without damaging any surface treatmentwhich may be present. Contaminants that might hinder the discov-ery of existing surface indications should be removed. Somecleaning methods may remove indications of damage; care should beused if the cleaning tends to smear or hide possible indicationsof trouble. Surface coatings may have to be removed at a latertime if other ND1 techniques are required to verify any indica-tions that are found. Some typical cleaning materials and meth-ods used to prepare parts for visual inspection are detergentcleaners, alkaline cleaners, vapor degreasing, solvent cleaners,mechanical cleaning, paint removers, steam cleaning, and ultra-sonic cleaning.

C . Corrosion Treatment. Any corrosion found in the prelimi-nary inspection should be removed before starting a close visualinspection of any selected part or area. Manufacturers' hand-books, when available, are a good general guide for treatment ofcorrosion. Recommendations of AC 43-4A, if appropriate, shouldbe used on aircraft for which the manufacturer has not publisheda recommended corrosion inspection schedule or treatment program.The AC contains a summary of current available data regardingidentification and treatment of corrosion on aircraft structureand engine materials. Examples of types of corrosion damage de-tectable by the visual method are also given.

d. Use of Visual Aids. When inspecting the area required,visual aids should be used as necessary. An inspector normallyshould have available suitable measuring devices: a flashlightand a mirror. Chapter 3 provides information on lighting tech-niques that can be used when inspecting for defects in differenttypes of materials.

203. RECORD KEEPING. All defects found should be documentedby Maintenance Record entry, written report, squawk sheet, photo-graph, or video recording for appropriate evaluation. Dependingon the rules governing the facility and person performing the in-spection, the report may be limited to simply reporting findingswithout any rejection or acceptance disposition. The type, loca-tion, and approximate size of any defects present should be docu-mented. Based upon the particular inspection process specifica-tion (i.e., AD, Service Bulletin, Maintenance Manual requirement,or normal inspection discovery) the mechanic, repairman, or otherauthorized person should determine the particular acceptance, re-


AC 43-204 8/14/97

work, repair or rejection status of the part or structure beinginspected.

a. Findinss. One of the most important elements of the vis-ual inspection process is the nature of the report of findings.As a guide, the record of findings for any defects should be keptin a manner as to permit others who may be doing the same inspec-tion to have the benefit of any previous information found andexperience gained.

b. Maintenance of Records. The full value of visual inspec-tion can be realized only if records are kept of the conditionsfound on parts inspected. The size and shape of the finding andits location should be recorded along with other pertinent infor-mation, such as rework performed or disposition. The inclusionof some permanent record of a defect on a report makes the reportmuch more complete.

C . Illustrations as Records. It should be stressed thatfrequent and effective use of illustrations not only will enhancethe effectiveness of the procedure but is indispensable in commu-nicating to the inspector the nature of the defects to be found.In addition to textual and anecdotal data, the following types ofrecords are commonly used:

(1) Sketches. The simplest record is a sketch of thepart showing the location and extent of the defect. On large ar-eas it may be sufficient to sketch only the critical area.

(2) Photosraohv. Photographs (still or video recording)of defects can be taken for visual record purposes. Photographsproduce a permanent and highly descriptive record since they showboth size and location on the part. They are permanent, repro-ducible, and the required equipment is readily available. It isgood practice to include a scale in the photo when practicable aswell as some marking for identification. This is particularlynecessary if the photograph is likely to become an exhibit in-volved in litigation.


8/14/97

204. FOUR LEVELS OF VISUAL INSPECTION.

AC 43-204

a. Inspection Tasks. Visual inspection tasks are dividedinto four categories relating to their difficulty and degree ofeffectiveness as follows:

l Walkaround Inspection.l General Visual Inspection.l Detailed Visual Inspection.l Special Detailed Visual Inspection.

b. Additional Soecial NDI. An additional category may beused when visual inspection is supplemented by special-ized ND1 equipment.

205. ACCEPTABLE PRACTICE FOR VISUAL INSPECTION. Acceptable prac-tice for the four levels of visual inspection is defined in thefollowing paragraphs. For each level, the practice is dividedinto the four parts of the inspection procedure described in Ta-ble 2-1. Details of the inspection procedures will vary for dif-ferent types of operators and aircraft; for example, the walk-around for a general aviation aircraft and a commercial jet willhave major differences. It is important however, that the proce-dure for each aircraft type in a given service be carried outwith the same care and detail every time the aircraft is in-spected. Also, in all inspections described herein, the inspec-tor should have available and be familiar with the documentationand reporting forms and the ground rules mandating the inspec-tion. Refer to Appendices A through F for sample visual inspec-tion procedures and equipment.

a. Level 1. Walkaround. The walkaround inspection is ageneral check conducted from ground level to detect discrepanciesand to determine general condition and security.

NOTE: This is the only one of the four inspectionsthat may be accomplished by either flight or mainte-nance personnel. The focus and perspective will varybased on the relation of the inspection to flight ormaintenance operations.

(1) Basis for Inspection. Most maintenance instructionsmandate walkaround inspections on a periodic basis. The overallpurpose is to serve as a quick check to determine if detectableinconsistencies exist which would affect the performance of theaircraft.


AC 43-204 8/14/97

(2) Preoaration for the Insoection. Aircraft historyshould be used to gain information useful in inspecting the air-craft (e.g., are there recurring problems or have there been hardlandings?). In addition the aircraft should be clean enough foran effective inspection to take place, the necessary tools andequipment should be available (e.g., flashlight, rag, notebook),and other aids, tools, and procedures may be necessary (e.g., in-spection of some aircraft is easier if already on jacks, but thisis not always necessary).

(3) Implementation. Beginning the inspection at thenose, the inspector should approach the inspection from the per-spective of the pilot and mechanic by, first, determining generalcondition and, second, identifying maintenance items. A goodrule is to check for items affecting safety, legality, effi-ciency, and comfort. The following paragraphs give a partiallisting of things to look for. Each aircraft will be different,but a surprising number of different aircraft have similar struc-tural details.

l Observe left and right side of fuselage and leftand right wings. (Does the aircraft list?) Work toyour left. Check general condition of paint.Check exterior surface components within reach.Check windows. Check engine, propellers or fanblades, exhaust area, and pylons. Check leadingedges everywhere. Check control surfaces for slop,wear, and security. Check each gear well. Checkall entry and exit points to the aircraft. Checkstatic dischargers. Observe surfaces at differentangles using available light to enhance surfaceevaluation.

l Examine according to what the standard conditionis. (Question the existence of any unusual condi-tion.) Look for anything different from one sideto another. (It is important to shake, push, pull,listen, and feel when possible.) Run your handover skin junction areas or composite surfaces.

l Walk around twice. (Observations during the firstcursory walkaround the aircraft should be used todetermine the general condition. On the secondtime around revisit the areas noted on the initialwalk and look for other discrepancies that may berevealed through closer scrutiny of a specificarea. This is when specific locations should beobserved.)

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l Are there major dents or intrusions in the skin?Look for evidence of flexing parts, waves in theskin, weave or bubble in fiber glass or compositecomponents, eroded fairings, and bulging or flat-tened seals. Are any external components bent? Isthere evidence of damage? Check windows for craz-ing, dirt, and pitting.

l Rivet characteristics should be noted. Observerivets for damage. Look for loose broken or miss-ing rivets. Localized chipping of paint, crackedpaint on sealant, or fretting corrosion are indica-tive of movement. Look for smoked or stained riv-ets.

l Check all venting for leaks. Check all input tub-ing to insure it is clear. Check all antennas forchipping and strikes. Check for obstructions inpitot tubes, static and engine pressure orifices,and temperature venturies.

(4) Findinss. Initial findings should be recorded in apersonal notebook as soon as discrepancies are discovered. Donot rely on memory. Findings should be transferred to the air-craft log or official record of discrepancy as soon as possible.Recommendations for action will depend on whether the inspectionprecedes flight operations or maintenance and whether the dis-crepancy is safety or flight critical.

b. Level 2. General. A general inspection is made of an ex-terior with selected hatches and openings open or an interior,when called for, to detect damage, failure, or irregularity.

(1) Basis for Insnection. When a specific problem issuspected, the general inspection is carried out to identify, ifpossible, the difficulty. General inspections are also routinelyused when panels are open for normal maintenance.

(2) Preparation for the Insoection. Ensure cleanlinessof the aircraft. The necessary tools and equipment required mayinclude flashlight, mirror, notebook, droplight, rolling stool,tools for removal of panels, ladders stands, or platforms. Otheraids such as jacking of the aircraft may or may not be discre-tionary; knowledge of a specific aircraft may be essential; andcommon problems may require information, even if not on the in-spection card.

(3) Implementation. General looking is not enough. Asthe inspector, you should continually ask “What is wrong withthis picture?" Be inquisitive. Question whether you have seen


AC 43-204 8/14/97

this before. Move, shake, pull, twist, and push all parts possi-ble. Apply weight to load bearing components. Compare one sideto the other if applicable. Be aware of other systems in the in-spection area. Look for abnormalities in the area, even if notrelated to this inspection. Adjusting the source of illumina-tion, view items under inspection from different angles. Is thearea pressurized? If so, does this affect any part of the in-spection? Inspect all structural components, all moveable parts,all attach points, and brackets. Check all cables, conduits, andhoses for condition and clearance. Check condition and securityof load and stress points. Look for chafing and fretting corro-sion. Observe proximity of one part to another. Look for looseor missing fasteners, use of proper sealants, noticeable cracks,indications of corrosion, and debris in closed areas. Observethat cables, conduits, and hoses are properly routed. Observethat there is sufficient strain relief. Observe rivets for dam-age. Look for smoked rivets and discoloration of paint.(Localized chipping of paint, cracked paint on sealant, or fret-ting corrosion are indicative of movement.)

(4) Findinss. Transfer all information relating to dis-crepancies from your notebook. Record discrepancies as a workorder. Discoveries during the inspection may indicate the needfor a more detailed inspection. Depending on the findings, thismay be either a Level 3 or Level 4.

C . Level 3. Detailed. A detailed visual inspection is anintensive visual examination of a specific area, system, or as-sembly to detect damage failure or irregularity. Available in-spection aids should be used. Surface preparation and elaborateaccess procedures may be required.

(1) Basis for Inspection. A detailed inspection iscalled for when a specific problem is suspected and the generalinspection dictates additional inspection. Or, if the inspectionis otherwise mandated, a detailed visual inspection is carriedout to identify, if possible, the difficulty. Detailed inspec-tions are also periodically called for on damage-tolerant air-craft to ensure the airworthiness of the critical structure.

(2) Preparation for the Insoection. Tools and equipmentwill vary, but may include a prism, supplemental lighting, mir-ror, magnifying glass, flashlight, dye penetrant, notebook, drop-light, rolling stool, and standard and specialized hand tools.Documentation required is specific to the procedures outlined bysteps on work cards. Also review the SBs, ADS, aircraft history,and accident reports. Other aids such as knowledge of a specificaircraft and common problems may be essential even if not on theinspection card.

(3) Imolementation. The reasoning that originally dic-tated the inspection should be considered. If it was because

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some corrosion was found, then a more in-depth examination is re-quired. If the inspection is in response to an AD for a crack,carefully inspect the surrounding area to rule out additional oc-currences or stress induced because of the crack. In a detailedinspection, you are usually searching for failure, damage, or ir-regularity. Check the condition and security of lockwires andthe load and stress points. Look for fretting corrosion. Ob-serve proximity of one part to another. Look for loose or miss-ing fasteners, use of proper sealants, obvious cracks, indica-tions of corrosion, and debris in closed areas. Observe that ca-bles, conduits, and hoses are properly routed. Observe thatthere is sufficient strain relief. Look to see if any chafinghas occurred.

(4) Findinss. Recommendations (discoveries during thisinspection may indicate the need for a more detailed inspection,such as a Level 4).

d. Level 4. Special Detailed. A special detailed inspec-tion is an intensive examination of a specific item, installa-tion, or assembly to detect damage, failure, or irregularity. Itis likely to make use of specialized techniques and equipment.Intricate disassembly and cleaning may be required.

(1) Basis for Inspection. As systems and structureshave become more complex, special inspections using extraordinarytechniques and equipment have evolved to ensure airworthiness.These are covered in instructions for special detailed inspec-tions. Special detailed inspections are also periodically calledfor on damage-tolerant aircraft to ensure the airworthiness ofthe critical structure. This level of inspection may also be in-voked based on recommendations from a lower level.

(2) Prenaration for the Insoection. Tools and equipmentwill vary but may include a flashlight, mirror, video borescopes,special aids and tooling, Dremel, rolling stool, image enhance-ment and recording devices, supplemental lighting, magnifyingglass, dye penetrant, notebook, and standard and specialized handtools. Documentation required is specific to the procedures out-lined by steps on work cards; review of SBs, ADS, and aircrafthistory; and reference to the original or referred discrepancy,if any. Another aid is the discrepancy report from the contract-ing ND1 company.

(3) Imolementation. Procedures are defined in detail bythe specific instruction procedure, but they are limited to thescope of visual inspection. The locations to be inspected willvary greatly, but may include portions of the aircraft that areinaccessible without major disassembly, such as the interior sur-face of the wing skin, pylon butt joints, and lap joints. Insome of these cases the objective of the inspection may be best


AC 43-204 8/14/97

served both practically and economically through the use of ND1techniques.

(4) Findinus. Satisfy documentation that specified thislevel of inspection. Documentation will be both internal and ex-ternal and may include work cards, ADS and SBs. Recommendationsshould include recommendations for correction of the discrepancyand follow-up inspection.

206.-299.

Pages 52 through 62

RESERVED.

Chap 2Par 205

8/14/97

CHAPTER 3. VISUAL INSPECTION AIDS

AC 43-204

300. GENERAL. The two indispensable aids to visual inspectionare illumination and optical aids of various types. Illuminationand lighting are crucial to all forms of visual inspection andcan vastly affect the inspection outcome. In the following sec-tions these two elements of the inspection process will be dis-cussed. In the lighting section, all the aspects of lighting inthe inspection environment are discussed.ing visual aids,

In the section cover-most optical devices which have found utility in

aircraft inspection are described.

a. Tools. It should be emphasized that eye-mirror-flashlight is an indispensable combination for visual inspection.Aircraft structure and components requiring inspection are fre-quently located beneath skin, cables, tubing, control rods,pumps, and actuators. Therefore,flection is often essential.

good secondary access by re-

sist of a strong flashlight,Visual inspection aids usually con-

to 5-power simple magnifier.a mirror with a ball joint, and a 2-The mirror should be of adequate

size (except for very awkward access situations) with reflectingsurface free of dirt, cracks, and worn coating; and the swiveljoint should be tight enough to maintain its setting.ing mirror may be useful in some situations.

A magnify-A lo-power magni-

fier is recommended for positive identification of suspectedcracks; however, other ND1 techniques,magnetic particle,

such as dye penetrant,

dications.or eddy current can also be used to verify in-

Visual inspection of some areas can only be accom-plished with the use of remote viewing devices, such asborescopes and video imaging systems.

b. Special Techniques. Visual inspection is a ubiquitousprocess used in many locations and involves numerous specialtechniques. Each will have an optimum lighting environment andits own types of visual and optical enhancements. It is up tothe inspector to select the appropriate illumination and opticalaid for the inspection at hand.

301. LIGHTING AND ILLUMINATION. Federal Aviation Regulation,Section 145.35(g) dealing with facilities requires that lightingshould be adequate for the work being performed and should notadversely affect the quality of the work. Such lighting can beprovided by a combination of general background and supplementalillumination and will vary with practice and be task dependent.

The amount of light needed to perform the variety of seeing tasksin visual inspection of aircraft and related components dependsnot only on the task itself, but also on the vision and the ageof the worker (vision may need correcting with glasses and older


AC 43-204 8/14/97

eyes require more light), the importance of the task (how criti-cal or expensive is a mistake), and the reflectance of the taskbackground (the greater the difference between task and back-ground, the easier it is to see).

a. General Considerations for Lishtins Aircraft MaintenanceAreas. The follotiing factors should be considered as all-important requirements of good planning for aircraft maintenancelighting systems:

(1) Safetv of Personnel. Determine the quantity, qual-ity, and type of illumination desirable for safety of personnel,the maintenance processes, and the environment.

(2) Selection of Lishtins Eauipment. Select lightingequipment that will provide the quantity and quality requirementsby examining luminance characteristics and performance that willmeet installation, operating, and actual maintenance conditions.

(3) Equipment Maintenance. Select and arrange lightingequipment so that it will be easy and practical to maintain.

(4) Enerqv Manaqement. Energy management considerationsand economic factors, including initial operating and maintenancecosts versus the quantity and quality requirements for optimumvisual performance, should be balanced (reference IES handbookson lighting, also see Appendix G in this document). Wheneverpossible, the use of daylight should be considered for mainte-nance areas. Due consideration should be given to the NationalEnergy Policy Act of 1992 covering the use of energy efficientillumination.

b. Illuminance Values. The IES has provided a range of il-luminance values and illuminance categories to be used for ge-neric types of interior activities when specific recommendationsare not available (see Table 3-l).


a/14/97 AC 43-204

TABLE 3-1. ILLUMINANCE VALUES

ILLUMINANCE CATEGORIES AND ILLUMINANCE VALUES FOR GENERICTYPES OF ACTIVITIES

RANGE OF1 ILLUMINANCE

TYPE OF ACTIVITY CATEGORYPublic spaces with A

Working spaceswhere visual tasksare only occasion-ally performedPerformance of vis- Dual tasks of highcontrast or smallsizePerformance of vis- I Eual tasks of mediumcontrast or smalls i z ePerformance of vis- Fual tasks of lowcontrast or very Is m a l l s i z ePerformance of vis- Gual tasks of lowcontrast or verysmal l s ize over aprolonged periodPerformance of very Hprolonged and ex-acting visual task

I

Performance of very I Ispecial visual -tasks of extremelylow contrast andsmal l s i ze

spaces10-15-20

20-30-50

50-75-100 11 luminanceon task

tained by acombination

) of general1 and local(supplementary lighting)

The IES has also established a procedure (range approach) for se-lecting illuminance values from the ranges listed in Table 3-l by


AC 43-204 a/14/97

using a weighting-factor guidance system, reflecting lighting-performance trends found in research (see Table 3-2). It was es-tablished to accommodate a need for flexibility in determiningilluminances so that lighting designers could design lightingsystems to meet specific needs. Such flexibility requires thatadditional information be available to effectively use the rangeapproach. To use the range approach, a lighting task should beconsidered to be composed of the following elements:


~1; Liqktins Task Zlements.

(i) Visual Disnlay.ject being viewed,

The visual display is the ob-which is presumed to present some inherent

difficulty of observation.

(ii) Observer Acre. The age of the observer is afactor in the observer's visual performance.

(iii) Sneed and/or Accuracy. The importance ofspeed and/or accuracy distinguishes between casual, important,and critical seeing requirements.

(iv) Task Reflectance. The reflectance of the task(background against which the details are seen). The reflectancewill determine the type of illumination best adapted to the re-flectance characteristics of the visual display.

(2) Amount and Type of Light. The above lighting taskelements should be considered concurrently to determine the ap-propriate amount and type of light for the lighting task. Addi-tional information on using this range approach procedure for se-lecting illuminances is provided by the IES in its handbooks onlighting, and in Appendix G of this document.

C. Industrial Lishtinq.lighting recommendations,

In addition to generic-activitythe IES through technical committees

and knowledgeable individuals provides lighting recommendationsfor specific industries. Table 3-3 provides the IES recommendedilluminance categories for general industrial inspectionarea/activity. The IES standards contain lighting recommenda-tions for specific tasks and areas in aircraft maintenance.

TABLE 3-3. IES RECOMMENDED ILLUMINANCE CATEGORIES FOR THEDESIGN AND EVALUATION OF LIGHTING SYSTEMS FORINDUSTRIAL INSPECTION AREAS

INDUSTRIAL GROUP (*Inspection Area/Activity Only)Area/Activity Illuminance Category**

InspectionSimple DModerately Difficult EDifficult FVery Difficult GExacting H

The :ES provides a wide variety o f ~ndustrlal area/actlvl~y recommendations for Llluml-nance .z ateqor~es ln t h e Industr:al Group.

. . See T a b l e 3-1.


fii: 43-204 B/14/97

d. Seeing Tasks. The seeing tasks required for visual in-spection of aircraft tend to be three dimensional and curved,rather than two dimensional and flat like seeing tasks found inan office. The seeing task can be almost any distance from thefloor, compared with 30 inches for the typical desk top, and inany position from horizontal to vertical. The seeing task canhave extremely fine detail requiring thousands of footcandles orbe so large that lower levels will suffice. The finish of thearticle to be inspected (dull or matte versus shiny or mirror-like versus brushed) greatly affects the amount and orientationof the lighting needed for good visibility.

Good visual inspection lighting depends not only on providing theright illumination levels, but also on selecting the proper lampand luminaire and mounting or positioning it in the right loca-tion. In fact, the latter can often have far more effect on taskvisibility than the lighting level. Figures 3-1, through 3-3show examples of the effects of article finish and lighting ori-entation on visibility. The shiny and matte finish micrometers,shown in Figure 3-1, typify a range of seeing tasks and the ef-fect of lighting system orientation. The graduations on the bar-rel of the matte finish micrometer are highly legible under allthree lighting conditions: fluorescent parallel to the barrel(Figure 3-lA), fluorescent perpendicular to the barrel (Figure 3-1B) , and high-intensity discharge (HID) downlight (Figure 3-1C).

..--___

A B C

FIGURE 3-1. EXAMPLE OF THE EFFECT OF SHINY AND MATTE FINISH OFPARTS AND LIGHTING SYSTEM ORIENTATION ON SEEING TASKS(Courtesy of General Electric Company)

The graduations of the shiny micrometer cannot be easily readwhen the barrel is parallel to the fluorescent lighting (Figure3-1A) because of lines of glare. When the lighting is perpen-dicular (Figure 3-lB), the reflections wrap around the surface,


8/14/97 AC 43-204the contrast is improved substantially, and the graduations areeasily legible. The downlight system (Figure 3-1C) tends to beomnidirectional and the legibility of the numbers is intermediatebetween parallel and perpendicular fluorescent lighting.

The solder connections on the circuit board, shown in Figure 3-2,are difficult to inspect because of the reflections of the brightHID downlight (Figure 3-2A). Under the large, low-brightnessfluorescent luminaire (Figure 3-2B), the reflections are soft anddiffuse and defects can be easily detected.

A B

FIGURE 3-2. EXAMPLE OF THE EFFECT OF LIGHTING SYSTEMS ONINSPECTION OF A CIRCUIT BOARD(Courtesy of General Electric Company)

Scribe marks, shown in Figure 3-3, (and many defects) on polishedor lightly etched surfaces are more visible if they are parallelto the fluorescent lighting (Figure 3-3A) rather than at rightangles to it (Figure 3-3B), since the surface reflects the darkerarea between the fixtures and increases the contrast.


AC 43-204 8/14/97

’ . :

,,,I. .,_^“...I__-

FIGURE 3-3. EXAMPLE OF THE EFFECT OF LIGHTING SYSTEMORIENTATION ON AN INSPECTION SURFACE(Courtesy of General Electric Company)

e. Classification of Visual Tasks and Liahtina Techniaues.Visual tasks are unlimited in number, but some can be classifiedaccording to certain common characteristics. The detail to beseen in each group can be emphasized by an application of certainlighting fundamentals. Table 3-4 classifies tasks according totheir physical and light-controlling characteristics and suggestslighting techniques for good visual perception.


8/14/97 AC 43-204

TABLE 3-4. CLASSIFICATION OF VISUAL TASKS AND SUPPLEMENTARYLIGHTING TECHNIQUES (Sheet 1 of 3)


AC 43-204 B/14/97


PART I FLAT SURFACES (Continued1CIASSI FICATION OF

VI SUAL TASK EXAMPLE SUPPLEMENTARY LIGHTING TECllNIQUEGC?neral I.iqht lnq Luminai re

CharJctcrlstlcs D e s c r i p t i o n Hequi rements Type* L o c a t e L u m i n a i r ec.., T r a n s p a r e n t Materialsclear mater-la1 w i t h P l a t e qlass T o product visl- S - V a n d S - I T r a n s p a r e n t mate-nlrror f i n i s h s u r f a c e b i l i t y o f details rial s h o u l d move

wl t h i n m<lt c-rid1 i n f rant o f T y p es u c h as b u b b l e s , s - v , t h e n i n f r o n tand drtalls o n o f b l a c k back-surf <act surh as qrourld w i t h Type:;<:r,~t the:; :;-I direct c d

o b l i q u e l y . ‘I’ ypeS - I s h o u l d b e d i -r e c t e d t o p r e v e n tglarr

I) . ‘rransprcnt over Opa2ur M a t trial:;1. T r a n s p a r e n t mate- I n s t r u m e n t Maximum vlnlbillty S - I s o reflcct1on o frlal over d d i f f u s e panel o f s c a l e a n d source d o e s n o tt,,lrkyrou”d polntrr w i t h o u t coincldc w i t h an-

vri I ~riq r e f lrsc- qle of viewt 10”s

M.lx1rnum v1~ilblllty S - V so that Imdy’ o fc f dc*t .I 1 1 on ml I - :;O,,ICC a n d pattrrnror f ,ril:;h back- 1:; rcsflected t o(11 OlllKi t hc, cyc’

[‘ART I I ‘I’IlHF:E I)IMf.:NSIONAI, OHJECTSCLASSIFICATION OF‘

VISUAL TASK EXAMPLE SUPPLEMENTAHY LIGHTING TECHNIQUEGener‘ll Llqht 1ng Luml nd 1 rc

chdrdcter 1st its Dcascri t lorl Rc,qu i rcmc’nt s Typr+ I.ocatc LuminairclR. op;~quct Mat <‘rl al:;1 Diffuse detail a n d D i r t o n ,7 T o emphasize dc- S - I I I o r S - I I T o p r e v e n t directL)d<:kqrou”d c a s t inq or t 411 w i t h rl p o o r o r ql~rc a n d s h a d o w s

t, I 0” ho 1 c’:; <‘o”t r;l:;tI” ,a cdSt1”c) S - I o r I” reldtlo” to task

t.o e m p h a s i z e dctallb y mrans o f hiqh-1 ~qht <Ind shadow

S - I I I o r s-11 T o dlrcct ultravlo-as d b l a c k let radlatlon t o a l l1 Iqht sourc? ~,ol”t pi t o t,c. chcckcdw h e n o b j e c th a s rl f luo-rcsccnt corlt-i n q

Page 72Chap 3

Par 301

a/14/97 AC 43-204


PART II THREE DIMENSIONAL OBJECTS IContinued

CIJ\SSIFICATION OFVISUAL TASK EXAMPLE SUPPLEMENTARY LIGHTING TECHNIQUE

Genera l Liqhtinq Lumina i reCharacteristics Description R e q u i r e m e n t s T y p e * Locatc L u m i n a i r e

2. M i r r o r finish d e t a i l a n d b a c k g r o u n d

d . Detail o n t h e sur- D e n t i n pol- T o emphasize sur- s - vface

T o r e f l e c t i m a g e o fished alum1 - face unevenness source e yenum s k i n

I nspcct i 0” To show up dreds S - I V pi,,:; ‘I’0 ret lcct imaqc o fof f In\!;tl not pr”pt!r ly proper cx,lor source t o e y eplat 1nq over p 1 rl t <viundrrplat lrlq

t>. I)c?rall 1” the! sur- Scrdtch o r T o c?mph,ls1 7~ sur- S - I V T o r e f l e c t Image o f1 clc‘e c r a c k o n f .l(:o b r e a k source t o e y e

p o l i s h e da l u m i n u ms k i n

.3 . Combination mirror f i n i s h a n d diffusecl. M i r r o r f i n i s h de- Scr ibe mark To make l i n e qllt.- S - I I I o r S - I I I n relation t o t a s kt.311 011 d i f f u s e back- on cast1nq t c’r aqainst dul 1 f o r b e s t visibility.qrou”d b<lc:kqround Ad jus tab l e equ ipment

o f t e n helpful.Overhead t o rrf lcct1 rn‘jqe o f source t o(I yc

t>. I)I f f us<! detal 1 011 Mlcromcster ‘I‘[) c:rcsdt n 1 urns nous S - I V 01 S - I I With axis n o r m a l o fml! IOI f lrllsh back- sc‘lle ~><1<:kclround dqdlnst micrometer~~rr)urld which :;<.alc: mark-

l,l<]S <‘d” t,t, see,,111 hl(]h cant rast

Ii. Translucent MaterldlsI I)1 f fuse surfac:cz Intc~r~or To show impcrfcc- S - I I Uehlnd o r wlt.hln f o r

1 lyht 1 “q t lo”:; irl material translllumlnatlondl f t users

7. Mirror finish sur- G l a s s en- To emph<is1 zc sur- S - V O v e r h e a d t o r e f l e c t1 .1 (.I> rl0:;l”q 1 r,re ,rrc!qularl- imaqe o f s o u r c e t o

q 1 obcp, t 1 r:i <‘yef r 0:s t cd 1 <,,,:iC‘O”P r Tc> r.tif,c-k hr,moqc~rre- .?-I1 13~hind o r wit hln f o r

1ty t ransillumlnatlon(:. Tr<~r,:;p<‘rc~r,t Mat vr ~~1s

(:lc%.jr materldl with Wirldshlclds T o cmph‘rsi %c sur- S - I T o b e d i r e c t e dml rror f inlsh sur f a c e f ,,cv 1 I r We,, 1 d I 1 - obl i q u c l y t o ObJects

t 1esHchirld f o r transll-

‘rcl vrnptr,l:;l i(l S-IV o r s-v lumlnatlorl. M o t ionc r a c k s , chips, a n d o f o b j e c t s h e l p f u lforc1qn part1clrs

f. Qualitv of Illumination. Quality of illumination per-tains to the distribution of luminances in the visual environ-ment. The term is used in a positive sense and implies that allluminances contribute favorably to visual performance, visualcomfort, ease of seeing, safety, and esthetics for the specificvisual task involved. Glare, diffusion, direction, uniformity,color, luminance, and luminance ratios all have a significant ef-fect on visibility and the ability to see easily, accurately, andquickly. Certain industrial seeing tasks, such as visual inspec-tion, require discernment of fine details and need much morecareful analysis and higher quality illumination than others.


liC 43-204 8/14/97

Whenever possible, the quality of illumination for the particularvisual inspection task being performed should be checked, includ-ing the use of test parts with discontinuities of the type beingsought. Areas where the seeing tasks are severe and performedover long periods of time require much higher quality than whereseeing tasks are casual or of relatively short duration. Indus-trial lighting installations of very poor quality are easily rec-ognized as uncomfortable and are possibly hazardous. Unfortu-nately, moderate lighting deficiencies are not readily detected,although the cumulative effect of even slightly glaring condi-tions can result in substantial loss of seeing efficiency and un-due fatigue.

(1) Glare, General. Glare is unwanted light in thefield of view which causes loss in visual performance and visi-bility. It occurs when luminances within the visual field aresubstantially greater than the amount of luminance to which theeyes are adapted. It can be caused by a source of light (directglare) or can be reflected from any surface in the room includingthe task (reflected glare).

(2) Direct Glare. Direct glare is often the result ofthe luminaire not shielding the lamp from view (see Figures 3-4Aand 3-4B). It may be noticeably severe with lamps of high lumi-nance values. For example, a clear 250-watt, high-pressure so-dium lamp that emits 27,500 lumens from a cigarette-size arc tubewill be much brighter than a 400-watt, metal-halide lamp emitting36,000 lumens from a melon-size, phosphor-coated lamp envelope.Portions of some mirrored reflectors can reflect an overly brightimage of the lamp (see Figure 3-4C). Lens-enclosed luminairesmay eliminate bare-lamp brightness, but can themselves cause di-rect glare at certain angles. Fluorescent luminaires, with theirrelatively low-brightness lamps, usually will be less glaring.Avoiding direct glare is simply a matter of choosing the rightluminaire and its location.

(3) Reflected Glare (Veilinq Reflection). Reflectedglare is somewhat more insidious than direct glare. Images ofthe lamps or the luminaires are reflected from the viewing task(see Figure 3-4D). These veiling reflections can be severeenough to cause errors during visual inspection. The followingsuggestions are provided for avoiding reflected glare:

l Change the position of the viewing task and/or theoffending luminaire(s), if practicable. This willchange the angular relationship between the lightsource, task, and observer, thereby directing theoffending reflection elsewhere.

l Use a dull or matte finish, not a shiny one, onsurfaces surrounding the task such as the machin-ery, tools, benches, walls, etc.


g/14/97 AC 43-204

l Replace clear lamps with diffuse-coated ones.

C D JFIGURE 3-4. EXAMPLES OF DIRECT AND REFLECTED GLARE

(Courtesy of General Electric Company)

l Change the lighting system, if required. For ex-ample, replace HID downlight luminaires with thosethat have large-area lenses (large surfaces willbe less bright and reduce reflections) or withfluorescent.

. Use a large-area fluorescent lighting system. Thereflections will be uniform and low in luminance.A translucent panel system is often recommendedfor inspecting mirrored metal and plastic articlesfor surface defects.


AC 43-204 8/14/97

l Use specialized supplementary lighting where theglare problem is limited to a few locations.

9. Luminaire Shielding. The purpose of a luminaire is tocontrol or direct the light from the lamp. This is accomplishedby the size, shape, and material of the reflector and auxiliarydevices such as baffles, louvers, lenses, and diffusers.

For industrial lighting applications, including inspection areas,shielding should be at least 25 degrees and preferably approach-ing 45 degrees (see Figure 3-51, especially in areas of high il-lumination levels or with high-brightness lamps. Fluorescentfixtures might also require crosswise baffles or louvers if in-spection personnel view the lamps lengthwise. At low mountingheights, well-shielded, narrow-beam luminaires, particularly HID,may produce puddles of light at the viewing task level. If widerbeamspread and better uniformity is obtained by reducing shield-ing, the visible bare lamp becomes glaring. The following recom-mendations are provided for avoiding this problem:

(1) Low Mountinq Heiqhts. Install HID luminaires thathave been designed for low mounting heights. These have largediameter reflectors and refractors that provide the widespreadbeam. Because the light from the lamp is spread over the refrac-tor's much larger areas, it in effect becomes the light source.Therefore, the brightness is diluted and reduced to tolerablelevels. Brightness will vary with the lamp's output and the sizeof the refractor.

(2) Narrow-Beam Luminaires. Use more of the same nar-row-beam luminaires, but with lower-wattage lamps and closerspacing. Properly selected, there will be both acceptable over-lap and reduced direct glare. Fluorescent lamps, even thoughthey are inherently lower in brightness than HID lamps, shouldhave deep reflectors and lateral baffles.

Page 76Chap 3

Par 301

g/14/97 AC 43-204

FIGURE 3-5. EXAMPLE OF LUMINAIRE SHIELDING ANGLE(Courtesy of General Electric Company)

h. Uniformitv of Illumination. Uniformity refers to thevariations in illumination levels that occur at the work plane,typically with the highest level under the luminaire and the low-est in between luminaires. The IES considers illuminance to beuniform if the maximum level is not more than one-sixth above theaverage level; or the minimum, one-sixth below. Uniform horizon-tal illumination is called for in most lighting designs whereseeing tasks require the same levels. Closer spaced luminairesimprove uniformity and ensure continued illumination in the eventone or two luminaires are temporarily extinguished. Using IESrecommended reflectances (see Table 3-5) helps improve uniformityand helps reduce unwanted shadows. Ceilings should be painted aflat white to reduce contrast between fixture and ceiling and toincrease illumination. The key to satisfactory uniform lightingis to observe the fixture manufacturer's recommended maximumspacing-to-mounting-height ratio or a similar guide, the spacingcriterion.


AC 43-204 8/14/97

TABLE 3-5. RECOMMENDED REFLECTANCE VALUES FOR INDUSTRIALLIGHTING

SURFACES REFLECTANCE*(Percent)

Ceilinq 80 to 90

Walls I 40 to 60

Desk and bench tops, machinesand equipment

25 to 45

Floors I not less than 20

(1) Maintaininq Uniformitv. Maintaining uniformity ofillumination between adjacent areas which have significantly dif-ferent visibility and illumination requirements might be wastefulof energy; for example, a storage area adjacent to a machineshop. In such instances, it is prudent to design and apply non-uniform lighting between those areas. It may be accomplished byusing luminaires of different wattage and/or by adjusting thenumber of luminaires per unit area. Local lighting restricted toa small work area is unsatisfactory unless there is sufficientgeneral illumination.

(2) Harsh Shadows. Harsh shadows should be avoided,but some shadow effect may be desirable to accentuate the depthand form of objects. There are a few specific visual tasks whereclearly defined shadows improve visibility and such effectsshould be provided by supplementary lighting equipment arrangedfor the particular task. Figures 3-6 and 3-7 illustrate howshadows can aid or hinder the seeing of details. In the case ofcurved and faceted surfaces which are polished or semipolished,the direction of the lighting is important in controlling high-lights. Some shadow contributes to the identification of form.

Page 78Chap 3

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8/14/97 AC 43-204

FIGURE 3-6. HARSH SHADOWS PRODUCED BY UNIDIRECTIONALILLUMINATION (Left) AND SOFT SHADOWS PRODUCEDBY DIFFUSE ILLUMINATION


A': 43-204 a/14/97

FIGURE 3-7. MULTIPLE SHADOWS (Upper Left) ARE CONFUSING;SINGLE SHADOWS (Center) MAY CONFUSE, BUT CANHELP; DIFFUSED LIGHT (Lower Right) ERASES THESHADOWS

(3) Brishtness. Brightness is the strength of sensa-tion which results from viewing surfaces or spaces from whichlight comes to the eye. This sensation is determined in part byluminance (which can be measured) and in part by conditions ofobservation, such as the state of adaptation of the eye. The eyeresponds to differences in brightness or contrast. Improving thecontrast of the seeing task is the goal of the lighting designer,However, extreme variations in brightness in the surroundingfield of view can make seeing more difficult or even uncomfort-able. The eye becomes tired when the pupil has to adjust con-stantly from light to dark and back again. As recommended by theIES, the ratio of the luminance of the seeing task to the sur-rounding areas for comfortable seeing is shown in Table 3-6.


8/14/97 AC 43-204

TABLE 3-6. RECOMMENDED MAXIMUM LUMINANCE RATIOS FORINDUSTRIAL LIGHTING

Environmental Classification*

A B C

1. Between tasks and ad- 3 to 1 3 to 1 5 to 1jacent darker surroundings

2. Between tasks and ad- 1 to 3 1 to 3 1 to 5jacent lighter surround-ings

3. Between tasks and more 10 to 1 20 to 1 +remote, darker surfaces

4. Between tasks and more 1 to 10 1 to 20 fremote, lighter surfaces

5. Between luminaires 20 to 1 + +(windows, skylights, etc.)and surfaces adjacent tothem

6. Anywhere within normal 40 to 1 + +field of view

i. Color. Accurate color identification is required formany visual inspection tasks of aircraft and related articles(color-coded electronic wiring and tubing, paint, penetrant andmagnetic particle inspection indications, corrosion, safetysigns, etc.). The inspectors' reaction to various colors and howthey feel about the area can also be important. Most character-istics of a light source can be analyzed objectively; however,color and color-rendering properties are much more subjective.Additional information on color, is provided by the IES in itshandbooks on lighting.

(1) Chromaticity. Chromaticity or color temperature(whiteness) of a light source sets the tone of the space: warm(yellow, pink) or cool (blue, green). It is measured in Kelvins(K) . The warmer the appearance, the lower the number; the higherthe number, the bluer or cooler the color. Figure 3-8 shows theapproximate color temperatures in Kelvins of several electriclight sources and daylight.


/Jr: 43-204 R/14/97

75OOKnlgn CRI fluorescents

Short arc lenon

SOOOKhigh CR1 fluorescents

cw 6 cwxfluorescent IamDs

WWhWWXlluorescent lamps

tilgh pressure SOdun

Blue northwest sky

Blue sky wfh thanwhite clouds

Blue sky

Average north sky

Unltormovercast sky

Average noon sun

Average mixture ofsun and skyltght

Deluxewhite mercury

Warmdeluxe mercury

lOO.wattIncandescent lamp

25 wattmandescent lamp

Candle flame

FIGURE 3-8. CORRELATED COLOR TEMPERATURE IN KELVINS OFSEVERAL ELECTRIC LIGHT AND DAYLIGHT SOURCES

(2) Color-Rendering. Another important quality of alight source is its ability to render the color of objects in anatural or familiar way. This is usually expressed in terms of acolor-rendering index, or how well a lamp compares with a refer-ence source of the same color temperature. The higher the num-ber, the more nearly like the reference source. Fluorescentlamps are available in a wide range of color temperatures andcolor-rendering capabilities. When good color-rendering is ex-tremely critical for inspection operations, daylight-simulatinglamps are recommended. High-intensity discharge lamps trade-off,


8/14/97 AC 43-204

color-rendering for high efficiency and render colors in the goodto poor range, however, metal halide lamps are the preferred HIDsource where color-rendering is important. Additional informa-tion on light source color-rendering is provided by the IES inits handbooks on lighting and in technical literature availablefrom manufacturers of light sources.

(3) Illuminance Levels. The lighting recommendations inTable 3-1 and Table 3-4 provide a guide for efficient visual per-formance rather than for safety alone; therefore, they are not tobe interpreted as requirements for regulatory minimum illuminancelevels.

j. Tvwes of Lightina Eauioment. The manner in which lightis controlled by the lighting equipment governs to a large extentthe important effects of glare, shadows, distribution, and diffu-sion. Luminaires are classified in accordance with the way inwhich they control the light. Figure 3-9 gives the standard In-ternational Commission on Illumination (CIE) classifications forinterior lighting equipment.

DIRECT SEMI-DIRECT GENERAL, DIFFUSE

40-60%40-608

DIRECT-INDIRECT SEMI-INDIRECT INDIRECT

FIGURE 3-9. INTERNATIONAL COMMISSION ON ILLUMINATION LUMINAIRECLASSIFICATIONS FOR GENERAL LIGHTING

(1) kiahti,ng Aoglications. Most aircraft maintenancelighting applications call for either direct or semi-direct typesof illumination. Industrial luminaires for fluorescent, high-intensity discharge and incandescent filament lamps are availablewith upward light components which contribute to visual comfortby balance of luminances between luminaires and their back-


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grounds. Figure 3-10 shows some typical lamp and fixture lightdistribution curves. Luminaires also require adequate shieldingfor visual comfort (see Figure 3-5). The shielding angle is par-ticularly important for higher luminance sources. Good environ-mental luminance relationships can also often be achieved withtotally direct lighting if the illuminances and room surface re-flectances are high.

HID HID FLUORESCENT HID

LAMP AND FIXTURE TYPE

07

SPACING-TO-MOUNTING-HEIGHT RATIO

1.0 1.3 1.9

FIGURE 3-10. TYPICAL LAMP AND FIXTURE LIGHT DISTRIBUTION CURVES(Courtesy of General Electric Company)

Luminaires with upward components of light are preferred for mostareas because an illuminated ceiling or upper structure reducesluminance ratios between luminaires and the background. The up-ward light reduces the dungeon effect of totally direct lightingand creates a more comfortable and more cheerful environment asshown in Figure 3-11. It shows the importance of a white ceilingin an industrial facility under construction. Note the improvedvisual environment in the right bay (where the painters have fin-ished the ceiling) compared with that in the left bay (as yet,unpainted). The illuminance in the right bay is also substan-tially higher.


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FIGURE 3-11. ILLUSTRATION OF THE IMPORTANCE OF A WHITE CEILINGFOR IMPROVING THE VISUAL ENVIRONMENT OF AN INDUSTRIALFACILITY(Courtesy of General Electric Company)

(2) Luminaire Ton Openings. Top openings in luminairesgenerally minimize dirt collection on the reflector and lamp byallowing an air draft path to move dirt particles upward andthrough the luminaire to the outer air. Therefore, ventilatedtypes of luminaires have proven their ability to minimize mainte-nance of fluorescent, high-intensity discharge, and incandescentfilament types of luminaires. Gasketed dust-tight luminaires arealso effective in preventing dirt collection on reflector andlamp surfaces.

H z r (3) LHiah HTid,ithy;; Corrosive Atmosohere and Classifieda a dousl ocatlo Lia t q The National Fire Protection As-

sociation (NFPA) is phasing out the word "Hazardous" for the word"Classified."

l Nonclassified Areas. Enclosed gasketed luminairesare used in nonclassified areas where atmospherescontain nonflammable dusts and vapors or excessivedust. Enclosures protect the interior of the lu-minaire from conditions prevailing in the area.Severe corrosive conditions necessitate knowledgeof the atmospheric content to permit selection ofproper material for the luminaire.


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l Classified Areas. Classified locations are areaswhere atmospheres contain inflammable dusts, va-pars, or gases in explosive concentrations. Theyare grouped by the National Electrical Code on thebasis of their hazardous characteristics, and allelectrical equipment should be approved for use inspecific classes and groups. Luminaires areavailable, specifically designed to operate inthese areas, which are noted in Article 500 of theNational Electrical Code as Class I, Class II, andClass III locations. Luminaires used in these ar-eas are designated as: explosion-proof, dust-tight, dust-proof, and enclosed and gasketed.

(4) Other Factors. In selecting industrial lightingequipment, the following other factors lead to more comfortablelighting installations:

0 Light-colored finishes on the outside of lumi-naires to reduce luminance ratios between the out-side of the luminaire and the inner reflectingsurface and light source.

l Higher mounting heights to raise luminaires out ofthe normal field of view.

0 Better shielding of the light source by deeper re-flectors, cross baffles, or louvers. This is par-ticularly important with high-wattage incandescentfilament or high-intensity discharge sources andthe higher output fluorescent lamps.

l Selecting light control material, such as mirroredor nonmirrored aluminum, prismatic configuredglass, or plastic that can limit the luminaire lu-minance in the shielded zone.

k. Supplementarv Lishtinq. Difficult seeing tasks often re-quire a specific amount or quality of lighting which cannot read-ily be obtained by general lighting methods. Supplementary lumi-naires are often used to solve such problems by providing higherilluminances for small or restricted areas. Supplementary lumi-naires are also used to furnish a certain luminance, color, or topermit special aiming or positioning of light sources to produceor avoid highlights or shadows to best portray the details of thetask. Figure 3-12 shows examples of placement of supplementaryluminaires.


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0 b dExamples of placement of supplemkntary luminaires: a. Lumlnaire located lo pkent veil-

Ing reflections and reflected glare: reflected light does not coincide with angle of view. b. Reflectedlight coincides with angle of view. c. Low-angle lighting to emphasize surface irregularities. d. Large-area surface source and pattern are reflected toward the eye. e. Translllumination from diffusesource.

FIGURE 3-12. EXAMPLES OF PLACEMENT OF SUPPLEMENTARY LUMINAIRES

(1) Nature of Visual Task. Before supplementary light-ing can be specified, it is necessary to recognize the exact na-ture of the visual task and to understand its light reflecting ortransmitting characteristics. An improvement in the visibilityof the task will depend upon one or more of the four fundamentalvisibility factors: luminance, contrast, size, and time. There-fore, in analyzing a visual task, it may be found that seeingdifficulty is caused by insufficient luminance, poor contrast(veiling reflections), small size, or that the task motion is toofast for existing seeing conditions.

(2) Plannina of Suoolementarv Liahtinq. The planning ofsupplementary lighting also entails consideration of the visualcomfort of both those workers who benefit directly and those whoare in the immediate area. Supplementary equipment should becarefully shielded to prevent glare for the users and their asso-ciates. Luminance ratios should be carefully controlled. Ratiosbetween task and immediate surroundings should be limited as rec-ommended in Table 3-5. To attain these limits it is necessary tocoordinate the placement of supplementary and general lighting.

(3) Luminaires for Suoplementarv Liahtinq. The IES di-vides supplementary lighting units into five major types accord-ing to candlepower distribution and luminance as follows:

l Type S-I-Directional: Includes all concentratingunits. Examples are a reflector spot lamp orunits employing concentrating reflectors orlenses. Also included in the group are concen-trating longitudinal units, such as a well-shielded fluorescent lamp in a concentrating re-flector.

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l Type S-II-Spread, High Luminance: Includes small-area sources, such as incandescent or high-intensity discharge. An open-bottom, deep-bowldiffusing reflector with a high-intensity dis-charge lamp is an example of this type.

0 Type S-III-Spread, Moderate Luminance: Includesall fluorescent units having a variation in lumi-nance greater than two-to-one.

0 Type S-IV, Uniform Luminance: Includes all unitshaving less than two-to-one variation of lumi-nance. Usually this luminance is less than 640candelas per square foot. An example of this typeis an arrangement of lamps behind a diffusingpanel.

a Type S-V, Uniform Luminance With Pattern: A lumi-naire similar to Type S-IV, except that a patternof stripes or lines is superimposed.

1. Portable Luminaires. Whenever possible, supplementaryluminaires should be permanently mounted in the location to pro-duce the best lighting effect. Adjustable arms and swivels willoften adapt the luminaires to required flexibility. Portableequipment (see Table 3-71, however, can be used to good advantagewhere it should be moved in and around movable machines or ob-jects, such as in airplanes, or where internal surfaces should beviewed. The luminaires should be mechanically and electricallyrugged to withstand possible rough handling. Lamps should beguarded and of the rough-service type. Guards or other meansshould protect the user from excessive heat. Precautions shouldbe taken to prevent electrical shock. Cords should be rugged andinsulation should conform to environmental requirements.

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TABLE 3-7. TYPICAL PORTABLE LUMINAIRES FOR SUPPLEMENTARYLIGHTING (Sheet 1 of 7)(Courtesy of McMaster-Carr Supply Company)

ADJUSTABLE ARM LIGHTSa. Gooseneck Lights. These lights have anadjustable gooseneck and are available withhigh-intensity or standard incandescentlamps. They are also available with mag-netic base, table base, C-clamp mount, andexplosion-proof housings. They operate on120V AC.

b. Floating Arm Lights. These lights areavailable with high-intensity fluorescentor standard incandescent lamps and have afloating arm that is adjustable by lightlytouching with a finger. They are alsoavailable with magnetic base, caster base,weighted base, table base, universal mount,and waterproof or explosion-proof housings.They operate on 120V AC.

C . Adjustable High-Intensity Lights. Thishas a five-position switch that providesvarying light intensities. The arm has an18-inch reach and swivels 360° horizontallyand vertically, eliminating wire twist. Itoperates on 120V AC.

d. Clip-On Lights. These lights areavailable with high intensity or standardincandescent lamps and have a spring-loadedclip to attach practically anywhere.Lights have an adjustable shade to allowdirecting of light beam. They operate on120V AC.

‘\PORTABLE UTILITY LIGHTSa . Caddy-Mounted and Tripod-Base Lights.Caddy-mounted and tripod-base lights areavailable with standard incandescent, fluo-rescent and high-intensity lamps. They op-erate on 120V AC.

Chap 3Par 301 Page a9

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PORTABLE UTILITY LIGHTS (Continued)b. Self-Powered Flood Lights. Self-powered lights are available with gasolineor diesel engines and metal malide or high-pressure sodium lamps. They have a tele-scoping base that is adjusted with a winchand two semi-pneumatic tires. They areavailable with 120- and/or 240-V AC out-lets.

C . High Pressure Sodium Light Cart. Thelight cart produces high-intensity lightingwith a wide-angle beam. The light has atempered glass lens with a wire guard andthe cart has two lo-inch wheels and aheavy-gauge steel frame with a handle foreasy portability. The cart operates on120V AC.

d. Polygon Quartz Halogen Floodlights. Apolygon-shaped frame can be positioned onany of five sides to aim the light beamwhere it is needed. A halogen lamp is sus-pended between springs for maximum impactand vibration resistance. It operates on120V AC and is UL listed for wet locationsinside and outdoors.

e. High-Intensity Floodlights. Theselights have up to 500 watts of high-intensity illumination in rugged easy tocarry units with fixed or bolted-downswivel base. They operate on 120V AC.

f. Explosive-Proof Floodlight. Thisfloodlight has a cast aluminum housing witha heat and impact-resistant glass lens.The light moves 135" vertically in a yokeand the base swivels 360" and can be bolteddown, It uses incandescent medium-base spotor flood lamps and also accepts reflectorspot or flood lamps. It operates on amaximum of 600V AC and it is UL standard844 listed Class I Groups C and D for 150-watt lamps and Class I, Group B for 300-watt lamps.


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PORTABLE UTILITY LIGHTS (Continued)g. Corrosion-Resistant Floodlights. ThisFloodlight is suitable for use in damp,corrosive conditions. The fixture has aprotective wire guard, a locking base, anda plastic carrying handle. It operates on120V AC and UL listed.

INCANDESCENT TROUBLE LIGHTSa. General-Purpose Trouble Light. Thesegeneral purpose heavy duty lights use 100-watt incandescent lamps. They operate on r-120V AC, meet OSHA specifications and arr.UL listed.

b. Vapor-Proof Trouble Lights. Theselights are available with a tempered glassor plastic globe that screws into the han-dle to form a vapor-proof seal. They use aloo-watt lamp and operate on 120V AC. Theyare UL listed for enclosed and gasketedfixtures and meet OSHA and National Elec-trical Code (NEC) requirements.

C . Flood and Spot Trouble Light. Thislight uses a flood or spot lamp and has awelded metal guard. This trouble light op-erates on 120V AC, meets OSHA specifica-tions, is UL listed and CSA approved.

d. Magnetic Base Trouble Lights . Thesetrouble lights can be hung by a swivel hookor attached to a ferrous surface with a -:L dmagnet built into the handle base. Theyoperate on 120V AC, use a 75-watt bulb and +.are UL listed. I

e. Hazardous Location Trouble Light. Thistrouble light is spark and weather resis-tant with an aluminum guard and swivelhook. It operates on 120 volts AC. It isUL listed for Standard A21 incandescentlamps up to 100 watts and Class II, Group Gusing a 75-watt A21 lamp.

f. Coiled Cord Trouble Light. This trou-ble light has a coiled cord that resistskinks and knots. The 75-watt light oper-ated on 125V AC. meets OSHA specificationsfor general use and is UL listed.


AC 43-204 8/14/97


INCANDESCENT TROUBLE LIGHTS (Continued)

g. Trim-Line Nonconductive Trouble Light.This light is completely insulated andwon't spark. The light has a flexible,oilproof rubber handle and a tubular nylonguard. The light uses a 7C7 7-watt incan-descent lamp and operates on 120V AC.FLUORESCENT TROUBLE LIGHTSa. Watertight Trouble Lights. Theselights have a butyrate shield and neoprenerubber end cap and handle seal to keep outwater and dampness. They have hinged hookson the end cap and handle that allow themto be easily positioned in the work area.They are available with 20-watt or 40-wattT-12 fluorescent lamps, operate on 120-V ACand are FM approved.

b. Coiled Cord Trouble Light. This smalllight slips into hard-to-reach, hard-to-light places. It has a coiled tangle re-sistant cord that extends up to 13 feet. Abutyrate shield protects the lamp from di-rect contact. It is available with 6-wattand R-watt T-5 fluorescent lamps. It oper-ates on 120V AC and is FM approved.

C . Magnetic Base trouble Light. This _. ,.fluorescent light can be stuck to ferrous .- ,surfaces and has an arm and adjustablebracket for quick secure positioning. Ithas an 8-watt lamp protected by a shatter- ,proof plastic tube. It operates on 120V ACand is UL listed.

d. Compact Trouble Light. The 4-wattmodel has no exposed metal beyond the bal-last; 8-watt model has a grounded metal re-flector. It is available with a magneticholder. Lights come with an 18-foot SJcord and plug. The diameter is 1 5/16inches and the length is from 10 inches (4watt) to 15 inches (8 watt). It operateson 120V AC.


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FLUORESCENT TROUBLE LIGHTS (Continued)e. Cordless Rechargeable Trouble Light.This light provides the convenience of go-ing anywhere without the hassle of an elec-trical cord. The light operates for abouttwo hours before needing a recharge and canbe recharged in three hours. It had a 6-watt 3.6 halogen lamp, protected by astainless steel wire guard. The body ismade of durable antishock plastic. Overalllength is about 14 inches. Lights comewith three 1.2V rechargeable nickel cadmiumbatteries with a rated life of 8 years. Itis available for use with 120V AC or 12V DCand comes with a battery charger. It is ULlisted.

f. Compact Twin-Tube Trouble Light. Thelight has a 13-watt double tube fluorescentlamp to provide twice the illumination ofother lights of the same size. It has arubber handle and end cap and impact resis-tant plastic tube shield with built-in re-flector. The overall size is 14 incheslong by 2 9/16 inch diameter. It operateson 120V AC and is UL listed and CSA certi-fied.

g. Hazardous Location All-Purpose TroubleLight. This light has a non-sparking allaluminum body with annealed glass lampshield and built-in reflector. The lamp isprotected by shock absorbers and an alumi-num guard. The light is 27 inches long by3 l/4 inch diameter with a 15-watt T-8lamp. It meets National Electrical CodeClass I, Div. 1 and 2, Group D; Class II,Div. 1 and 2, Groups E, F, and G; ClassIII, Div. 1 and 2. The cord, ballast, andlamp unit are FM approved.

h. Hazardous Location Compact Twin-TubeTrouble Light. The light has bumper guardsand end caps to protect against damage fromfalling objects, bumping, and dropping.The annealed glass globe is protected by analuminum guard. It is 14 3/4 inches longby 3 l/2 inch diameter and comes with a16/3 SO cord and 13-watt lamp. It operateson 120V AC, is FM approved, and meets Na-tional Electrical Code Class I, Div. 1,Groups C and D; Class II, Div. 1, Groups E.F. and G; and Class III, Div. 1.


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FIBBER-OPTIC ILLUMINATORSa. Quartz Halogen Fiber-Optic Illuminator. The illuminator is used to pro-duce a high-intensity light beam from the tip of fibber optic bundles tolight hard-to-reach places. The light is cold after it passes through a fi-ber-optic light guide, which keeps heat away from the point of inspection.The illuminator is equipped with a basic 0.625 inch opening with reducerbushings provided for adaptability to various other lights guides. It has avariable intensity control with preset divisions to allow for repetitivepresettings. The unit operates on 110-V, 60-Hertz AC, 2 amps. The lamp is150 watt, 3350" Kelvin, 21V. Fiber-optic guides and accessories are nor-mally ordered separately.

b . Xenon Fiber-Optic Illuminator. This illuminator is twice the brightnessof the above quartz halogen unit. It is meant for applications where an ul-tra-high intensity light source is necessary such as long borescopes thatuse fiber-optic illumination or for illuminating light absorbing materials.The unit operates on llOV, 50/60-hertz AC, 6.2 amps. The lamp is a 300watt, 6000" Kelvin, 35 to 5OV DC. Fiber-optic accessories are normally or-dered separately.FIBBER-OPTIC LIGHT GUIDESa . Flexible Light Guides. These light guides are made to be used with fi-ber-optic illuminators. These light guides are flexible and will not sup-port themselves. They are generally used in applications where the lightguide has to be fastened to a part that is movable or they are used with alight guide stand.

b. Light Guide Stand. A light guide stand allows a flexible fiber-opticlight to be positioned where it is needed and also has an adjustable lensthat projects a clear circle of light that can be adjusted from a large areato an intense spot. The stand has 6 l/4-inch vertical travel and 2-inchhorizontal travel at the base, and 5 l/2-inch travel at the lens barrel. Italso features 360" vertical and horizontal rotation.

C . Free-Standing Light Guides. These light guides are made to be used withfiber-optic illuminators and are adjustable at any angle to the workpiece.They can be used as secondary lighting to built-in illumination systemswhere the primary light source is insufficient due to long working distancesor light absorbing workpieces. They are available in single or doublestyles.ILLUMINATION ACCESSORIESa. Ring Illuminators. Ring illuminators are made to be used with fiber-optic illuminators. They provide a circle of light over 360" leaving noshadow pockets, which is not possible with other illumination systems. Thering illuminator can be used as the prime light source for measuring micro-scopes, monocular, or Sterno-viewing microscopes. or as a secondary lightsource for profile projectors, 35-mm cameras or closed-circuit TV systems.

b . Micro-Probe Illumination. These illumination systems are used with fi-ber-optic illuminators and are used in illuminating ultra-small holes andcavities that pose special viewing problems. Available probe diameter are0.032 and 0.120 inch.

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ILLUMINATION ACCESSORIES (Continued)C . Co-Axial Illuminator.illuminators.

A co-axial illuminator is used with fiber-opticIt can illuminate the workpiece 10 to 12 inches and further

from the lens system. It is used where the workpiece needs illuminationwhere a deep cavity is involved that the present ring illuminators or sepa-rate fiber-optic bundles cannot illuminate properly as they are off the op-tical axis. The unit is used for machine vision video applications, opticalcomparators as well as microscope usage provided that there is sufficientmicroscope working distances.

d. Back Light Illumination System. The illuminator is used with fiber-optic illuminators. It illuminates an area of 3 square inches and can beswitched from bright field to dark field by a simple control knob on theside of the unit. It can be used as an inspection tool for electronicswhere dark field illumination is desired and it can be used as backgroundillumination for various microscopes and video applications.

m. Flashlishts. Flashlights used for aircraft inspectionshould be suitable for industrial use and, where applicable,safety approved by the Underwriters Laboratory or equivalentagency as suitable for use in hazardous atmospheres.Specification MIL-F-3747E, Flashlights:

MilitaryPlastic Case, Tubular

(Regular, Explosion-Proof, Explosion-Proof Heat Resistant, Traf-fic Directing, and Inspection-Light) provides requirements forflashlights suitable for use in aircraft inspection. However, atthe present time, the flashlights covered by this specificationuse standard incandescent lamps, and there are no standardizedperformance tests for flashlights with the brighter bulbs(Krypton, Halogen and Xenon). Each flashlight manufacturer cur-rently develops its own tests and provides information on itsproducts in its advertising literature. Therefore, when select-ing a flashlight for use in visual inspection, it is sometimesdifficult to directly compare products. The following character-istics should be considered when selecting a flashlight: foot-candle rating, explosive atmosphere rating, beam spread(adjustable, spot, or flood), efficiency (battery usage rate),brightness after extended use, rechargeable or standard batter-ies, if rechargeable, how many hours of continuous use and howlong for recharging. If possible, it would be best to take itapart and inspect for quality of construction and to use theflashlight as it would be used in the field. Inspection flash-lights are available in several different bulb brightness levels:a. Standard incandescent for long battery life; b. Krypton for 70percent more light than standard bulbs; c. Halogen for up to 100percent more light than standard bulbs; and d. Xenon for over 100percent more light than standard bulbs. Table 3-8 shows some ofthe typical types of inspection lights that are available.


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TABLE 3-8. TYPICAL INSPECTION FLASHLIGHTS (Sheet 1 of 5)(Courtesy of McMaster-Carr Supply Company)

a. Ribbed-Grip Flashlight. This flash-light has a ribbed-grip and a high-impact thermoplastic body that resistsoil, grease, chemicals, corrosion. andshock. It is available with standardfilament bulbs or Krypton bulbs. It isexplosion-proof only with the standardbulb and uses 2 or 3 D-cell batteries.Underwriter laboratories (UL) listedClass I Groups C and D (hazardous vaporsand gasses), and Class II Group G, MineSafety and Health Association (MSHA) ap-proved. The three D-cell model meetsAmerican Society for Testing and Materi-als (ASTM) F1014-86 Type III.

b. Explosive Atmosphere Flashlight.This flashlight is suitable for use inan explosive atmosphere and has a high-impact ABS resin body. It uses Xenonbulbs and 3 or 4 C-cell batteries. Thethree cell model has a pocket clip,hanging ring, and wrist lanyard. Thefour cell model features a backup safetyswitch and adjustable beam for spot toflood. Factory Mutual (FM) and MineSafety and Health Association (MSHA) ap-proved, Class I Groups A, B, C, and D.Canadian Standards Association (CSA)certified.

C . Exwlosive Atmosphere Penlight. Thisflashlight has a polycarbonate resinbody and pocket clip. It is FM ap-proved. Class I Groups A, B, C, and D.Class II Group G. Class III Div. 1 and2. CSA certified.

d. Flexible Light Tool Kit. This lighttool kit includes: penlight with exten-sion mirror l/8-inch-diameter by lo-inchflexible shaft six-inch handle and re-covery magnet.


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e. Right Angle Explosive AtmosphereFlashlight. A two D-cell model withstandard bulb has a waterproof ABS plastic body and three-position switch. Itis UL listed, Class I Groups C, and D,and MSHA approved. A rechargeable modewith halogen bulb has a waterproof highimpact nylon housing with o-ring seals.It is FM approved for use in hazardouslocations.

f. Flexible Krypton Inspection Light.This light contains a krypton bulb thatproduces a lO,OOO-candlepower beam. Thelamp diameter is 3/16 inch. The flash-light is made of a brass alloy and has a15-inch-long flexible shaft that bendsand keeps its shape. It uses three AAbatteries.

g. Flexible Probe Flashlight. Thisflashlight stores a lo-inch-long metalprobe in the body which snaps out forinspecting tight areas. The body isplastic and has a metal hanging ring.It uses two D batteries and a number PR-2 (standard) bulb.

n. Pocket Flex Inspection Lights.These lights can be clipped to a nearbyspot leaving both hands free while workis accomplished. Flexible cables bendand hold their shape. Cases are plas-tic.

. A mini-flex light has a head thatfits through 13/16-inch-diameteropenings. Length is 9.8 inches. Ituses two AA batteries and a MB22NE(standard) bulb.

. An extra power flex light fitsthrough 7/E-inch-diameter openings.Length is 7.5 inches. It uses threeAA batteries and M838G3E bulb.

An extra reach flex light has a 5/8-inch-diameter bulb. Flexible cable is 8inches long. It uses two AAA batteriesand a E30111 bulb.


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i. Skinny Probe Inspection Light. Thislight has 44-inch-long flexible cableand the lamp head can pass through a'i/j:! inch-diameter opening. The longcable lets you lower the bulb into deepareas and put the flashlight case inyour pocket while working. The 3/16-inch-diameter bulb is mounted on the endof ri riqid lo-inch-lonq stem. The unitis impact rcsist.ant, wClt-crproof andwithstands most chemic.dls. It usesthree D batteries and C1 number 187(standard) bulb.

j. Explosion-Proof Inspection Light.This explosion-proof flashlight has a14-inch rigid brass or flexible stemthat lets you examine fuel tanks andot.her fldrnmable liquid containers. Ituses three D batteries and a number 13(st,lndard) bulb.

k. Porta-Power Flex Lights. These in-spection lights have a black anodizedaluminum case with sliding on-offswitch. They focus with a twist of thelens head for pinout or- broad beam illu-mination and they are powered by two Dbatteries; the lamp hcadd fits through a21/32-inch openinq; t-hey use <A number 14(:;tandard) bulb; and they drc' availablewith flexible cable lengths of 9, 18,and 36 inches. A combination unit isavailable that has a 6-inch riqid shattand a g-inch flexible cable.

1. inspection Light Accessories. Ad-justable illuminating mirrors and magni-fiers are available for some model in-spection lights. The glass mirror isI l/4 inch diameter, has a stainless;t.eel back and nickel plated brass ex--cn:;ion arm. Overall length is 4inc.hcas _ The illuminating magnifier has1 :;t r-<light line viewing 6X lens. it is1 l/Z ir1c.h tii,lmeter with <I polished opm- ical ql;~:;:; lc!ns.

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m. Illuminating and Magnifying Inspec-tion Kit. All parts of this kit are in-terchangeable, interlocking and chromeplated. It uses two D batteries and al/R-inch and l/4-inch-diameter bulb.The kit includes 0.1 inch and 0.3 inchdiameter rigid probes in lengths from 3to 14 l/4 inches, a 0.3-inch-diameter by14 l/4-inch-long flexible probe, an 8Xilluminated magnifier; a 10X duplex mag-nifier, and adjustable mirror for use onthe rigid probes, 0.9 and 1.5-inch-diameter short stem mirrors; recoverymagnet and hook; and accessory handle.

n. Mini Bench Lights. These lights aremade to use at the workbench. Lamps canenter a 21/32-inch opening. Each lighthas a nonsparking aluminum case with aflexible cable (6, 9, or 12 inches long)that bends and stays in position. Theelectric bench light comes with a 2.5-volt transformer and switch for llO-voltAC outlet. The 5/E-inch-diameter headhas a focusing ring for a circle oflight or pinpoint beam. The case isshockproof and it uses a number 13(standard) bulb. The battery operatedbench light uses two AA batteries and anumber 222 (standard) bulb.

0 . Light Bender Inspection Kit. Thiskit uses a penlight with a Lucite rodand mirror to see around corners. Ituses one or two AA batteries. The kitincludes: one and two cell penlight; 6and 2 l/2-inch-long straight Luciterods; clip-on mirror; 4-inch curved Lu-cite rod; and soft plastic case.

P- Extended Reach Inspection Kit. Thiskit has up to five-foot reach inter-changeable probes, each with its own at--tached light. The kit includes; a five-foot flexible cable probe; a 12-inchstraight and flexible probe; a five-inchangle probe and two-inch bendable probe;a 1.2-inch and 0.6-inch diameter mirror;a 22-nun-diameter mirror; magnifyinglens; recovery magnet and hook; shroudedand side aperture lamps; probe adapter;and case.


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9. Twist-Beam Penlights. These flash-lights use standard two M-cell batter-ies and the beam adjusts from spot toflood.

302. LIGHTING SYSTEMS. Lighting systems are often classifiedin accordance with their layout or location with respect to thevisual task or object lighted (general lighting, localized gen-eral lighting, local [supplementary] lighting, and task-ambientlighting). They are also classified in accordance with the CIEtype of luminaire used (direct, semi-direct, general diffuse[direct-indirect], semi-indirect, and indirect), as shown in Fig-ure 3-9. Luminaires for general lighting are classified by theCIE in accordance with the percentages of total luminaire outputemitted above and below horizontal. The light distributioncurves may take many forms within the limits of upward and down-ward distribution, depending on the type of light source and thedesign of the luminaire. Light distribution curves for sometypical lamp and fixture types that might be used for visual in-spection tasks of aircraft and related articles are shown in Fig-ure 3-10. Light distribution curves may be available in techni-cal literature available from manufacturers of light sources.Horizontal tasks and high, narrow spaces can be most efficientlylighted with fixtures that concentrate most of their lightstraight down. Such fixtures usually appear to be quite comfort-able. However, tasks that are more vertical require light comingfrom the luminaire at relatively high angles. Luminaires emit-ting light at high angles are apt to be excessively bright anduncomfortable unless carefully designed. Broad-distribution lu-minaires are more effective in letting light out of the unit thannarrow-distribution ones, but are less effective in getting lightto the horizontal work plane in high-bay, narrow spaces sincewalls absorb a greater portion of the light. Manufacturers gen-erally provide a coefficient of utilization table, which is theratio between the amount of light or lumens reaching the horizon-tal task to the lumens generated within the luminaire. The manu-facturer's recommended spacing-to-height ratio (or spacing crite-rion) indicates whether the output of the fixture is broad ornarrow.

a. General Liahtinq. General lighting systems provide anapproximately uniform illuminance on the work plane over the en-tire work area. The luminaires are usually arranged in a symmet-rical plan fitted into the physical characteristics of the areaand therefore blend well with the room architecture. They arerelatively simple to install and require no coordination withfurniture or machinery that may not be in place at the time of


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installation. Perhaps the greatest advantage of general lightingsystems is that they permit complete flexibility in task loca-tion.

b. Localized General Lishtinq. A localized general lightingsystem consists of a functional arrangement of luminaires withrespect to the visual task or work areas.mination for the entire room area.

It also provides illu-Such a lighting system re-

quires special coordination in installation and careful consid-eration to ensure adequate general lighting for the room. Thissystem has the advantages of better use of the light on the workarea and the opportunity to locate the luminaires so that annoy-ing shadows, direct glare,or minimized.

and veiling reflections are prevented

C . Local Lishtinq. A local lighting system provides light-ing only over a relatively small area occupied by the task andits immediate surroundings. The illumination may be from lumi-naires mounted near the task or from remote spotlights. Theseare an economical means of providing higher illuminances over asmall area, and it usually permits some adjustment of the light-ing to suit the requirements of the individual.ments may, however,

Improper adjust-cause annoying glare for nearby workers. Lo-

cal lighting by itself is seldom desirable.changes in adaptation,

To prevent excessivelocal lighting should be used in conjunc-

tion with general lighting that is at least 20 to 30 percent ofthe local lighting level; it then becomes supplementary lighting.

d. Task-Ambient Lishtinq. Task-ambient lighting is a typeof lighting arrangement where the lighting is built into the fur-niture in an open plan office layout. Task lights are locatedclose to work areas (as in local lighting above) and are supple-mented by indirect ambient illumination from sources concealed inthe furniture and directed to the ceiling (as in general lightingabove). These systems usually have extensive ceiling areas al-most totally devoid of lighting equipment. Electrical service tothe lighting equipment is often through the floor.

e. Direct Lishtinq. When luminaires direct 90 to 100 per-cent of their output downward, they form a direct lighting sys-tem. The distribution may vary from widespread to highly concen-trated, depending on the reflector material, finish, and contourand on the shielding or control media employed.

(1) Direct Glare Control. Direct lighting units canhave the highest room utilization factor of all types, but thisutilization may be reduced in varying degrees by brightness con-trol media required to minimize direct glare. Direct glare mayalso be reduced by using area units with minimum number of lamps,e.g., a two-foot-wide fluorescent unit with just two lamps.


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(2) Veilins Reflections. Veiling reflections may be ex-cessive unless distribution of light is designed to reduce theeffect.

(3) Reflected Glare and Shadows. Reflected glare andshadows may be problems unless close spacings are employed.Large area units are also advantageous in this respect. High-reflectance room surfaces are particularly important with directlighting to improve the brightness relationships, and higher il-luminances provided by controlled brightness equipment will alsotend to improve the brightness relationships throughout the room.With very concentrated distributions, care should be taken to en-sure adequate wall luminances and illuminances on vertical sur-faces.

(4) Other Forms of Direct Lishtinq. Luminous ceilings,louvered ceilings, and large-area modular lighting elements areforms of direct lighting having characteristics similar to thoseof indirect lighting discussed in later paragraphs. These formsof lighting are frequently used to obtain the higher illumi-nances. Care should be taken to limit the luminance of theshielding medium to 80 candelas per square foot or less to pre-vent direct glare if critical, prolonged seeing is involved. Re-flected glare may be a problem with systems employing cellularlouvers as the shielding medium, since the images of the lightsources above the louvers may be reflected by shiny surfaces atthe work plane.

f. Semi-Direct Lishtinq. The distribution from semi-directunits is predominantly downward (60 to 90 percent), but with asmall upward component to illuminate the ceiling and upper walls.The characteristics are essentially the same as for direct light-ing, except that the upward component will tend to soften shadowsand improve room brightness relationships. Care should be exer-cised with close-to-ceiling mounting of some types to preventoverly bright ceilings directly above the luminaire. The roomutilization factor can approach or even exceed that of well-shielded direct units.

9. General Diffuse Lishting. The lighting system is classi-fied as general diffuse when downward and upward components oflight from luminaires are about equal (each 40 to 60 percent oftotal luminaire output). General diffuse lighting units combinethe characteristics of direct and indirect lighting. The roomutilization factor is somewhat lower than for direct or semi-direct units, but it is still quite good in rooms with high re-flectance surfaces. Brightness relationships throughout the roomare generally good, and shadows from the direct component aresoftened by the upward light reflected from the ceiling.

(1) Direct Glare Control. Excellent direct glare con-trol can be provided by well-shielded units, but short suspen-sions can result in ceiling luminances that exceed the luminaire

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-luminances. Close spacings or layouts that locate units so thatthey are not reflected in the task result in reductions of re-flected glare from the downward component.

(2) Pendant Mountinqs. Luminaires designed to provide ageneral diffuse or direct-indirect distribution when pendantmounted are frequently installed on, or very close to, the ccil-ing. These type mountings change the distribution to direct orsemi-direct since the ceiling acts as a top reflector redirectingthe upward light back through the luminaire. Photometric data,obtained with the luminaire equipped with top reflectors or in-stalled on a simulated ceiling board, should be employed to de-termine the luminaire characteristics for such application condi-tions.

h. Direct-Indirect Liqhtinq. Direct-indirect lighting is aspecial (non-CIE) category within the classification for lumi-naires which emit very little light at angles near the horizon-tal. Since this characteristic results in lower luminances inthe direct glare zone, direct-indirect luminaires are usuallymore suitable than general diffuse luminaires which distributethe light about equally in all directions.

i . Semi-Indirect Lishtinq. Lighting systems which emit 60to 90 percent of their output upward are defined as semi-indirect. The characteristics of semi-indirect lighting aresimilar to those of indirect systems, except that the downwardcomponent usually produces a luminaire luminance that closelymatches that of the ceiling. However, if the downward componentbecomes too great and is not properly controlled, direct or re-flected glare may result. An increased downward component im-proves utilization of light somewhat over that of indirect light-ing. This factor makes somewhat higher illuminances possiblewith fewer semi-indirect luminaires and without excessive ceilingluminance.

j. Liqhtinq for the Cathode Rav Tube (CRT). Cathode raytubes are commonplace, with visual display units appearing on theshop floor with ultrasonic equipment, eddy current equipment,video adapters for borescopes and microscopes, etc. Their typi-cally convex surfaces act like curved mirrors that reflect largeareas of ceiling, walls, windows, and other room surfaces. Ifany of these surfaces are intrinsically bright, such as windowsand fixtures, or are brightly lighted, their reflected imageswill reduce the visibility of the information being processed onthe screen and annoy the operator. The CRT problem could besolved by turning off all the lights and shading the windows;however, this is usually not practical. Many of the screen re-flection problems can be reduced by the following methods:

(1) Screen Orientation. Proper screen orientation orusing hoods or anti-reflection screens or filters.


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(2) Shades. Using blinds, shades, or dark curtains tohelp eliminate window brightness.

(3) Dark Colors. Finishing walls and other verticalsurfaces in darker colors.

(4) Worker Clothing. Equipping operators with darksmocks.

(5) Luminaires. Using luminaires with dark-tintedlenses, deep parabolic baffles, or parabolic wedge louvers tocontrol fixture brightness. Bright lamp images seen in shinysurfaces directly beneath the fixture can be eliminated by layinga thin plastic diffuser on top of the lens or louver.

(6) Indirect Lishtinq. When indirect lighting is usedto correct CRT reflection problems, levels should not exceed 30footcandles; otherwise, vertical surfaces get too bright. Ceil-ing brightness should be uniform with no hot spots. At thislevel, supplementary task lighting often will be required.

(7) Parabolic Lenses. Parabolic lenses can be used toobtain levels up to about 100 footcandles. If higher levels areneeded for specific tasks, supplementary lighting can also beused.

303.-399. RESERVED.

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CHAPTER 4. EQUIPMENT USED IN VISUAL INSPECTION

AC 43-204

400. GENERAI,. The following chapter describes the variousaids to vision used in visual inspection. In general, they con-sist of mirrors, magnifiers, and various schemes for conveyingimages from inaccessible sources to where they may be seen.

a. Insnection Mirrors. Inspection mirrors are used to viewareas that are not in the normal line of sight. Table 4-1 showssome of the typical types of inspection mirrors that are avail-able for inspection of hidden areas.

TABLE 4-1. TYPICAL INSPECTION MIRRORS(Courtesy of McMaster-Carr SupplyCompany) (Sheet 1 of 2)

a . Ball-Joint Telescoping Inspection Mirror.This inspection mirror has tempered springsteel, double ball-joint links to allow mirror(true image or magnifying) to move 360p forviewing in any position. Nonrotating innerhex rods on telescoping models prevent mirrorsfrom swinging out of alignment. Replacementmirrors are available.

b. Spring-Loaded Inspection Mirror. This in-spection mirror has a spring-loaded plunger totilt the mirror 90Q. The mirror is returnedto the straight position by tripping a lockingdevice. Single-handed operation allows in-spection without removing the mirror from thework area.

C . Telescoping Inspection Mirror with Magnet.This inspection mirror can be used to findlost nuts, bolts, and other small parts andthen pick them up with the magnet in the han-dle. the telescoping handle has a doubleball-joint to hold glass mirror at any angle.

d. Electrical Component Inspection Mirror.This inspection mirror is extra thin so it canbe used to inspect under and around smallelectrical components. The go-degree mirrorshave beveled edges to match inspection sur-faces. Handles are spring-mounted.


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TABLE 4-1. TYPICAL INSPECTION MIRRORS(Courtesy of McMaster-Carr SupplyCompany) (Sheet 2 of 2)

e . Electrically Insulated Inspection Mirror.This inspection mirror is electrically insu-lated to prevent dangerous shocks or shortswhen inspecting near sources of electricity.

i. Adjustable Angle tlluminated InspectionMirror. This inspection mirror has a lightand adjustable mirror at the tip that can becontrolled with the thumb.

cl. Magnetic Base Inspection Mirror. This in-spection mirror has magnets in a molded nylonbase that allows mounting in the work area.Two ball joints allow adjustment of the qlassmirror.

h . Long Reach Extension Inspection Mirror.This inspection mirror hds a nonconductinghandle which extends from five to sixteen feetand it has a nine- by nine-inch glass mirrorwith light.

i. Suction Cup Inspection Mirror. This tele-scoping arm inspection mirror attaches withthree suction cups to any hard smooth surface.The telescoping arm can be extended up tothirty inches. The four-inch-diameter un-breakable mirror is true image on one side andmagnified image on the other.

j. Illuminated Inspection Mirror. This pen-light inspection mirror has a Lucite rod thatdirects light on an adjustable plastic framemirror.

b. Simple Maqnifiers. A single converging lens, the sim-plest form of a microscope, is often referred to as a simple mag-nifier. Magnification of a single lens is determined by theequation M = 10/f, where M is the magnification, f is the focallength in inches, and 10 represents the average minimum distanceat which objects can be distinctly seen by the unaided eye. Forexample, using this equation, a lens with a focal length of 5inches has a magnification of 2, or is said to be a two-powerlens (sometime written 2X). Table 4-2 shows some of the typicaltypes of simple magnifiers that are available.


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TABLE 4-2. TYPICAL SIMPLE MAGNIFIERS(Courtesy of McMaster-Carr SupplyCompany)

a. Folding Case Magnifiers. Thesemagnifiers contain single glass oracrylic plastic lenses which can becombined for magnification from 3 to 20power. The lenses swing out whenneeded and the plastic case acts as ahandle. Focal lengths vary from l/2 to2 l/2 inches depending on lens combina-tion.

b. Pocket Magnifiers. These magnifi-ers contain single glass or acrylicplastic lenses mounted in a case thatslides open and locks shut to protectthe lens when placed in the pocket.Overall size is 1 5/R inches by 2 l/4inches. They are available in 3X and5X with focal length of 3.3 inches and2 inches.

c. Round and Rectangular Magnifiers.These magnifiers have a sculpturedplastic handle and lens frame and areavailable with glass or scratch resis-tant acrylic plastic lenses. The glasslenses have 2X magnification, lens di-ameters from 2.75 to 5.32 inches andfocal lengths from 6 to 13 inches. Theacrylic lens have 2.5X to 3X (with a 5Xbifocal insert), lens diameters arefrom 2 inches and focal lengths from 10to 2 inches.

\d. Attached Case Magnifiers. Thesemagnifiers have an all in one case thatprotects the lens and serves as a han-dle. A 2X model has a glass and vinylcase; 3X model has an acrylic lens andplastic case. Lens diameters are 2inches and 1.5 inches and focal lengthsare 5 inches and 2.5 inches.

(1) Workina Distance. The focal length of a simple mag-nifier and its working distance are approximately the same. Forexample, suppose that it is desired to examine a part without re-moving it and the magnifier cannot be placed nearer than 3inches. Therefore, a magnifier with a working distance (focallength) of at least 3 inches is required. From the equation M =10/f, a three-power lens is required.

(2) Field of View. The field of view is the area seenthrough the simple magnifier. The diameter of the field of view


AC 43-204 8/14/97

of a simple magnifier is less than its focal length. Selectionof a magnifier with proper field of view is important. For exam-pie, if a large object is to be examined, the time involved usinga 20-power magnifier (with a field of view slightly greater than3/8 inch) would be prohibitive.

(3) Depth of Field. Depth of field is the term used toindicate the distance a magnifier can be moved toward or awayfrom an object, with the object remaining in good focus. Atother distances the object is out of focus and not sharply de-fined. Depth of field varies with the power of the lens and iscomparatively greater in lower-power magnifiers, decreasing asthe power of the lens increases.

401. MAGNIFYING DEVICES. Some magnifying devices recommendedfor use in conducting visual inspections include: hand-held mag-nifiers with single and multiple lenses jeweler's eye loupes, il-luminated magnifiers, pocket/desk type microscopes, toolmaker'smicroscopes, rigid/flexible borescopes, and video imaging sys-tems. These devices are available with numerous features, suchas 1 to 2000 power, self-contained illumination, adjustable vari-able magnification (zoom), stereo viewing, data storage/ trans-mission, computer generated electronic alignment targets, andmeasuring capability.

a. Selectinq Maqnification Power. Magnification power andfield of view are interrelated, and, in general, as magnificationpower is increased, the field of view is reduced. Therefore, itis important to select a magnification power that will providethe proper field of view for the part being inspected. When in-specting a large area, the time involved could be prohibitive ifhigh power magnification (with a small field of view) is used.Therefore, the recommended procedure is to first use low powermagnification (with a large field of view), mark questionable ar-eas, and then examine marked areas using high power magnifica-tion. The precise relationship between magnification power andfield of view of a product is usually specified by the manufac-turer.

b. Liqht Collectinq Abilitv. The detail observed in a mag-nifier depends on its light collecting ability, which depends onits diameter and focal ratio (focal length divided by diameter).

402. PHOTOGRAPHIC AND VIDEO SYSTEMS. An image on a videomonitor or a photograph allows inspectors to share analysis, de-cisions, knowledge, and skills when making visual inspections.Photographic and video systems are available which attach to theeyepieces of borescopes, fiberscopes, and microscopes for docu-mentation and analysis of visual inspection images. Video sys-tems are also available that have a charge-coupled device (CCD)image sensor at the probe end of the borescope or microscope,which allows wire rather than fiber optic transmission of the im-age.


8/14/97 “IC 43-204. I Ia. Svstem Caoabllltls. Video systems permit video images

to be recorded and stored on print or slide film, video cassetterecorders, or computer disks. Microprocessors can be used todigitize video images for storage on a computer disk, or fortransfer to other sites by modem and telephone lines. Photo-graphic or video recording provides verifiable data for trainingpurposes and for trend monitoring.

b. Tvoical Svstems. Figure 4-1 shows a typical 35-mm cameraand adapter installed on a rigid borescope that has a mountingkit to provide a platform for vibration-free photography. Figure4-2 shows a typical video adapter system for converting a stan-dard flexible or rigid borescope to a video inspection and docu-mentation system. Figure 4-3 shows a block diagram of a typicalvideo inspection, documentation, storage, and transmission sys-tem.

FIGURE 4-1. TYPICAL 35-MM CAMERA AND CAMERA ADAPTER INSTALLATIONON A RIGID BORESCOPE(Courtesy of Olympus Corporation)


A: 43-2048/14/97

FIGURE 4-2. TYPICAL BORESCOPE VIDEO ADAPTER SYSTEM(Courtesy of Optronics EngineeringCorporation)

Page 122

Chap 4Par 402

:lC 43-204

Microscope with a CCD

Digitiztng. Processmg,

FIGURE 4-3. BLOCK DIAGRAM OF A TYPICAL VIDEO INSPECTION SYSTEM

C . Hand-Held Video Microscooe Imaainu Svstem. In some videomicroscope inspection equipment, the camera, lens, and lightingare all integrated into a flexible, hand-held probe that is takento the item to be inspected (see Figure 4-4). A solid-state CCDsensor is located in the end of the camera head, and various


iif: 43-204 8/14/97

lenses can be attached to the camera head to provide the userwith magnifications from 0.7 to 800 power and working distancesfrom contact to 600 mm. The instrument provides a high resolu-tion, full color video image; records the image for later use; isportable; and can be customized for a specific application. Theinstrument is particularly useful in areas where it is difficultto hold a flashlight and mirror while trying to focus a magnify-ing glass. Some typical uses for the hand-held video microscopein aircraft maintenance are inspection of aircraft seat tracksfor cracks (it is a one-hand operation of placing the video mi-croscope head on the tracks and viewing the screen, where previ-ously a mirror and flashlight were required); inspection of com-posite-material helicopter rotor leading edges for delamination/damage; inspection of aircraft turbine honeycomb seal rings fordefects; and inspection of aircraft rear pressure bulkhead, en-gine pylon, spar, and main landing gear aft trunnion for defects.

FIGURE 4-4. SCOPEMAN HAND-HELD VIDEO MICROSCOPE IMAGING SYSTEM(Courtesy of Moritex USA, Inc.1

d. Video Measurina Microscooe. Video measuring microscopes(see Figure 4-5) are also available. They use a high-quality


a/14/97 1C 43-204

zoom microscope (magnification from 8 to 1630 power) with joy-stick control in conjunction with a high-resolution color videoand computer. The SmartScope system contains a set of computer-generated electronic targets and charts for superimposing on thecolor video image to match the feature being measured. A graph-ics model that looks like a blueprint of the part is built bySmartScope software as each measurement is completed. The graph-ics model is stored on a hard disk and can be displayed orprinted at any time. Some examples of the use of video measuringmicroscopes for aircraft maintenance are measurement of hole di-ameter and locations on castings after they have been reworkedand measurement of dimensions of used mechanical parts to deter-mine if they are still serviceable.

FIGURE 4-5. SMARTSCOPE VIDEO MEASURING MICROSCOPE SYSTEM(Courtesy of Optical Gaging Products, Inc.)


403. OPTICAL COMPARATORS. Optical comparators are devices thatproject a magnified silhouette of a small part onto a large pro-jection screen, which is then compared against a magnified out-line drawing of the part being inspected. They are used in air-craft maintenance for assessing parts conformity. Figure 4-6shows a typical schematic of an optical comparator. Optical com-parators are available with numerous options, such as screensizes from 14 to 30 inch diameter, magnifications from 5 to 500power, computerized control of measurement and movement, computerstatistical analysis of data, part programming from blueprint(off-line or pantograph, 0.00005-inch measurement and one minuteof arc resolution), and automatic centerline system for detectionof shadow edges. Parts with recessed contours can also be meas-ured on optical comparators by using a pantograph. One arm ofthe pantograph is a stylus that traces the recessed contour ofthe part, and the other arm carries a follower that is visible inthe light path. As the stylus moves, the follower projects acontour on the screen. Optical comparators typically are used tomeasure threads, gear teeth, hole diameters, distance betweenholes, angles, and tapers. Figure 4-7 shows a typical opticalcomparator. Some examples of the use of an optical comparatorfor aircraft maintenance are measuring dimensions on grindingwheels that are used to rework aircraft turbine blades (if con-tact type measurements were made in this application, the measur-ing tools would be damaged by the grinding wheel abrasive); meas-urement of hole diameter and locations on gearbox castings afterrework; and measurement of radii on used constant-speed driveshafts to verify that the shear sections would meet new part re-quir

/I--------

Screen /

Condensing -\ Reflectinglens -1

-1mirror

Lightsource I

Magnifying (lens , ‘\. \I w-e ;Ibtl.;;;. --L- -III ; II I II II - - - - - - - - - -

Page 126

FIGURE 4-6. SCHEMATIC OF AN OPTICAL COMPARATOR

Chap 4Par 403

8/14/97 '\C43-204

FIGURE 4-7. TYPICAL OPTICAL COMPARATOR(Courtesy of Optical Gaging Products,Inc.)

404. BORESCOPES. A borescope is a long, tubular, precisionoptical instrument, with built-in illumination, designed to allowremote visual inspection of internal surfaces, or otherwise inac-cessible areas. The tube, which can be rigid or flexible with awide variety of lengths and diameters, provides the necessary op-tical connection between the viewing end and an objective lens atthe distant, or distal, tip of the borescope. Rigid and flexibleborescopes are available in different designs for a variety ofstandard applications, and manufacturers also provide custom de-signs for specialized applications. Figure 4-8 shows threetypical designs of borescopes.


a. Borescop-_eUses.~___- Borescopes are used in aircraft/enginemaintenance programs to reduce or eliminate the need for costlyteardowns. Aircraft turbine engines have access ports that arespecifically designed for borescopes. Borescopes are also usedextensively in a variety of aviation maintenance programs to en-sure the airworthiness of difficult-to-reach components.Borescopes typically are used to inspect interiors of hydrauliccylinders and valves for pitting, scoring, porosity, and tool

l'aqc 128Chap 4Par 404

marks; inspect for cracked cylinders in aircraft reciprocatingengines; inspect turbojet engine turbine blades and combustioncans; verify the proper placement and fit of seals, bonds, gas-kets, and subassemblies in difficult-to-reach areas of aircraftand aeronautical equipment; and assess Foreign Object Damage(FOD) in aircraft, airframe, and powerplants. Borescopes mayalso be used to locate and retrieve foreign objects in enginesand airframes.

b. Ootical Desisns. Typical designs for the optical connec-tion between the borescope viewing end and the distal tip are asfollows: rigid tube with a series of relay lenses, flexible orrigid tube with a bundle of optical fibers, and flexible or rigidtube with wiring that carries the image signal from a CCD imagingsensor at the distal tip. These designs can have either fixed oradjustable focusing of the objective lens at the distal tip. Thedistal tip also has prisms and mirrors that define the directionand field of view (Figure 4-9). A fiber-optic light guide withwhite light is generally used in the illumination system, but ul-traviolet light can also be used to inspect surfaces treated withliquid fluorescent penetrant or to inspect for contaminants thatfluoresce. Some videoscopes with long working lengths use light-emitting diodes at the distal tip for illumination.

Atight angle

Clrcumlerence

Forward oblque Retrospectwe

FIGURE 4-9. TYPICAL DIRECTIONS AND FIELD OF VIEW OF RIGIDBORESCOPES (Courtesy of ASM International)

C . Borescooe Selection. Flexible and rigid borescopes areavailable in a wide variety of standard and customized designs,and several factors can influence the selection of a scope for a


AC 43-204 8/14/97

particular application. These factors include focusing and reso-lution, illumination, magnification and field of view, workinglength, direction of view, and environment.

(1) Focusins and Resolution. In general, the opticalquality of a rigid borescope improves as the size of the lensincreases; consequently, a borescope with the largest possiblediameter should be used. If portions of long objects are at dif-ferent planes, the borescope should have sufficient focus adjust-ment to achieve an adequate depth of field. If the borescope hasa fixed focal length, the object will be in focus only at a spe-cific lens-to-object distance. To allow the observation of sur-face detail at a desired size, the optical system of a borescopeshould also provide adequate resolution and image contrast. Ifresolution is adequate, but contrast is lacking, detail cannot beobserved. For fiberscopes, the resolution is dependent on theaccuracy of alignment and the diameter of the fibers in the imagebundle. Smaller diameter fibers provide more resolution and edgecontrast when combined with good geometrical alignment of the fi-bers.

(2) Illumination. The amount of illumination depends onthe diameter of the light guide bundle; therefore, it is desir-able to use the largest diameter possible. The required inten-sity of the light source is determined by the reflectivity of thesurface, the area of surface to be illuminated, and the transmis-sion losses over the length of the scope. Rigid borescopes witha lamp at the distal end provide the greatest amount of illumina-tion over the widest area at working lengths greater than 20feet; however, the heat generated by the light source can damagesome materials. Fiber-optic illumination is usually brighterthan a lamp at the distal end with scope working lengths lessthan 20 feet and is suitable for heat-sensitive applications whenfilters are used to remove infrared wavelengths.

(3) Maqnification and Field of View. Magnification andfield of view are interrelated, and as magnification is in-creased, the field of view is reduced. The precise relationshipbetween magnification and field of view is generally specified bythe product manufacturer. The degree of magnification in a par-ticular application is determined by the field of view and thedistance from the objective lens to the object. The magnifica-tion increases when either the field of view or the lens-to-object distance decreases.

(4) Working Length. The working length can sometimesdictate the use of a particular type of borescope. For example,a rigid borescope with a long working length may be limited bythe need for additional supports. In general, videoscopes allowa longer working length than fiberscopes.

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(5) Direction of View. The selection of a viewing di-rection is influenced by the location of the access port in rela-tion to the object to be observed.eoscopes,

Flexible fiberscopes or vid-because of their articulating tip, are often adequate

with either a side or forward viewing tip. Circumferential orpanoramic heads are designed for the inspection of tubing orother cylindrical parts. A centrally locdted mirror permitsright angle viewing of an area just scanned by the panoramicview. The forward viewing head permits the inspection of thearea directly ahead of the viewing head and is commonly used whenexamining facing walls or the bottoms of blind holes and cavi-ties. Forward-oblique heads bend the viewing direction at an an-gle to the borescope axis,at the end of a bored hole.

permitting the inspection of cornersRetrospective viewing heads bend the

cone of view at a retrospective angle to the borescope axis, pro-viding a view of the area just passed by the advancing borescopeand are especially suited for inspecting the inside corners ofvalve body and actuating cylinder castings.

(6) Environment. Flexible and rigid borescopes can bemanufactured to withstand a variety of environments. Althoughmost borescopes can operate at temperatures from -30 to 150 de-grees F, specially designed borescopes can be used at tempera-tures to 3500 degrees F. Borescopes can also be manufactured foruse in liquid media. Special borescopes are required for use atpressures above ambient and in atmospheres exposed to radiation.Radiation can cause lenses and fiber-optic bundles to turn brown.When a borescope is used in atmospheres exposed to radiation,quartz fiberscopes are generally used. Scopes used in a gaseousenvironment should be made explosion-proof to minimize the poten-tial of an accidental explosion.

d. Rigid Borescopes. Rigid borescopes are generally used inaircraft maintenance applications where there is a straight lineaccess path to the area to be inspected. Some typical uses forrigid borescopes in aircraft maintenance are inspection of land-ing gear actuators and struts for corrosion; cracks and scratcheson bore walls;stringers,

inspection for corrosion and cracks of wingwing attachment fittings, spars, and other aircraft

structural members; inspection of engine cylinder sleeves, pis-tons, and valves for damage; and inspection of aircraft turbinesfor cracks, corrosion, damage by foreign objects, and erosion.Rigid borescope sizes range in lengths from 2 inches to over 100feet and in diameters from 0.035 to 2.75 inches. Magnificationis usually 3 to 4 power, but powers up to 50 are available.are available with fixed and adjustable focus eyepiece.

TheyThe il-

lumination system is either an incandescent lamp located at thedistal end or a light-guide bundle made from optical fibers thatconducts light from an external source. The fiber-optics, light-guide bundle has no electrical contacts at the distal end andproduces cold light to minimize explosion hazards. Rigidborescopes are available with a variety of viewing heads for se-


Aic 43-204 a/14/97

lection according to the application. They generally have a 55-degree field of view although fields of view can range from 10 to90 degrees. The distal tips are generally not interchangeable,but some models, such as the extendible borescopes, can have in-terchangeable distal tips. Some rigid borescopes have the capa-bility to rotate the optical shaft from 120 to 370 degrees forscanning purposes, and others have movable prisms at the tip forlongitudinal scanning.

(1) Basic Desiqn. The rigid borescope typically has aseries of achromatic relay lenses in the optical tube. Theselenses preserve the resolution of the image as it travels fromthe objective lens to the eyepiece. The tube diameter of theseborescopes ranges from 0.035 to 2.75 inches. The illuminationsystem can be either a distal lamp or a light-guide bundle, andthe various features may include rotating optical shaft, variousviewing heads, and adjustable focusing of the objective lens.

(2) Micro-borescopes. Micro-borescopes are small-diameter borescopes having an integral light-guide bundle and aone-piece rod lens for maximum resolution with a minimum diame-ter. Some typical uses for micro-borescopes in aircraft mainte-nance are inspection for damage within fuel nozzles, electroniccomponents, instruments, hydraulic components, castings, andother miniature equipment. The lengths of micro borescopes rangefrom 2 to 32 inches, and the diameters range from 0.020 to 0.125inch. They are available with forward, forward oblique, andright angle views; support stands with micrometer adjustable fix-turing; photo and video adapters; up to 30-power magnification;and fixed or ocular focus. Figure 4-10 shows a typical micro-borescope.

Page 132Chap 4

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AC 43-204

FIGURE 4-10. TYPICAL MICRO-BORESCOPE(Courtesy of Industry Technology,Inc.)

(3) Extendible Borescooes. Extendible borescopes allowthe user to vary the length of the borescope tube by insertingextension tubes. Some typical uses for rigid extendibleborescopes in aircraft maintenance are inspection for damagewithin turbine engine combustion cases and inspection for cracksin aircraft rear pressure bulkheads. Extendible borescopes areavailable with either a fiber-optic light guide or an incandes-cent lamp at the distal end. Extendible borescopes with an inte-gral lamp have a maximum length of about 100 feet. Extendibleborescopes with a light-guide bundle are available with smallertube diameters, but have shorter maximum lengths (approximately30 feet). Extendible borescopes allow one borescope to do thework of several different borescopes. Therefore, when feasiblefor the inspection tasks involved, they can have the advantage ofeconomy, adaptability, and less bulk and weight for easy trans-portation and use over the purchase and use of a differentborescope for each inspection task. Interchangeable viewingheads are available for extendible borescopes. Figure 4-11 showsa typical extendible borescope.


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FIGURE 4-11. TYPICAL EXTENDIBLE BORESCOPE(Courtesy of Titan Tool Supply Company,Inc.)

(4) Endoscopes. The endoscope is much like a borescopewith a high-intensity light source, except that it has a superioroptical system which remains constantly in focus from about 4 mm(0.16 inch) to infinity. Actually, when the tip is about 4 mmfrom the surface, a magnification of about 10X is achieved. En-doscopes are available in diameters down to 1.7 mm (0.07 inch)and in lengths from 100 to 150 mm (4 to 6 inches).

(5) Mirror Adapters. Mirror adapters can be used toconvert a direct-viewing borescope into a side-viewing borescope.A mirror adapter is designed to fit over the tip of the borescopeand reflect an image from the side of the borescope. However,there is some reduction in resolution and image contrast; there-fore, not all applications are suitable for this device. A side,forward oblique, or retrospective viewing head provides betterresolution and a higher degree of image contrast than a direct-viewing borescope with a mirror adapter. A mirror adapter alsoproduces an inverse image and can produce unwanted reflectionsfrom the shaft.


R/14/97 lC43-204

(6) Scanninq. Some rigid borescopes have the ability toscan longitudinally along the axis of the shaft. A movable prismwith a control at the handle accomplishes this scanning. Typi-cally, the prism can shift the direction of view through an arcof 120 degrees. Figure 4-12 shows a typical scanning borescope.

._ --- .- - _I -.\111p11.4: :

+',

FIGURE 4-12. TYPICAL SCANNING BORESCOPE(Courtesy of Richard Wolf MedicalInstruments Corporation)

(7) Zoomina Borescooes. This instrument does not en-~.tirely fit the definition of a rigid borescope; however, it isused for inspection of bores and cavities. The zooming borescope(see Figure 4-13) can be used in aircraft maintenance for check-ing the whole interior surface of tubing and bores for surfacefinish, cracks, dirt, weld cracks, porosity, etc. It can also beused for checking the finish and chamfer on interior "0" ringgrooves and keyways. It is 3/4 inch in diameter and 4 incheslong when fully extended and contains an objective lens that mag-nifies outward in a "V" shape configuration (fisheye lens). Itcan be used on holes from 3/16 to 5 inch diameter. The whole in-


A': 43-204 8/14/97

terior diameter will be in focus at all times. On larger diame-ters, the instrument would have to be tipped slightly to focus ona specific area of sidewall. The instrument is suitable forviewing parts from 1 inch to 20 feet in length. The focus can beadjusted by holding the instrument in one hand and turning thezoom with the other hand for sharper definition of any depth offield. The area is sharp and in focus at any given focal planeand will vary from about 6 inches to 5 feet, depending on thelength of the part and distance from the instrument. For moredetail beyond 5 feet, a magnification booster is available. Thezooming borescope does not have its own light source, but relieson existing ambient light. Unless the part is very small in di-ameter, or standard room illumination is poor, no additionallight source is necessary. Should additional light be necessary,an inspection flashlight (see Table 3-8) can be held against theother end of the part.

FIGURE 4-13. ZOOM-A-BORE INSPECTION INSTRUMENT WITHMAGNIFICATION BOOSTER ATTACHED(Courtesy of Titan Tool Supply Company, Inc.)

(81 Micro-Bore Viewina System. Small area borescopeviewing systems exist for optical checking of bores and cavities(see Figure 4-14). This system does not fit the definition of arigid borescope; however, it is used for inspection of bores andcavities. The system was designed to overcome the lighting limi-


8/14/97 AC 43-204

tations of some of the micro-borescopes and will not break aseasily as the small-diameter borescope probes. This optical de-vice in the illustration comprises 17 different lenses on a ro-tary system, each with a predetermined focal length (minimum of0.020 inch to a maximum of 10 inches). It can be used for theinternal viewing of micro-bores, tubes, and cavities from 0.039to 0.315 inch diameter, with depths up to 10 inches. The illumi-nation system is adjustable and contains a 2.5 volt Halogen lightbulb. For deep cavities, additional illumination may be neces-sary, which can be provided by a small diameter inspection light.

FIGURE 4-14. MICRO-BORE VIEWING SYSTEM(Courtesy of Titan Tool SupplyCompany, Inc.)


Ac43-204 8/14/97

The micro-bore viewing system can be used in aircraft maintenancefor checking the inside of small tubes, miniature drilled, bored,and ground holes for surface finish, cracks, dirt, weld cracks,porosity, etc. It can also be used for inspecting the inside ofminiature holes in turbine blades and valve bodies.

(9) Mirror Tube Viewing Svste;,ls. These systems allowthe viewing of small holes and cavities and are meant to be inex-pensive alternatives to a rigid borescope for some applications.The system shown in Figure 4-15 allows the viewing of holes andcavities to a depth of 2 inches with 5-power magnification with-out any attachments. Included with the unit are two separatetwist-on mirror tubes, a 0.196 inch diameter, with a viewingdepth of 1 inch, and 0.236 inch diameter, which allows a viewingdepth of 1.2 inches. Illumination is provided by a miniatureHalogen light bulb projecting the illumination directly on theaxis down the hole. Powered by two AA batteries.


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FIGURE 4-15. MIRROR TUBE VIEWING SYSTEM(Courtesy of Titan Tool SupplyCompany, Inc.)

The mirror viewing system shown in Figure 4-16 is for viewingholes up to 68 inches in depth. The main probe can be 4 to 20 mmin diameter. The field of view is 30 to 70 degrees.


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FIGURE 4-16. DEEP-HOLE MIRROR VIEWING SYSTEM(Courtesy of InstrumentTechnology, Inc.)

e. Flexible Borescopes. Flexible borescopes are generallyused in applications that do not have a straight line access pathto the area to be inspected. Some typical uses of flexibleborescopes in aircraft maintenance are inspection of corrosion,


8/14/97 AC 43-204

cracks, and scratches on bore walls of castings; inspection forcorrosion and cracks of wing stringers, wing attachment fittings,spars, and other aircraft structural members; inspection of en-gine cylinder sleeves, pistons, and valves for damage; and in-spection of aircraft turbines for cracks, corrosion, damage byforeign objects, and erosion. The two types of flexibleborescopes are flexible fiberscopes and flexible videoscopes.Figure 4-17 shows some typical flaws seen through a flexible fi-berscope.

FIGURE 4-17. TYPICAL FLAWS SEEN THROUGH A FLEXIBLE FIBERSCOPE(Courtesy of Olympus Corporation)


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(1) Flexible Fiberscooes. A typical flexible fiberscopeconsists of a fiber-optic light-guide bundle, a fiber-optic im-age-guide bundle, an objective lens, interchangeable viewingheads, and remote controls for articulation of the distal tip.Flexible fiberscopes are available in diameters from 0.055 to 0.5inch and in lengths of over 300 feet. The light-guide bundle isused to carry illumination from a remote source to the distaltip. Since each fiber in the light-guide bundle transmits onlyillumination and not an image, the fibers do not have to be pre-cisely aligned and are generally larger than those in the image-guide bundle. The image-guide bundle is used to carry the imageformed by the objective lens back to the eyepiece, and the fibersin the image guide are precisely aligned so that they are in anidentical relative position to each other at their terminationsfor proper image resolution. The diameter of the fibers in theimage guide is a factor in obtaining good image resolution. Alarge number of small-diameter fibers in the image-guide willprovide a bright image with high resolution (see Figure 4-18).High resolution allows the use of an objective lens with a widerfield of view and also allows magnification of the image at theeyepiece for better viewing of objects at the periphery of theimage (see Figure 4-19). Interchangeable distal tips providevarious directions and fields of view on a single fiberscope;however, because the tip can be articulated for scanning pur-poses, distal tips with either a forward or side viewing direc-tion are usually sufficient. Fields of view are typically 40 to60 degrees, although they can range from 10 to 120 degrees. Mostfiberscopes provide adjustable focusing of the objective lens.

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FIGURE 4-18. COMPARISON VIEWS WITH DIFFERENT QUANTITIES OFFIBERS IN THE FIBERSCOPE IMAGE BUNDLE(Courtesy of Olympus Corporation)


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Chap 4

FIGURE 4-19. FLEXIBLE VIDEOSCOPE IMAGES(Courtesy of Welch Allyn, Inc.)

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(2) Flexible Videoscooes With CCD Probes. Flexible vid-eoscopes have CCD imaging sensors at the distal tip to electroni-cally transmit color or black and white images to a video moni-tor. The fiber-optic image bundle inside the insertion tube isreplaced by a wire assembly to carry video information. Video-scopes with CCD imaging sensors produce images with spatial reso-lutions on the order of those described in Figure 4-20.

o14eaoopoD 0 10 40 m m loo om*Y)(9goOBJECT DISTANCE MY OIJCCT DISTANCE MU OSJECT DISTANCE YU

FIGURE 4-20. TYPICAL CCD VIDEOSCOPE RESOLUTION(Courtesy of Welch Allyn, Inc.)

The resolution of videoscopes, like rigid borescopes and flexiblefiberscopes, depends on the object-to-lens distance and the fieldof view, since these two factors affect the amount of magnifica-tion. Generally, videoscopes produce higher resolution than fi-berscopes, although fiberscopes with smaller diameter fibers canbe competitive with the resolution of videoscopes. A primary ad-vantage of videoscopes is their longer working length. With agiven amount of illumination at the distal tip, videoscopes canreturn an image over a greater length than fiberscopes. Otherfeatures of videoscopes include (1) the display can help reduceeye fatigue (but does not allow the capability of direct viewingthrough an eyepiece); (2) there is no honeycomb pattern or ir-regular picture distortion as with some fiberscopes (see Figure4-21); (3) the electrical image signal allows digital image en-hancement and the potential for integration with automatic in-spection systems; and (4) the display allows the generation ofretitles on the viewing screen for point-to-point measurements.


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FIGURE 4-21.

Page 146

COMPARISON BETWEEN VIDEOSCOPE AND FIBERSCOPE IMAGES(Courtesy of Welsh Allyn, Inc.)

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f. BorescoDes With SDecial Featura . Borescopes, fiber-scopes, video systems, and related equipment are being used formore purposes, more complex inspections, and even some limitedrepair applications. Some of the borescope products briefly de-scribed are measuring borescopes and fiberscopes, working chan-nels, flying probe, VideoHook Probe, power blending borescope,and ShadowProbeTM.

(1) Ueasuina Rorescooes and Fiberscooes. Measuringborescopes and fiberscopes contain a moveable cursor that allowsmeasurements during viewing (see Figure 4-22). When the objectunder measurement is in focus, the movable cursor provides a ref-erence for dimensional measurements in the optical plane of theobject. This capability eliminates the need to know the object-to-lens distance when determining magnification factors. Measur-ing borescopes and fiberscopes can be used in aircraft mainte-nance for measuring cracks in aircraft turbine liners, blade dam-age, etc.

FIGURE 4-22. VIEW THROUGH A MEASURING FIBERSCOPE(Courtesy of Olympus Corporation)

(2) Workina . Working channels are used inborescopes and fiberscopes to pass working devices to the distaltip. Figure 4-23 shows a retrieval tool in a working channelpicking up a screw inside a machine. Table 4-3 shows some typi-cal devices for use in working channels. Working channels arepresently used to pass measuring instruments, retrieval devices,and hooks for aiding the insertion of thin, flexible fiberscopes.Working channels are used in flexible fiberscopes with diameters


AC: 43-204 8/14/97

as small as 0.106 inch. Working channels are also under consid-eration for the application and removal of dye penetrants and forthe passage of wires and sensors in eddy current measurements.Retrieval tools are typically used in aircraft maintenance forremoving objects from aircraft turbines and appliances that mayhave been dropped during maintenance and repair work.

FIGURE 4-23. RETRIEVAL DEVICE IN BORESCOPE WORKING CHANNEL(Courtesy of Olympus Corporation)


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TABLE 4-3. TYPICAL WORKING CHANNEL DEVICES(Sheet 1 of 2)(Courtesy of Olympus Corporation)

TYPEA. SAMPLING FORCEPS1. Standard(Fenestrated

2. Ellipsoid(Fenestrated)

3. Alligator

4. Crescent

5. Hexagonal

COMMENT

Round jaws for normal grasping.

Longer jaws in order to grasp morethan the standard type.

Designed for scooping with sideopening jaws.

For lassoing foreign objects.


6. Oval

0


, IB. GRASPING FORCEPS1. Tripod

I/1

Good for gripping larger solid ob-jects

2. Hooked Jaws

LiGood for clenching into softer ob-jects.

I I3. "W" Shaped

Y

Collects flat foreign objects,e.g., coins.

4. Alligator Jaws 0

d

Designed to prevent slipping, gripwell.

5. Rat Tooth r Jaws hinge together to providegood grip.

6. Pelican Type

T

Useful for awkward foreign ob-jects.

7. Basket Type Basket tightens up on an objectfor removal, e.g., ball bearings.


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TABLE 4-3. TYPICAL WORKING CHANNEL DEVICES(Sheet 2 of 2)(Courtesy of Olympus Corporation)

8. Rubber Tipped JLWSF?

Good for grasping smooth surfaces.

5C. MAGNETIC EXTRACTORSCylindrical Shape PI '

'i

Good for retrieving ferromagneticforeign objects.

(3) Flvina Probe. In the so called Flying Probe, aflexible video borescope uses an air jet microthruster to helpposition a flexible video probe in an area to be viewed (see Fig-ure 4-24). The air jet force can be used to pull the distal tipof the flexible video borescope through cavities to locationspreviously unreachable by traditional borescope techniques. Theair jet microthruster system is particularly suitable for air-craft engine and structural inspections that would otherwise re-quire the use of guide tubes.

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FIGURE 4-24. FLYING PROBE FLEXIBLE BORESCOPE(Courtesy of Welch Allyn, Inc.)

(4) YideoHook Probe . This probe consists of a specialhook attachment at the distal tip of a flexible video probe (seeFigure 4-25). The special hook attachment can be hooked onto thefirst stage turbine blade of a Pratt & Whitney JT8D series enginefor more complete viewing of the second-stage, high-pressure tur-bine vanes. After hook attachment, the engine rotor is slowlyrotated manually to allow viewing of the full second-stage vanes.The hook attachment can be slipped onto the distal tip of the


A::43-204 8/14/97

VideoHook Probe, with no special tools or working channel re-quired, and can be easily removed when the inspection is com-pleted. The hook is made of special soft aluminum that will re-duce damage should it be left behind in the engine.

FIGURE 4-25. VIDEOHOOK PROBE ATTACHMENT FOR A FLEXIBLEBORESCOPE (Courtesy of Welch Allyn, Inc.)

(5) Power Blendina Borescooe Kit. A combined borescopeand blending system can detect and repair (i.e., blend) foreignobject damage on the 7th-stage compressor blades of JT8D-200 se-ries engines (see Figure 4-26). The power blending borescope al-lows engine repair with the engine installed on the aircraft andwithout engine disassembly. The power blending procedure is ac-


8/14/97 AC 43-204complished with a specially designed borescope and working chan-nel. A rotary file or stone is connected to a drive cable thatpasses through the working channel and a drive motor connected tothis cable rotates the cutter/stone,variable-rate foot pedal.

with speed controlled by aThe technician operates the tool to

blend damaged blades while viewing the work process on a videomonitor. A video micrometer is also incorporated into the systemto allow measurements to be taken.

FIGURE 4-26. POWER BLENDING BORESCOPE KIT(Courtesy of Machida, Inc.)

(6) ShadowProbeTM. The ShadowProbeTM measuring fiber-scope system measures cracks, defects, and small objects whileconducting remote inspections (see Figure 4-27). The Shadow-ProbeTM system is designed to make measurements without compari-son to reference objects by casting a shadow pattern across thesystem image, which is used by a system on-board computer to de-


AC 43-204 8/14/97

termine magnification, distance, object size and dimensions. OP-erators manipulate a cursor on a video screen to locate theshadow and objects to be measured. The video screen is elec-tronically corrected for lens distortion and has built-in auto-matic calibration for magnification from near or far away, over afull 85-degree viewing field. No reference point is required andthere is keyboard access to three different measurement modes toallow measurement of linear distance, depth, or objects at skewedangles.

FIGURE 4-27. SHADOWPROBETM MEASURING SYSTEM(Courtesy of Welch Allyn, Inc.)

g. Borescooe Selection Ouestrox. By answering the follow-ing questions and reviewing the information in this document andborescope manufacturers' literature, a prospective borescope usercan determine which borescope offers advantages over another for


8/14/97 AC 43-204

a specific inspection. The answers to these questions can alsobe used as a guide for selecting or purchasing the most effectiveborescope for a particular application.

(1) Access Ooenins Inside Diameter (i.d.1. How wide isthe borescope entry point and what is the smallest i.d. that theborescope should pass through?

(2) Travel Path Geometry.straight or curved?

Is the travel path geometryIf a guide tube is required, what is the

most severe bend the guide tube should negotiate and what is thei.d. at this point?

(3) Guide Tube. Is a guide tube needed to facilitateborescope insertion? Is it offered with the borescope? Will ithave to be custom manufactured or formed on site?

(4) Borescope Length. What is the minimum length neededto travel to reach the inspection site? Is additional lengthneeded for protection of the eyepiece or safety of the inspectorusing the borescope? Is a drawing available to study and lay outthe access path requirements? The length of the borescope inser-tion probe should be well thought out, since it is related tocosts and a longer insertion tube can be difficult to control inan inspection with a shallow travel path. In many circumstances,two separate borescopes for different inspections will be moreeconomical than using one scope for multiple purposes. The prob-ability of damage and cost of repair increases with increasedborescope working length.

(5) Tar-set Insoection Area Location. Where is the tar-get inspection area in relation to the distal tip when theborescope reaches the target? If a flexible borescope is beingconsidered, is there room in the work piece channel for articu-lating the bending section to face the target inspection area di-rectly? How far from the target inspection area will theborescope tip be during the inspection? Will variable magnifica-tion and direction of view tip adapters be required now or later?

(6) Resolution. What is the smallest dimension neededto be seen? Can the defect be large or are microscopic defectsalso harmful? What will happen if a microscopic defect ismissed?

(7) Frequency of Borescope Use. How often will theborescope be used? How long will the borescope be used for eachinspection? How many inspections will be made for each use? Howmany people will use the borescope?


AC43-204 8/14/97

(8) Documentation. Will photo or video documentation ofthe inspection/defect be needed?

(9) Verification of Borescope Specifications. Can theborescopes specifications be verified independent of the sup-plier?

(10) Borescope Operation. Is an operating manual pro-vided with the borescope that is adequate for the user's needs?Is training available to improve inspection results and reducewear and tear on borescopes?

405. LIST OF EGUIPMENT USED IN VISUAL INSPECTION. Appendix Gprovides a partial listing of equipment useful in accomplishingvisual inspections.

406.-499.

Pages 156 through 166

RESERVED.

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CHAPTER 5. DEFINITIONS

500.

AC -AD -CRF -CIE -MF -FAA -FAR -HID -IES -K -MSDS -NFPA -ND1 -NDT -SB -SSID -UL -

DEFINITIONS.

Advisory CircularAirworthiness DirectiveCode of Federal RegulationsInternational Commission on IlluminationElectromotive ForceFederal Aviation AdministrationFederal Aviation RegulationHigh-Intensity discharge (type of illumination)Illumination Engineering SocietyKelvinMaterial Safety Data SheetsNational Fire Protection AssociationNondestructive InspectionNondestructive TestingService BulletinSupplementary Structural Inspection DocumentUnderwriters' Laboratories, Inc.

ACTIVE: Referring to the negative direction of electrode poten-tial (opposite of noble).

ANEROBIC: An absence of oxygen in the uncombined state.

ANGSTROM (A):of wavelength.

Unit of length usually rgserved for the expressionOne angstrom equals 10 centimeter (cm). Under

the standard system of units, the angstrom will be replaced bythe nanometer (nm) (1.0 A = 0.10 nm). The angstrom is the stan-dard unit for measuring wavelength of light.

ANODE: An electrode at which oxidation of the anode surface orsome component of the solution is occurring (opposite of cath-ode).

BRIGHTNESS: The strength of sensation which results from viewingsurfaces or spaces from which light comes to the eye. This sen-sation is determined in part by luminance (which can be measured)and in part by conditions of observation, such as the state ofadaptation of the eye.

BULB: A source of electrically powered light. This term is usedto distinguish between an assembled unit consisting of a lightsource in a housing called a "lamp" and the internal source. SeeLAMP.

CANDELA (cd) : The metric unit of luminous intensity. One can-dela is one lumen per steradian (formally candle).


T\c 4 3 - 2 0 4 a/14/97

CATHODE: The electrode of an electrolytic cell at which reduc-tion occurs (opposite of anode).

CELL: An electrochemical system consisting of a cathode and an-ode immersed in an electrolyte. The anode and cathode may beseparate metals or dissimilar areas on the same metal.

CHARGE-COUPLED DEVICE (CCD) : A microchip imaging sensor contain-ing thousands of light-sensitive elements (pixels) arranged in apattern of rows and columns. The CCD converts light from an im-age to electrons which, after processing, can be displayed as apicture on a video monitor.

CIE: International Commission on Illumination

CLEAN: Free of contaminants.

CONCENTRATION CELL: A cell in which potential differences at theanode and cathode are the result of differences in chemistry(concentration of reactants or products) of the environment adja-cent to the electrode.

CONTAMINANTS: Any material or material residue which interfereswith the visual inspection process.

CORROSION: An electrochemical deterioration of a material, usu-ally a metal, because of a reaction with its environment. (SeeAC 43-414).

CORROSION FATIGUE: A yielding of a metal resulting from the com-bined action of corrosion and fatigue (cyclic stressing).

CKAZING: Network of minute cracks appearing in the surface of amaterial.

CREVICE CORROSION: A localized corrosive attack resulting fromthe formation of a concentration cell in a crevice between twometal surfaces of a metal and nonmetal surface.

DEFECT: A discontinuity or group of discontinuities which do notmeet specified acceptance criteria. One can have a defect withinacceptable limits.

DEPOSIT: A for-eign substaIlce, which comes from the environment,adhering to a surface of a material.

DIRECT GLARE: Glare resulting from high luminances or insuffi-ciently shielded light sources in the field of view. It is usu-ally associated with bright areas, such as luminaires, ceilingsand windows whic1l ar-e outside the visual task or region beingviewed.

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DISBOND: Areas where adhesive bonding no longer meets designedstrength requirements.

DISCONTINUITY: An interruption in the normal physical structureor configuration of a part such as a crack, lap joint disbond,seam, inclusion, area of corrosion, or porosity. See DEFECT.

DUST-PROOF LUMINAIRE: A luminaire so constructed or protectedthat dust will not interfere with its successful operation.

DUST-TIGHT LUMINAIRE: A luminaire so constructed that dust willnot enter the enclosing case.

ELECTRODE: An electrical conductor in contact with an electro-lyte which serves as an electron acceptor or donor (see anode andcathode as specific examples).

ELECTROLYTE: A chemical substance or mixture, usually liquid,containing ions which migrate in an electric field.

ELECTROMOTIVE FORCE SERIES: A list of elements according totheir standard electrode potentials with the value for hydrogenarbitrarily taken as 0.0 volt (also called Emf series).

EMBRITTLEMENT: A loss of load carrying capacity of a metal oralloy.

ENCLOSED AND GASKETED: See vapor-tight.

ENVIRONMENT: A description of the surroundings or conditions(physical, chemical, mechanical) in which a material exists.

EVALUATION: The review of discontinuities to determine if theymeet specified acceptance criteria.

EXFOLIATION: A thick, layered growth of loose corrosion productsoften separating from the metal surface.

EXPLOSION-PROOF LUMINAIRE: A luminaire which is completely en-closed and capable of withstanding an explosion of a specific gasor vapor that may occur within it and preventing the ignition ofa specific gas or vapor surrounding the enclosure by sparks,flashes or explosion of the gas or vapor within. It must operateat such an external temperature that a surrounding flammable at-mosphere will not be ignited thereby.

FAYING SURFACE: Interface between two adhesive surfaces.

FIELD OF VIEW: The angle in degrees that the entering light sub-tends at the exit pupil of the optical system. Also known asANGLE OF FIELD.


AC 43-204 8/14/97

FILIFORM CORROSION: A form of attack that occurs under films onmetals and which appears as randomly distributed hairlines (alsocalled Underfilm Corrosion).

FLAW: An imperfection in an item or material. Small flaws canbe harmless. See DISCONTINUITY.

FOOTCANDLE: The unit of illuminance when the foot is taken asthe unit of length. It is the illuminance on a surface onesquare foot in area on which there is a uniformly distributedflux of one lumen or the illuminance produced on a surface allpoints of which are at a distance of one foot from a direction-ally uniform point source of one candela.

FRETTING CORROSION: A form of deterioration caused by repetitivefriction between two sliding surfaces and accelerated by a commoncorrosive action.

GALVANIC CELL: A corrosion cell consisting of two dissimilarmetals in contact or in a narrower context consisting of adjacentanodic and cathodic sites. The former definition is on a macro-scale, the later on a micro-scale.

GALVANIC CORROSION: A type of corrosion associated with the cur-rent resulting from the coupling of dissimilar electrodes in anelectrolyte.

GALVANIC SERIES: A listing of metals arranged according to theirrelative corrosion potentials in a specific environment (such assea water).

GENERAL CORROSION: A type of corrosion attack uniformly distrib-uted over a metal surface (sometimes called uniform etch corro-sion) .

GRAIN BOUNDARY: A narrow zone in a metal corresponding to thetransition from one crystallographic orientation to another, thusseparating one grain from another. The atoms in each grain arearranged in an orderly pattern.

HEAT-AFFECTED ZONE: An area adjacent to a weld where heat hascaused microstructural changes which affect the corrosion behav-ior of the metal.

HID: High Intensity Discharge (Type of illumination)

HYDROGEN EMBRITTLEMENT: A reduction of the load carrying capa-bility by entrance of hydrogen into the metal (e.g., during pick-ling or cathodic polarization).

HYDROGEN-STRESS CORROSION: A premature failure of a metal re-sulting from the combined action of tensile stresses and thepenetration of hydrogen into the metal.

Page 170Chap 5

Par 500

a/14/97 AC 43-204

IES: Illumination Engineering Society

ILLUMINANCE: The density of the luminous flux incident on a sur-face; it is the quotient of the luminous flux divided by the areaof the surface when the latter is uniformly illuminated.units are footcandles and lumens.

Typical

ILLUMINATE: To provide, cover, or fill with light.

LUMINANCE: The luminous flux from a point divided by the areaupon which it falls. See IES Handbook. (Formerly PHOTOMETRICBRIGHTNESS.)

LUMINANCE RATIO: The ratio of the luminances of any two areas inthe visual field.

MARINE ENVIRONMENT: An environment immediately adjacent to thesea coast affected by prevailing winds, fog, and other factors.

METAL: In the context of this advisory circular, a metal, metal-lic alloy, or material or combinations of those which exhibitmetal-like properties (are electrical conductors) and are subjectto corrosive attack.

NANOME ER:-a A unit of length equal to one billionth of a meter,or 10 meter. The nanometer has replaced the angstrom unit as ameasurement of short wavelength, electromagnetic radiation.

NEWTON (N): The unit of force equal to 0.2232 lb.

NFPA: National Fire Protection Association

NOBLE: Refers to the positive direction of electrode potential,thus resembling the noble metals (such as gold).

NONDESTRUCTIVE INSPECTION: Inspection to detect internal or con-cealed defects in materials using techniques that do not damageor destroy the items being inspected.

OBJECTIVE LENS: The optical lens nearest the object being viewedthat receives the light from the object.

PASSIVE: A condition in which the behavior of a metal is morenoble (less active) than its position in the Electromotive ForceSeries would predict. A surface film protects the underlyingmetal from corrosion (opposite of active).

PASSIVITY: A phenomenon by which an active metal becomes pas-sive.


AC43-204 8/14/97

PITTING: A very localized type of corrosion attack resulting indeep penetration at only a few sites (opposite of general corro-sion) .

PHOTOMETRY: The measurement of quantities associated with light.

REFLECTANCE OF A SURFACE OR MEDIUM: The ratio of the reflectedflux to the incident flux.

REFLECTED GLARE: Glare resulting from reflections of high lumi-nances from polished or glossy surfaces in the field of view. 1tis usually associated with reflections from within a visual taskor areas in close proximity to the region being viewed (see veil-ing reflections).

ROOM UTILIZATION FACTOR: The quotient of the luminous flux(lumens) received on the work-plane divided by that emitted bythe luminaire.

RELATIVE HUMIDITY: A ratio (percentage) of the amount of mois-ture in the air compared to what it could hold if saturated at agiven temperature.

RESIDUAL STRESS: A stress present in a metal that is free of ex-ternal forces or temperature gradients, usually the result offabrication processes, and can be tensile or compressive in na-ture.

RUSTING: A type of corrosion attack limited to ferrous materialswhich results in reddish-brown corrosion products.

SACRIFICIAL PROTECTION: A reduction or prevention of corrosionof metal by galvanically coupling it to a more anodic metal.

SCALING: A formation at high temperature of thick corrosionproduct layers on a metal surface or the deposition of water in-soluble constituents on a metal surface.

SEEDS: Small bubbles in glass introduced during the manufactur-ing process.

SMOKE, SMOKING: A haze of solid detritus (blackened aluminumcompounds) caused by abrasion of a loose rivet and its surround-ings.

STERADIAN (UNIT SOLID ANGLE): A solid angle subtending an areaon the surface of a sphere equal to the square of the sphere ra-dius.

Page 172Chap 5

Par 500

8/14/97

STRESS-CORROSION CRACKING: A premature failure of a metal as theresult of the combined action of tensile stresses and a corrosiveenvironment.plied.

The surface tensile stresses may be residual or ap-

TARNISH: A surface discoloration of a metal caused by the forma-tion of a thin film of corrosion product.

THRESHOLD STRESS: A limiting stress at which stress-corrosion orhydrogen-stress cracking will develop in a metal in a given expo-sure period.

VAPOR-TIGHT LUMINAIRE: A luminaire designed and approved for in-stallation in damp or wet locations. It is also classified as“enclosed and gasketed."

VEILING REFLECTIONS: Regular reflections superimposed upon dif-fuse reflections from an object that partially or totally obscurethe details to the seen by reducing the contrast (sometimescalled reflected glare).

VISUAL TASK: The process of observing an object either with theaided or unaided eye and making an informed assessment of itscondition.

WATTS (W): Time rate of transferring energy. Power equal to onejoule per second. The following table is a conversion of lightvalues to units of power.

Light Source* cd/in< kcd/m<Clear sky 5.16 a

Candle flame (sperm) 6.45 10

160-W inside frosted bulb I 77.4 I 120 I160-W “white bulb" I 19.35 I 30 I

I Fluorescent lamp, cool white, T-12 bulb, 5.3 a.2medium loading I

I High-intensity, mercury-arc type H33, 2.5 I 968 I 1,500 II atm I I IClear glass neon tube, 15 mm, 60 mA 1.03 1.6 I

RESERVED.

Chap 5Par 500 Pages 173 through 182

8/14/97

APPENDIX A. BEACHCRAFT, ATA CODE 57-10SAMPLE INSPECTION PROCEDURE

AC 43-204Appendix A

Wing Front Spar-Inspection of Upper and Lower Spar Caps.

Retyped with permission of Beachcraft A Raytheon Company.

Page 1

i\c 43-204Appendix A

8/14/Y'/

Service Instructions No. 0514.035, Rev. II

SAMPLE INSPECTION PROCEDURE

AII Models Except 17, 18, 19, 23. 24. 76 and 77 NO. XXXX-XXX. Rev. XATA Code 57.10

Rccwru~g lnspectlon

Kit No. 35-4008-l sKi t No. 58-4002- l s

Ki t No. 100-4002- l sKit No. 100s4002-3 SIGt No . 100-4002-4 S

SURJECT:

SYNOPSIS OFCHANGE:

EFFECTIWI-Y:

U’lNG FHONT SPAR. INSPECTION OF UPPER AND I.Ob-ER SPARC A P S

Added Super King hr 200 sencs to mspecoon Added Lnforrna~on announcingspar replacement kits.

BEECHCWFT Deboncur,Booanza 35.33 senes;Bonanza 35 senes;Bonanza 36 series;AlI >fodel 45 (T34A). B45 arld D45 tT34Bi airplanes:?v.ln Bonanza 50 series.Baron 95.55 senes.Baron 56TC series..Baron 58 senes.Duke 60 series.Queen Air 65 series.Queen Au 70 senes.Queen AH 65-80 sews.Queen ti 65.88 senes.King hr 65-90 senes.Travel Air 95 series;99 Airhner senes.King Au 100 series.Super King hr 200 series.that are 5 years old or older.

SOTE

Page 2

8/14/97 AC 43.-204Appendix A

REASON:

COMPLIANCE:

APPROVAL:

MANPOWER:

MATERLAL:

MODEL

Service Instructions No. 0514-035, Rev. II

and/or stored for extended periods (5 years or longer) in areas wheregeographical location and atmospheric conditions are highly conductive toc0ms10n.

To inspect the upper and lower spar caps for possible con-osion.

Withm the next 100 hours tune LII seMce and at each subsequent annualmspection thereafter.

FAA Approved.

The followmg mformatlon is for plw purposes only:

Estimated man-hours for inspection: 1 hourSuggested number of men: 1 man.

If replacement of the wing main spar becomes necessary, spar installation kitsare available for some models. For replacement spars on models not listedbelow and required installation parts not contained in the kits listed below.refer to the applicable BEECHCRAFT Parts Catalog. Kits and/or parts. ifrequred. may be ordered through BEECHCRXFT Aem or Aviation Centersand Intematnonal Distibutors and Dealers. The value of the kits and/or parts,requved for the incorporauon of these Service Instructions on one auplane isto be advised. Prices, when issued. MU be subject to change without notice.Beech An-craft Corporation expressly reserves the nght to supersede. canceland/or declare obsolete any kits or publications that may be referenced in theseService Instructions without pnor nohce.

NOTICE

Al l BEECHCRAFT kits, un le s s o the rwise des igna ted . a re approved fo rmstallataon on BEECHCRAFT airplanes m ongrnal or BEECHCW modifiedconfigurations only. BEECHCRAFT luts may not be compatible with airplanesm o d i f i e d b y S T C installation o r modtficatlon o t h e r t h a n BEECHCRrU7approved kits.

PART NUMBER QUAKTI’IYDESCRIPTION

Kit. Spar Inst’l. (containsp a r t s a n d InformatIon t oInstall n e w fwd. wngspars. S p a r s a r e n o tI n c l u d e d O r d e r P.‘N OOO-110011.1iLH) or P/Y OOO-11001102tRH~ s p a rassemblies I N o t e : All 3 5serves alrplanes prior to D-4666 m u s t r e p l a c e b o t ht h e L H a n d R H s p a r ss~mult~nrousl~ wnrnInstalling fwd ‘.V I I, q,pZirs 1

2 per airplane

Page 3

AC 43-204Appendix A

8/14/3’1

Service Instructions No. 051-i-035, Rev. II

MODEL

.*I 95..55 :irouqh E5S. 56.95 througn E95. 56TC. 60a n d A 6 0

All 65. A65: 70: 65-80. 65.AgO. 65.BdO thru LD-477;65-66: 65.90. 65.A90. B90.C90 throuqn U - 6 2 4 . E90t h r o u g h LW-67: 9 9 , 99A.A99A 899 through U-153that have not replaced theO.B. wtng maln spar perService Instructtons N o .0986 o r subsequen t ; 100and Al00 through B-193

Same as 100-4002-l S

Same as 100-4002-l S

PART LUMBER DESCRIPTION

Kit. Spar Inst’l . Iccn!alnsp a r t s a n d Informa:lon :cinstall n e w fwd wngspars. S p a r s are n o tIncluded. Order PIN OOO-110011~XLH) or P.W Ooo-llOOll-4(RH) for 95 and55 series aIrplanes: orderP M 000-110011-5(H) o rPM OOO-110011.6(RHi for58 series airplanes: orderP/N OOO-llOOll-7(LHj o rPM 000.llOOll-ENRH) for56TC and 6 0 seriesaqlenes.)

100-4002-l S Kit. L H S p a r Inst.1icontalns p a r t s a n dlnformatton to Install newfwd. wing spars. Sparsare not Included. orderP M OOO-110012-1tLHi o rP/N OOO-110012.2rRH1spar assembllesr

10@400”-3 s I&t. LH Spar Inst’l. (samea s k i t P/N 100~4002-1 Se x c e p t Pil\l 000~110012-1spar assy. IS Included.)

100-4002.4 S Kit. LH Spar Inst’l. (samea s kit P I N 100-4002~1 Sexcept Pm 000-110012-2spar assy. 1s Included.1

2 per amplane

1 per auplane

1 per auplane

WARRANTY: None.

SPECUL TOOLS: Sane.

WEIGHT ANDBALANCE: None.

REFERESCES: The applicable Parts Catalog for all models on ~.hxh spar lnstallanon lilts do notmclude the spars or ou which spar mstallahoo lut.s are not avdable.

PUBLICATIONSAFFECTED: It IS recommended that a note be made in the apphcnble section of all s hip manual

copies to “ S e e Serwce Irlsm~ctlous S o . 0513-035. R e v . I1 f o r s p a r lnspectlonprocedures.”

I?age 4

8/14/97 AC 43-204A p p e n d i x A

Service Instructions No. 0514-035, Rev. II

ACCOMPLISHMENT’INSTRUCTIONS: The inspection of the upper and lower spar caps may be accomplished as described in

the followmg pmcedure.

1. Wash all exposed area of the upper and lower spar caps usmg normal cleamng procedures.

2. Visually mspect al.l e.qosed area of the upper and lower spar caps for pamt blisters, raued areasand/or unevenness and cracks in the metal. Pa.mt blisters could be caused by corrosion. therefore. lfbhst.ersm detected during the visual inspection the area of the blister should be exarmned closely for unevennessan&or raised areas and cracks in the metal. The eqosed area of the spar caps are extruded flat therefore,areas of unevenness and/or raised areas on the spar caps could indicate corrosion and should be consideredsuspect areas. (See illustration.)

NOTE

heas of unevenness and/or raued areas on the spare caps may bedetected by sliding the fmgers over the surface, by moving astraightedge over the surface or by sighting down the length of thespar cap.

3. If during visual inspecaon. any build up of a whitish salt-like non-metallic substance 1sdetected, the area should be exammed carefully. as this is indicaave of corrosion. However. W&Y orpamt that may be trapped between the edge of the S!-LZI and the exposed secnon of the spar cap shouldnot be interpreted as corrosion.

4. If unusual conditions are noted which cannot be resolved locally. advise CommercmlProduct Support. Beech Aircraft Corporation, Wicmta, Kansas 67201.

5. For models on which spar installation kits are available. mstlvctions for installation of thereplacement spars are continued in the applicable kits.

P a g e 5

.fl(: 43-204Appendix A

B/14/97

Service Instructions No. 0514-035. Rev. II

THIS lLLUSTF4ATlON REPRESENTS A

r BOX SECTION SKINTYPICAL SECTION OF THE SPAR CAPAREAS TO BE INSPECfED FORINDICATORS OF KXSSl8LE CORROSION.THE INDICATORS ARE ALL SHOWN IN ONEAREA AN0 ARE EXAGGERATED FOR CURrrY

CRACKS ANY ONE OR ANY COMBINATION OF THEINDICATORS ARE CAUSE FOR FURTHER

VARY

Typtul Sedon of m0 spar Cap IO bo ln8fmct.d

R E C O R DCOMPLIANCE: Upon completion o f t h e uuoal a n d a l l s u b s e q u e n t lnspecnons. m a k e a n

appropriate mauntenance record enm. Wnen k i t s a r e -talled, it ISrecommended tha t the pans hst conmned in the k i t be f i led for fu turereference

E?age 6

a/14/97

APPENDIX B. BEACHCRAFT, ATA CODE 55-30SAMPLE INSPECTION PROCEDURE

AC 43-204Appendix B

Empennage-Vertical Stabilizer - Part I, Inspection of theVertical Stabilizer Main Spar For Fatigue Cracks and/or Nicks:Part II, Repair of Fatigue Cracks and/or Nicks in the Vertical

Stabilizer Main Spar and Angle-Doubler.

Retyped with permission of Beachcraft A Raytheon Company

Page 1

AC 43-204Appendix B

8/14/9'1

I

Service Instructions No. 0530-134. Rev. 1


CLASS I

SUBJECT:

SYNOPSIS OFCHANGE:

EFFECTIVIm:

REASON:

COMPLIA3’CE: PART I a. Inspecnon at 2000 hours of time in service.

EMPENNAGE - CTERTICAL STABILIZER - PART I, INSPECTION OFTHE VERTICAL STABILIZER MAIN SPAR FOR FATIGUE CRACKSAND/OR NICKS; PART II, REPAIR OF FATIGUE CRACKS AND/ORMCKS IN THE VERTICAL STABILIZER MAIN SPAR AND ANGLE-DOUBLER

Changed Part I to reqture removal of the vertical stabilizer for mspechon andchanged mapecnon procedures.

BEECHCRAFT 99,99A. A99A and B99 A&net-s.. serials G- 1 thou C- 151 ultb2000 hours or more of hme ~ri service. unless the intent of these .Ser,lceInsuucuons has already been accomplished.

To provide procedures for mspecnng the vemcal stabilizer marn spar anda n g l e - d o u b l e r f o r p o s s i b l e fatque cracks and/or tucks a n d r e p a i r o rreplacement of vemcal stabihzer lfcracks or nicks are found.

PART I b. Inspecaon at intervals not to exceed 500 senqce hours after theLLU~ mspecraon m Part I a. unnl the new P,FJ 115-640000-605 stabilizer 1smstalled

PART II. Repair or replace the vertical stabhzer as indicated in these SenqceIIl!Stl-UCUOClS.

NOTE

The vemcaI stabthzer can be replaced or the doubler repair can bemade as a suengthemng measure at any ume d the vemcal stabilizeris removed from the au-plane for any reason. If the doubler repav ismade following detecuon of a cracked spar or angie-doubler. the 500hour mspecnon intervals described herem should be conunued. If thedoubler 1s mstahed as a strengthening measure with no evidence ofcmcks in the spar. of if a new vcmcal stabilizer IS installed. inspectionof the area may revert to normal rouune inspecuon intervals.

?age 2

8/14/97

Service Instructions No. 0530-134, Rev. I

DESCRIPTION: On the ~rxlnal inspection, the vertrcal stabilizer is to be removed from thefuse lage and the mam spa r and ang le -doub le r a re to be dye penetrantmspected for possible fatague cracks. If cracks are found. the stabilizer 1s tobe rep-d or replaced as described her->m. If mcks are noted m the flanges.they are to be sanded smooth as described her-em. The doubler reinforcementdescribed in Part II is to be made. or as an opuon. the vemcal jmbilxer is tobe replaced regardless of the mspectlon results.

If the doubler repair is made following detecoon of a cracked spar or angle-doubler, the vertical stabilizer main spar flanges are to be visually inspectedmth a 3 to 5 power magnifying glass at each 500 hour Interval there&r undthe vertical stabtizer has been replaced.

APPROVAL: FAA Approval DOA CE-2.

MANPOWER: The followmg informanon rs for plw purposes only

Estrmated manhours for first inspection: 8 hours.Suggested number of men for first inspecuon. 2 men.Estimated man-hours for inspection followmg a doubler rcpalr of a crackedspar 2 hours.Suggested number of men for mspechon following a doubler rrparr ofa crackeds p a r 1 m a n .Estunated man-hours for doubler installanon: 16 hoursSuggested number of men for doubler installanon. :! men.Estunated man-hours for stabilizer replacement: 2.1 hoursSuggested number of men for stabilizer replacement. :! men

MATERIAL: The followng parts. Lfrequrred. may be obtained through your BEECIICRGTParts and SeMce Outlet

.‘;EW P,% OLD P./N DESCRIPTION

Vttrucai Stabilizer.%xemblyCherrylock rivetCherrylock rivet

‘Eshmated suggested selling price. (Subject to change wltbout nouce.)

WAHRAN-I-Y: NOUt?

SPECIAL TOOLS: None

WEIGHT ANDRALANC E: WEIGHT A R M XIOMENT

rI,BS I 1 INS1 1 LBS. INS,

Paqe 3

AC43-204Appendix B

Service Ins t ruc t ions No. 0530-134, Rev. I

PUBLICATIONSAFFECTED: It IS recommended that a now to “See Servce lnsm~cnor~ So 0530-13-i. Rev.

I” be made m all 99 through B99 Parts Catalog copses. PS c?Y.ScjOOl-ID orsubsequent. Figure 134.

ACCOMPLISHMENTINSTRUCTIONS: These Service Instrucnons may be accomphshed as follows

PART I a. FIRST INSPECTION

1. R e m o v e t h e r u d d e r a n d t h e vertical s t a b i l i z e r a s tnstructed III Chapten ‘27-20 a n d 55-30respecnvely of the Mantenance Xlaoual.

2. Drill out the rivets on both sides of the lower vemcal stabilizer sufBciently to Lift the S~US andinspect the main spar and the angle-doubler.

3. Csing dye peucaant procedures as outhned m AC43.13-lh. tnspect both flanges of the man sparand the angle-doubler In the curved ama Just below the vemcal stabtiizer skm for possible cracks.Also inspect the Joggle III the angle-doubler beueatb the slun and just aft of the mam spar flanges forpossible c r a c k s ,St3? Flprc 1.1

4. Check the spar and angle-doubler flanges for rucks which could possible develop mto cracks

JOGGLE AREA

ISSPECTION AREAISSPEC-T BOTti FLASGES

I'age 4

a/14/97 AC43-204Appendix R

Service Ins t ruc t ions N O . 0530-134, Rev. I

CAUTION

If any cracks are found, contact Parts and SeMCe Operations. Beech Arctaft Corporanon,Wicmm. Kansas. 6i201. and report your findtngs for evaluaaon before proceeding w1t.h Par-tII.

PART b. If the doubler rep= IS made follownng detecaon of a cracked spar or qie-doubler. thefoBomng mspecaon must be made at each 500 hour interval thereafter und the vemcal jtabllizer hasbeen replaced.

1. Remove the tail cone.

2. Lower the front of the horizontal stabilizer to ga.m the greatest accessibil i ty to the vemcalstabilizer mam spar where it is attached to the ax-plane st~ctum.

3. Through the tail of the airplane. inspect both flanges of the main spar and the angle-doubler mthe curved area just below the upper fuselage skin (Figure 1) with the md of a 3 to 5 powermagnifjbg glass.

NOTE

R e m o v e t h e h a n d l e f r o m t h e magrufymg g l a s s a n d f a b r i c a t e atemporaq hand le approxunately 23 inches long o f wood o r o the rs u i t a b l e material. M o u n t t h e mu-xx on one end of the fabricatedhandle at an approzumate 90” angle to the handle in such a manner asto hold it securely. (See Figure 2.1 The long handle will facilitate themspecaon through the tall opemng.

4. If no new cracks or tucks are found in the mam spar or the angle-doubler flanges. the tail conemay be reinstalled.

5. If new cracks of nicks are found. proceed with Part II for repair

REMOVE THE HANDLE SHOW AT RlCHlAND MOUNT Oh’ A TEMPORARY HANDLEAS SHOW AT LEFT

(WOOD, HAMILE

SIZE AND SHAPE

Page S

AC: 43-204Appendix B

8/14/97

Semite Ins t ruc t ions No . 0530-134, Rev. I

P.kR.T II REP:UR

1. If mcks are found III the spar or angle-doubler flanges. they should be sanded smooth to lessenthe posslbhty of crack development.

2. If cracks are found in either the spar flanges or m the angle-doubler flanges but not IKI both onthe same side. to a m,zumum depth of .25-mch. a repax may be made to the vertxal stabil izerassembly as follows.

a. Shp a stainless steel shim between the spar flange and the angle-doubler flange to preventdamage to the adjacent flange and grind out the crack. Leave a smooth edge and flair the area outto the normal flange width. (Figure 3.)

b. Fabricate and install two doublers from .125-inch by 5.0.inches by 30.0-inches and two shimspacers from ,025.inch by 2.0-inches by 12.0-inches, 2024-T3 aluminum alclad, as shown in Figure 3.

c. Install one doubler and one shim on each side of the verttcal stabilizer as shown m Figure 3.Remsdl t-he rivets whrch were removed in Part 1 for mspecaon of the doublers.

d. Starurq fern a point approamatcly ?J-mches forward of the vcmcal stabilizer mam spar ‘andaft from rhat potnt. drill out all rivets wmch attach the vertxal stabthzer/fuselage angle-fainng to thefuselage.

e. \ieasure the width of the doublers at the vemcal stabilizer skm lower edge. (See Figure 3.) Therectangular cutout m the upper fuselage should be lengthened to at least 1.5.Inches longer than theu<dth of the doublers to a l low c learance be tween the s tabi l izer and the dorsa l faring durmgmstallnuon of the stabtllzrr.

NOTE

It Itlil~ ix rleccssarl; to relocate the small angle at the afK of the cutoutm order to achieve the necessary cleannce for the doublers.

f R~lnst~ll the vt~rt~cal stabthzer as dcscnbed 111 Chapter 55-30 of the !Haintenancc \ianual.

NOTE

(‘heck the clearance betsveen the forward surface of the man spar andthe bulkhead. If the two surfaces am not flush the gap should be5tumrned. (Shims may be fabricated locally from alutnmum stock.)

q. Form the verucal st3blllzer:fusrl;ige angle-faxme around the doublers and reinstall the rivetswh1c.i: :~r’re removed 111 step d. I<etrlst?ll screws to attxh the angle-falnng to the vertical stabthzer.

t1 I..~~lnsr:lll and rf,ng the nodder and tnb per Chapter “7-20 of the 51aintfnance 11anual.

:i T!:e preceding doubler mstallatlon I> to bt rnndc on all aff’rrtcd nlrplnnes ior the vc~rtlcnl it.xblltzermay he replaced with a new P/N 115~6~~WX-6~)5 vrsmcal smbtllzcr assembly), regardless of whethercracks are noted or not with the foilowtng exceptlon

Page 6

8/14/97 AC43-204Appendix B

Service Instructions No. 0530-134, Rev. I

l LEAVE EXlSTlNC FASTENERS It-STALLEDAND ADD 16 EA CRIZJ9.54 FASTENERSON EACH SIDE AS SHOWN 2-l

. REMOVE EXISTING MS20426ADS FmEMRSAND REPLACE WITH CR2249.Sd AND ADD6 EA CR 2249.S+5 FASTENERS ON EACH SIDEAS SHOWN

MLFRONT

OFANGLE-DOUBLER

UUUUUK

h MEASURE THIS DISTANCE1.50 R

AREA CFWXlNG OCCURRED

10 EQUAL SPACES

SHIM As RCQ.BElWEEN SPARAND BULKHEAD

INSTALL SHIM-SPACER (2 REO.),025 X 2.0 x 12.0 2024-n ALU?4 ALCLADBETWEEN DOUBLER AND SPARAND BELOW STABILIZER SKIN LINE

8 IM)ICATES EXLST’ING RIVETS

Page 7

AC 43-204Appendix B

8/14/9'7

Service Ins t ruc t ions No. 0.530-134, Rev. I

If cracks are found m both the spar and angle-doubler flanges on the same side and/or the cracksextend LIEU) the nvet holes or mto the ndlus of the spar or angle-doublrr. the vtlrt~al btabdlzerassembly must be replaced. Removal and remstallat~on of the rudder and the vertical stablilzer aredescribed m Chapter 27.20 and 5530 respecuvely of the Sxntenance !4anual. renggmg of the rudderand tab 1s described in Chapter 27-20 of the Maintenance Manual.

RECORDCOMPLIANCE: U p o n c o m p l e t i o n o f these Serwce Instruc~ons. make a n appmpriaw

nmntenance record entry.

I?age 8

8/14/97

APPENDIX C. PRATT & WHITNEYENGINE GENERAL -INSPECTION/CHECK - 00


Task 72-00-00-990-004 Paras 1-4Task 72-31-82-990-001Task 72-31-82-990-002Task 72-31-82-200-003

Retyped with permission of Pratt & Whitney.

AC 43-204Appendix C

Page 1

AC 43-204A p p e n d i x C

8/14/97

I


ENGINE G E N E R A L - INSPECTION/CHECK-O0

1.Task 7’.00-00-990-004Prelimlnal-v Instruct10ns

CAUTION: TITXVIUM WELD5lENTS AND ASSEMBLIES SHOULD NOT BEPROCESSED THROUGH TRICHLORETHYLENE DEGREASERS ORANY CLEANER CONTAINING CHLORIDES IN ORDER TO AVOIDP O S S I B I L I T Y O F S T R E S S C O R R O S I O N A S S O C I A T E D W I T HENTRAPMENT OF CHLORINE-CONTAINING MATERIALS INTIGHT FITTING AREAS. THIS RESTRICTION i\LSO APPLIES TOPARTS SUCH AS TITANIUM DISKS OR HUBS CONTAININGINSERTS, SLEEVES, OR PINS. DISKS .MUST BE DEBLADEDPRIOR TO CLEANING AND PRIOR TO FLUORESCENTPENETRANT OR MAGNETIC PARTICLE INSPECTION.

A.

H.

Thorough and intelligent inspectaon of all engme parts is one of the controllmg factorsin eff%lent and dependable mutenance. and too much emphasis cannot be placed onthe importance ofcareful inspectaon and the decisions lt involves. Inspecuon personnelmust be thoroughly fanuliar WI& mscrucnons In tlus chapter. m the requlrcments ofthe Standard Pmcnces Manual and in Reparr Secnoxx.

Af&r engme 1s disassembled and cleaned, arrange all parts of engme on lnspectlontable so that inspector can Judge the condition of engine as a whole and can readilymake reference to other engme parts wmch may have been affected by a worn part.In this way, lt wtll often be possible to deterrmne at once the cause of any abnormalwear.

2. Records and Llrmts

A. During lnspecuon, keep a record of the condition of all parts and a record of all fits.clearances. a n d spring prpssunxs. R e f e r t o t h e specfic f i t s a n d c l e a r a n c e srequuements m the appropriate InspectlonCheck secuons of tis manual for properInnits Attach a tag, mdlcaw that replacement IS necessary. to any part which 1sfound to be unfit for further seMce. Attach a tag descnbmg necessary refurbishmentto any part which reqiures repair If refurbishment will affect a fit or clearance. tagmust remam with part until final assembly and must be marked wth a warning tocheck fit or clearance.

B. When a new part is to be Installed and It IS important that It be ldentfied as to en@nenumber or posItIon III ezwe: mark It by appropnatr method described m .Marlung ofParts m Standard Practxes ,Manuai.

(’ \i’hen makIng o u t msprctaon reconis o r rc~1~ort.s. use only dcscnptlvv xvords w h i c haccurately quahfy cxxnng coudluons. III order to elunmarc cotislon and to m=n1;11nconsistent tennology. the vnnous physical condltlons and the detennlnatlon of theusual causes of wear or damage to tLnqnt> parts whlcb rmght be enrountercd duringmspcc‘oon a r e d e f i n e d m t h e Fhys~cal Jnspccuon Srct2on o f .Standard Pract3crs a11 a nu a1

E F F .tiLPage 802

?age 2

8/14/w AC 43-204Appendix C

.t

Pratt & WhitneyPW4000 SERIES ENGINE MANU.U (PN 50x443)

E N G I N E GENEFLAL - INSPECTION/CHECK.00

Task 72-00~00-990-004:D. If mspection reveals it necessary to replace a fitted spacer. tag spacer to indicate tha

replacement must be made with a part of correct classtficatlon at assembly,

General lnspwhons

A. See Standard Practices Manual as follows:c 1) Physical Inspecuon(2) -Magnetic Partrcle Inspecnon13) Fluorescent Penetrant Inspection(41 Surface Treatments(5) Welding(6) Gage Inspection

Corrosion Prevention AfIer Inspection

A. Equipment and Materials.

Item No. Desrmabon

P95-035 Corrosion Preventlvc OtliAM. 3065)

B. A&r mspecaon, whenever It I S deemed tha t su f f i c i en t t une wLl e l apse be fo rereassembly to allow damage to parts from corrosion. cover all unprotected surfaces ofmagnesmm a n d s t e e l p a r t s . , o r a n y p a r t s vntb wmch corrosion dficulnes a r eexperienced. urltb Corrosion Prevenave Oil (PO5-035). Unless the parts are otherwtsepreserved for longer periods of time, they should be recoated with Con-oslon PreventionOil (PO5-035). every four days.

E F F UL.Page b03

Page 3

AC 43-204Appendix C

a/14/97

STAGE 1 LPC BLADE ASSEMBLY - INSPECTION/CHECK-00

1.Task 72-3 l-82-990-00 1.InspecnonCheck Part Number Index State 1 LPC Blade Assemble

A. Inspecuon Funcuonal Arrangement

(1) InspectloniCheck.01 t h r o u g h InspectiomCheck-06 c o n t a i n p r o c e d u r e s f o rcomplete inspection of Stage 1 LPC blade assembly. Inspection func~on a&applicability for this part are shown in Table 801.

INSPECTION/CHECK INSPECTIONiCHECK INSPECTION/CHECKNUMBER CATEGORY APPLICABILITY

JO- 1 PreinspectionPreparanon

-0-2 Non-destructaveInspecnon

-03

-04

Visual inspectlon

DunensionalInspection

-05 Functional CheckInspectnon

-06 InspectionPostrequisites

Inspection Functional ArrangementTable 801

B. InspecuoniCheck Part Sumber Index

Applicable

Applicable

Applicable

Apphcable

Applicable

Applicable

11) Table 802 i s a listmg of par t numbers and appropr ia te InspecnonXhecknumbers . Refe renced service bulIehns a re l:stcd fo r pa r t s i n t roduced o robmned by ser.nce bullets incorporation.

PART?XMBER

52A12153A32 1

SERWCEINSPECTIOXCHECK BULLETIN

01.02.03.04.06 PW4ENG 72-13201.02.03.04.06 PW4ENG 72132

Inspection/Check Part Number IndexTable 802

E F F ALLPage 804

Page 4

8/14/97 AC 43-204A p p e n d i x C

Pratt & WhitneyPW4000 SERIES ENGWE MANUAL (PN 50A443,

STAGE 1 LPC BLADE ASSEMBLY - INSPECTION/CHECK-O1

1.Task 72-31-82-990-002:Preinspection Preparation - Staqe 1 LPC Blade Assemblv

h Prereqtusites

(1) See InspecoonCheck-00 (Task 72.31-82-990-001~ for funchond arrangementand part number applicability.

B.

C.

Equipment and *Maten& Requu-ed . None

Procedure

See Figures 801. 802 and 803.

W A R N I N G T O A V O I D P O S S I B L E I N J U R Y T O H A N D S . G L O V E SSHOULD BE WORN WHEN HANDLING BLADES.

CAUTION NICKS LN LEADING AND TRPJNING EDGES BECOMEINCREASINGLY CRITICAL THE CLOSER THEY ARE TOROOT OF BLADE. THEREFORE. ANY INJURY TO THATPORTION OF BLADE FROM PART SPAN SHROUD TOPLATFORM M-UST BE TREATED WITH EXTRE,ME CARE.

(li Folloulng mstructlons are standard mspecnon cntena wbnch apply throughoutinspection procedures.

(a) Blade lirmts are evaluated from a standpomt of structural mtegnty.T h e u s e o f a s u b s t a n t i a l n u m b e r o f b l a d e s r e p a v e d t o o r n e a rmaximum hrmts. or use of blades havmg many repau-ed areas. maya d v e r s e l y a f f e c t c o m p r e s s o r efficiency a n d t h e r e f o r e engmeperformance.

tb) All blade surfaces must be smooth and all evidence of previous leadmgand txuling edge rep- should be smooth with a mxumum edgethickness as shown tn Figure 802 mantarned.

(C) AU blade lmuts are based on ong~nal edge contour, therefore, allblends in one location are cumulahve. For example. if blend depthlimrt is made, no further blend nor the sum of several future blendsmay e x c e e d t he maxxnum b lend dep th a t t ha t location Blendsdu-ectly opposite one another on leachng and trailing edge are alsocumulanve and must not exceed m-mum depth of smgle leadmg ortrting edge blend.

IdI Ma?umum d e p t h b l e n d s o n l e a d i n g a n d tra&ng e d g e s m u s t b eseparated by rmmmum distance equal to mean chordal length of bladeSee Figure 803

Page HO1

AC 43-204Appendix C

g/14/97


OUTER PORTIONOF BLADE -,

LEADING EDGE

INNER PORTIONOF BLADE

--

BLADE TIP

\ PART SPAN SHROUD

icI

A I R F O I LROOT SECTION

PLATFORM AND BLAOEROOT SECTION

I

SHROUD TO AIRFOILRADIUS (4 PLACES)

FRONT AND REARSHROUD RADIUSAREA IFOUR PLACES)

TRAILING EDGE

PLATFORM TO AIRFOILRADIUS IALL AROUNDBLADE)

j- PLATFORM SEAL

Blade hea NomenclatureFigure 801

[Task 72~31-82-990-002)

EFF .ULPage 802

Page 6

8/14/9’7 ~~43-204Appendix C

Pratt & WhitneyPW4000 SERIES ENGtNE MANUAL t PN jOA443)

STAGEl LPCBLADEASSEMBLY-INSPECTION/CHECK-O1

S E C T I O N A - A

L-A09681285

1.2.3.

Minimum Toting Edge Thickness As Measured At Index 2 To Be 0.020 Inch 10.51 mm).0.040 Inch i 1.02 mm1 - Measure Leadmq And Tralhng Edge Tbckness At This Dimetwon12.229 Inch (310.617 mm~. Mlmmum Leading Edge TtYckness As Measured At Index 2 To Be0.038 Inch (0.965 mm).

4. Mlmmum Leading Edge Thickness h Measured At Index 2 To Be 0.027 Inch (0.686 mm,.

Leadmg And Trtig Edgr 111wumTbckness L~rmts

Fqure 8021 Task 72 3 1.82.990.OO’L I

E F F .ULPage 803

Page 7

AC43-204Appendix C

8/14/97

STAGE 1 LPC BLADE ASSE>IBLY . INSPECTION/CHECK.01

I. -A0969

E F F ALLPage R04

?age 8

8/14/97 AC43-204Appendix c

Pratt & WhitneyPW4000 SERIES ENGINE MANUAL (PN 50A4-43;


tfl If two or more heavily blended blades arc found grouped together. ana t t e m p t s h o u l d b e m a d e t o redistiute these b l a d e s a n d theirmatctung blades evenly throughout rotor.

(g) Total Length of leading and tzGLing edge blends must not exceed fourmches (101.600 mm) and there must not be more than two blends tomaxrrnum depth limit per blade.

(2) Visually check leadmg and tra&q edges ofblade for damage whenever foretgnobject damage is suspected.

NOTE: Use of strong lights and mirrors as well as fingernails and fingempsmay a.rd in locanng damaged areas.

CAUTION. USE EXTREME CAUTION WITH ANY ELECTRICAL EQL!‘lP-MENT LV THE VICINITY OF BLADE. CONTACT WITHANY ELECTRICAL SOURCE THAT MAY PASS CURRENTTO BLADE SURFACE CAN CAUSE AJJ ARC BURN. ARCB U R N C A N R E S U L T I N L O C A L DEGRADATIOS O F,MATERLAL PROPERTIES AJJm CMCK INITWTION.

(3) When checking blades for foreign oblect damage visually mspect for arc bum.Arc burn IS evidenced by a small circular or semi-clrcuiar bead affected areaon blade surface that may contain shallow plmng, remelt or a crack. Bladesuntb arc burn are not acceptable for further semce.

(41 The followxq procedure is recommended for mspecnon of 1st stage bladeassembly after refurb&ment or repau.

‘a1 V i s u a l l y Inspect b l a d e using a bright hght. mm-on. a 3X glass .fmgertlps and fingerm&, specifically looktng for small depressionsthat interrupt surface contour. Refer to PW.4 Color Photographs forcondiaons that have been observed.

cb) Peerung tends to remove evidence of heat dlscolorauon and to smoothdamage. making It less visually apparent

IC) Elecmcal dlschxrge damage has been obsewed in two different forms-

1 Strong geomemc shapes such as ovals. crescents. or rectanglesdepressed intn blade surface rmght be caused by contact wttha rod or wre carrying an elecmcal charge.

C o a r s e linear mdicauons, typ ica l ly composed o f sma l loverlappmg craters or pits.

SOTS: Regardless of form. damage IS a local phenomenon.unhke emsion pimnq. and damage houndanes do norh a v e r a i s e d rnatenal a!, does d a m a g e f r o m forclanoh~rct damage

Page 9

A C 4 3 - 2 0 4Appendix C

g/14/97

D

STAGE 1 LPC BI-ADE ASSE>IBLY . ISSPECTIONiCHECK.01

151

(G)

Blades suspected of hanng elecmcal discharge damage must he removed fromZCI-.ICC immediately, and blue etch anodize-inspected to ronfinn damage.

CALTION. ELEC'iRICALDISC~GED~~GEISNOTREPAIK~BLEBY BLENDLh'G. THIS DAMAGE PRODUCES A LiEATAFFECTED AREA WHICH MAY EXTEND L? TO 0.060INCH (1.524 MM, DEEPER THAN VISIBLE DAMAGE. ANl.BLADES EXHIBITING THIS DAhtiCE SHOL;LD BERETIREDFROMSERVICE.

The blending procedures described hereln are intended to ensure that allsubsurface as weI.I as surface damage is removed. It is cntxaLIy importantthat the blending procedures be followed carefully whether performed in theshop or on the ~ng. Proper blending must be performed ua successive stages:Removal of the visible damage, condrmation by eddy curernt or fluorescentpenetrant inspection that all surface damage has been removed and, fmally.removal of additional material to ensure the Emoval or subsurface deformedmat&a).

Preparanon For lnspecuon

(1) Disassemble and remove attached p&s). Not Apphcable

(2) Remove surface treatments See Repay-06 (Task 72-31-82-300-006~

(3) Clean base material - See 72-31-00. Cleaning-01 (Task 72-31-00-100-001)

Page 806E F F .U.L

Page 10

H/1.4/97 A('43-204Appendix c

Pratt & WhitneyPW4000 SERIES ESGLUE MANUAL tPN 5OA443)


1.Task 72~31-82-200-003.Visual Inspection . Stage 1 LPC Blade Assembly

SOTE Comply w1t.h the followtrig procedures whenever foreign object damage is suspected,

x Prerequls1t.?s

11) See LnspecuorKheck-00 (Task 72.31-82.990-001) for funcuonal arrangementand part number appkcability.

(2) See InspecaonKheck-01 (Task 72~31-82-990-002) for general mspecaon data,

B; Equtpment And MatenaIs Required _ None

C. Inspect State 1 LPC Blade Assembly For Damage

See Figures 801 through 803.

\l) Inspect airfoii, except leading and edges for damage. Follownng typesof damage should be blended per rep--O2 (Task 72~31-82-300-0021 WI&~huts specified in Figure 801.

NOTE: Louts shown in referenced figure refer to maxunum matonal removalallowed during blending and not to actual depth of damage beforeb lend ing . Damage a t o r nea r maxunum Linus shown will not bereparable if blending will exceed these limits.

la) Sustatned mdentations with compressed maternal and raised edges.(b) Injuries with small radii or ragged edges.Cc) Tip curl damage.

!‘I Inspect leadIng and n&g edges for fomrgn object damage such as mcks anddents These defects must be blended per Repair-02 (Task 72.31-82-300-002).See Figures 801. 802 and 803. No cracks or tears are permrttod.

(a)

0)

ic)

Damage. not WI&~ cnacal area, should be blended ifit exceeds 0.020inch 10.51 mm1 depth.Damage, w~thm cntacal area. should be blended if it exceeds 0.005 inch(0.127 mmi in depth.Damage not exceeding 0.005 inch (0.127 mm) in depth need not beblended pmvtded material LS not torn

D. Adoli Root &coon Blend Lmuts

See Figure 803.

Page 11

AC43-204Appendix C

R/14/97

STAGE 1 LI’C RLWE tiSEI\IBLY . INSI’ECTION/CHECK-03

11

e-1 P L A N E Z

T A N G E N T

S E C T I O N A - ACtiOHO L E N G T H M E A S U R E M E N T

L - A l 0 5 7

Page 12

R/14/97 iii: 43-204Appendix C

1.‘7ti_

3.4

5.

6./i.

a.9.10.11.12.13.

Pratt & WhitneyPW4000 SERIES ENGINE MANUAL IPN 50A4-13,

STAGE 1 LPC BLADE ASSEMBLY - INSPECTION/CHECK-03

Blade TIP Blend Radius . 1.500 Inches (38.100 mmt MaulmumLeadmg Or Trailing Edge And Tip Blend Area - Blend To Be 0.750 Inch ( 19.050 mm) DeepMaulmum.19.515 Inches 1495.681 mm).Critical Area - Depth Of Blend To Be 0.250 Inch (6.350 mm, .Maxlmum Except For .41rfod RootSechon. See Index 5 Dimension1.000 Inch (25.400 mm) - Damage In Airfoil-To-Platform Radius .kea Cannot Be BlendedExcept Per krfoil Root Section Blend Limits In Paragraph D.No Damage Or Blending Perrmtted In Shroud-To-Purfoil Radius Or Platform-To-&rfoll Radius,Concave And Convex Blade Surface Blend Area . Depth Of Blend In This Area To Be 0.030Inch 10.762 mm) Maximum (Round Bonom).Leadmg Edge Blend Area - Depth Of Blend To Be 0.500 Inch ( 12.77 mm) Ma.ulmum.6.300 Inches (160.020 mm118.500 Inches (469.900 mm)22.500 Inches (571.800 mm)0.500 Inch (12.700 mm). Pour Places.,Mimmum Chord Length To Be 6.950 Inches (176.530 mm) Within 6.390 Inches ( 160.020 mm)Of Leadmg Edge Platform. Chord Length Must Be Measured Tangent To Blade Leading AndTmhng Edges And Parallel To Phase 2.

NOTE Damage which afkts both Index 1 and Index 2 must be blended by combining bothlu-mts to produce a smooth blend.

Key To Figure 801

a/14/97 AC43-204Appendix D

APPENDIX D. PRATT & WHITNEYENGINE GENERAL -INSPECTION/CHECK - 01A


Task 72-00-00-990-009

Retyped with permission of Pratt & Whitney.

Page 1

ftC 43-204A p p e n d i x D

8/14/97

SAAIPLE INSPECTION PROCEDURE

1.Task 72 iK) i)o-990-009:General Borescope Inspecnon Procedures And Borescope Access Port c.%Pj Data

A Equipment hd Materials Required

Special Tools:PWA 85572-l Compressor Rotating Kit (Foot Operated, Optional

PWA 85572.2 Compressor Rotating Kit (Hand Operated) Opnonal to PWA 85572.1

Speed Borescope Equipment:See Paragraph 1. C. Special Borescope Equipment.

Consumable Materials:

Item No. Designation

PO3-00 1 Oil. Engine tPWA 5218)PO6-003 Compound, Anngalling tPWA 586-3)

Expendable Parts:PARTS CATALOG REFERENCE

B.

AccessPort

ThruFan

U-1

AP-2

XP- 3

EFF. .XLL

PART NAME QUAUTITY S E C T I O N

Packing 1 72-61-00

GeneralSee Figures 801 through 804 and Table 801.

AngularLocationClockwiseFrom Rear

Part{ s) ViewableFor Inspection

1st C-Vane1st C-Blades

245” ( 11 Rear of 4th C.BladeFront of 4th C-Vane

“33” Rear of 5th C-BladeFront of 6th C-Blade

“31” Rear of 6th C-BladeFront of 7th C-Blade

Borescope Access Port ( XI’) DataTable 801

FIGURE ITEM

8 160

RecommendedMauunum ProbeDiameterIncW(mm J

. _ . . .

.270/6.8

.270/F 8

Page 802

Page 2

8/14/97 Ac43-204Appendix D

AccessPort

AP-4

ti@lltiLocauonClockwiseFrom Rear

127”

AP-5 214”

AP-6 98”

AP-7 80”

AP-8 277”

A.P-8 45”128”172” (2)225”338” (3)

AP-9 93”

.AP- 10 139”

4-W-11 215” 14)

TtU-UExhaustCasestruts

Pratt & WhitneyPW4000 SERIES ENGINE MANUrU i PN 50A443 )

ENGINE GENERAL - INSPECTION/CHECK-OlA

Part(s) ViewableFor Inspection

Rear of 8th C-BladeFront of 9th C-Blade




Fuel NozzleCombustion Chamber1st T-Vane

Fuel NozzleCombustion Chamber1st T-Vane

Front of 1st T-VaneFront of 1st T-Blade

Rear of 2nd T-BladeFront of 3rd T-Blade

Rear of 1st Turbine BladeFront of 2nd Turbine Blade

6th T-Blade6th T-Vane

Recommendedhhxxnum ProbeDiameterInchAmmJ

.27W6.8

.270/6.8

.270/6.8

.27Of7.8

.444/11.3

.444/l 1.3

.444/l 1.3

.27W6.8

.270/6.8

.444/l 1.3

_-_- __-_

NOTE. i 1) Fle.xible probe requved at this access port topuonal all other ports,.(2) Right angle eye piece required at this access port.13) Right angle eye piece desirable at this access POI-L‘4) Optional borescope port location

Borescope Access Port CAP) DataTable 801 (Cont~nued~

E F F ULPage HO3

Page 3

AC 43-204Appendix D 8/14/g?’

P%‘4000 SERLES ENGLUE M.LLC'UIU.IPX 50~+131

ENGINE GENERAL- INSPECTlON/CHECK-OIA

4!i”1280

BOO

172’

(AP-61 IAP-71DIFFUSER CASE \

14TH STAGE STATOR

TRANSITION DUCT (LPT INLET)

n\

‘-4390 COMBUSTION CASE i-ETH STAGE STATOR

IAP-lOI I

93O

12TH STAGE STATOR 127O

L A4366IAP-91 LAP-41

980

lAP-61

Borescope Access Porn 1 Hlqht Side)Figure 501 (Sheet 11

(Task 73-00-00 900-009~

E F F ALLPage 804

Page 4

8/14/97 AC43-204Appendix D

ENGINE GENERAL- INSPECTIONXHECK-OIA

233’(AP-21

/-5TH STAGE STATOR

215O

IAP-11 OPTIONAL)

r2ND STAGE VANE

4TH STAGE STATOR

(2.5 BLEED VALVE OPENING)

6TH STAGE STATOR

2450 kJ

(AP-II

IA P - 6 DIFFUSER CASE

LOCATIONS

L 1OTH STAGE STATOR

2140 L -A0634(AP-51 0668

Borescope Access Ports ~Rlght Side JF~gum 801 (Sheet 11

(Task 72-00-00-990-0091

EFF ALLPage 805

Page 5

AC 43-204Appendix D

8/14/97

Pratt&WhitneyPu'~ooo SERIES ENGNE tiWtlL(PN 5OA443,

ENGINE GENERAL - INSPECTION/CHECK-OIA

APll(OPTIONAL)

APZ-7. 9, 10 . . . . . . . . . . . . . . . . . . LOW MAGNIFICATION RIGID BORESCOPE.(.270 INCH16.8 mm BARREL DIP, MAX.)

AP8, 1 l.._..........._.............HIGH MAGNIFICATION RIGID BORESCOPE.(.444 INCkU11.3 mm BARREL. DIA. MAX.)

AP-1 ,................................ FLEXIsLE BORESCOPE.(OPTIONAL FOR i.270 INCH168 mm CABLE DIA. MAX.)APZ-71

T,,R,, FAN...-...;. . . . ..__..... FLEXIBLE BORESCOPE

(STG. 1 VANE. ( ,270 INCH/ 6.8 mm CABLE DIA. MAX.1

STG. 16 BLADE1-OR-

LOW MAGNIFICATION RIGID BORESCOPEI 270 INCH/ 6 Bmm BARREL DIA. MAX.) L-A0640

0490

Borescope Access Ports (Right Side)Figure 801 (Sheet 2)

(Task 72.OO-OO-990.009)

EFF ALLPage 806

I?age 6


ENGINE CEhT%A.L.- INSPECTION/CHECK-OlA

(SCAVENGEPUMP DRIVE1BEARINGH O U S I N GA S S E M B L Y

IL MANUAL CRANK PAD COVER

MAIN GEARBOXFRONT VIEW

L - A 0 6 4 60688

Manual Cnnk Pad LocanonsFigure 803

(Task 72-00-00-990-009~

EFF tULPage 807

Page 7

AC 43-204Appendix D R/14/97

PVv.4000 SERIES EIVGLYE If&-VU (Ph’ 50A4431

ENGIhT GEh’ERAL - INSPECTION/CHECK-OlA

BOR ESCOPE PROBE

COWL CLEARANCE

PROBE OVERALL LENGTH

PRIMARY GAS PATHPROBE WORKING LENGTH

, - I N S P E C T I O N D E P T H

,/‘ L -A0650

Borescope Probe \Voriung SpecficauonsFqure PO4

(Task [email protected]

EFF .tiLPage 808

Page 8


ENGINE GENERAL. INSPECTION~CHECK-OlA

WARNMG BORESCOPE INSPECTIONS MUST BE PERFORMED IS APROTECTED AREA. IF INSPECTIONS ARE PERFORMEDIh’ \-ET WEATHER. APPROPRIATE PROTECTIOS 1lUSTBE USED TO PREVENT DAMAGE TO EQUIPMEST ORPOSSIBLE ELECTRICAL SHOCK TO THE OPERATOR.

CAVTIOT BORESCOPE INSPECTION LIMITS ARE DERln-ED FRO>1TESTLXG A N D STRUCTUR4L ASALYSIS. CONTINL-EDSER\?CE OF PARTS AT OR h’EAR MAXIML7M LIMITS hiAN O T B E E C O N O M I C A L L Y S0Uh-D B E C A U S E O FPERFORMANCE LOSS OR REDUCED PART LIFE.

(1) The provisions for borescope inspection of the engine represent a sign&cantaid to effecuve tnamtenance. Borescope access IS incorporated at 15 locations( 16 for engmes utilizing AP-11) along the engine gaspath. allowing for detiedexamination of critical internal engine areas.

NOTE: Borescope ports used in the folIowing procedures are identified by their“Ap” (access port) designation as shown m Figures 801 and 802.

(2) The regular inspecnon interval referred to in this procedure 1s obtamed fromthe Maintenance Planning Guide. The reduced inspecnon interval is set athalf that value. These inspecoon intervals may be adjusted based on operatorexperience and consultation with the local regulatory agency.

C. Special Borescope Equipment

CAUTION : T E M P E R A T U R E S I N A R E A S T O B E B O R E S C O P E DSHOULD BE PERMITTED TO COOL TO BELOW 150°F(65.6”C) FOLLOWING ENGINE OPERATION. DAMAGEM A Y R E S U L T T O B O R E S C O P E E Q U I P M E N T I FE Q U I P M E N T I S E X P O S E D T O GASPATH O R M E T A LTEMPERATURES LV EXCESS OF 150°F (65.6”C). AS AGUIDE - LF ADJACENT CASES ARE TOO HOT TO TOUCHCOMFORTABLY, INSPECTION SHOULD BE DELAYED.

(1)

(21

Borescope mspecnon equipment for the PW4000 engine should sat&y therequirements of CTE 6181 as published by Support Equipment Engmeenng,Prat t 8; titney. Commercml Products Division. Middletown. CT 06457.U.S.A.

Specification CTE 6181 identifies the equipment and associated hardware(such as power source, hght cables, adapter etc.) required during borescopehspection and sets the quality and functional standards for this equipment.In summary the following borescope equipment is recommended.

a) Low magrufxatton ngid borescope ,......... Ap2-7, 9(0.270 inch(6.8 mm) barrel diameter maximum I

b) High magmticatton ngid borescope ,......... AP8. 11,0.444 inch/c 11.3 mm I barrel hameter mzumum 1

Cl Flezuble borescope . . AP- 1. 1 op~onal for APL?.; 110.270 inch/f6 6 mm 1 cable diameter maxunum I

E F F A L LPage 809

Page 9

AC 43-204A p p e n d i x D

a/14/97

Pratt & WhitneyPW4000 SERIES ENGINE MA..AL (PN 5OA443)

(3) Optional borescope eqmpment and sizes are also provided m CTE 6181 toenhance the borescopmg capability and ease the task for the mspector. Theseitems range from clampmg equipment to hold the borescope ln posltlon CQopacal video equipment to view and videotape record the borescopmg sessionfor later m depth review.

D. Rotation Of High Pressure Rotor During Borescope LnspectlonSee Figure 803.

(1)

(2)

(31 Install manual crank pad cover.

Full 360 degree borescope inspection of the high pressure rotor can beaccomplished usmg the r o t o r - c r a n k i n g provision on the gearbox.

Remove manual crank pad cover (Figure 803) on main gearbox.

CAUTION: DO NOT REMOVE THE GEARBOX (SCAVENGEPUMP DRIVE) BEARING HOUSING ASSEMBLY.I N S T A L L A T I O N O F T H E B E A R I N G H O U S I N GA S S E M B L Y I S D I F F I C U L T . INCORRECTLVSTALLATION WILL DtiIAGE THE BEARING.

(a) Remove two bolts and two washers securing manual crank pad cover.Using PWA 85768 Puller, remove crank pad cover. Discard packingfrom stem of cover.

ib, Attach PWA 85572-l Foot Operated Rotator or PWA 85572-2 HandOperated Rotator to N2 rotator pad. Make sure socket drive in theangle dnve adapter aligns correctly w?t.h hex end of oil pump idler gearm gearbox and secure using two lf4 - 28 cap screws provided. Attachan ar supply to the pneumaac motor. Actuate usmg foot or handcontrol.

KOTE: Use of motor-dnve umt will free operator to use both hands toposlnon and adjust the borescope. I t is recommended thatrotBnon be stopped as each rotor blade is poslnoned properlyfor mspecnon. This ~LLI allow thorough. detailed appr;ilsal ofeach blade’s condlnon.

CR1 Insmll paclung lubricated wit-h Engme Oil iPO3-001). mgroove on stemof manual crank pad cover. Install cover and secure wth two washersa n d t w o b o l t s lubricated ~lth Anugallmg C o m p o u n d L PO60031.Torque bolts to 62 72 lb-m. (7.005 . 3.135 N.mj.

Page 80 1CE F F A L L

1?age 10

A

8/14/97

APPENDIX E. DC-9 SERVICE BULLETINSAMPLE INSPECTION PROCEDURE

ACAX-204Appendix E

Excerpts of Douglas Aircraft Company McDonnell Douglas DC-9Service Bulletin Alert. Bulletin A53-232, March 28/90.

Retyped with permission of Douglas Aircraft Company McDonnellDouglas

Page 1

AC 43-204Appendix E

R/14/97

SAMPLE VTSU.V.INSPECTIOK PROCEDURE

D O U G L A S A I R C R A F T C O M P A N Y

M C D O N N E L L D O U G L A S ALERT

SERWCE BULLETINFUSElACE - Main Frame - Inspect/Rep~ Aft Fuselage Ventral Pressure Bulkhead Tee.

S U M M A R Y

T h i s A l e r t Semce Bullean I S adected b y F e d e r a l Avlanon AdmuusnauonAirworthiness Direcnve No. 99-16-12 Amendment 39-6287. effecnve September 7.1989.

This Alert Service Bulletin is apphcable only to aircraft equpped with ventral aftpressure bulkhead wluch have accumulated 35.000 or more landings.

Replacement of all six aft pressure bulkhead tee sections with new unproved parts perth i s Alert Service Bullean consututes c los ing acaon for the repeutive inspect ionrequirements of this Alert SeMce Bullenn

This Alert Service Bulletin supersedes but does not cancel the requn-ements of DC-9Alert Service Bulletzn xXJX#L Only aircraft listed in this Alert Senlce Bulletin thatare contamed m the AKectavlty of Alen Service Bulletin XX-m are affected by ttuSconnngency.

1.

This Alert Service Bulletin 1s tssued as a par~al record-type change. A seance reworkdrawmg or aperture cards are furrushed m heu of illust.ta~ons.

Planrime Information:

h FlfTeca~ltv~

111 An-craft Nfected

DC-g. Senes 10. 20. 30. 40. 50. and C-9,DC-9-81. .R2, and -83 (MD-RI, -nl’, and -11.7’

Bulletin XX-XXX hlarch 28'90

age 2

8/14/97 A(: 43-204Appendix E

SAMPLE VISUAL INSPECTION PROCEDURE

lFSY’1FLY F L ’ S 1 FSN) Fz’s (FSNI m m- - m IFSS) FL-S IFSS‘I

1160 149257r 1185 1492651 1210 (49291; 1235 149236) 1260 (49415) 1285 i49394r1161 i 49258) 1186 (49250) 1211 (49292) 1236 149383) 1261 149402) 1286 (4939511162 (492591 1187 149288) 1212 (49293) 1237 149384) 1262 i49216) 1287 14938611163 1492631 1188 149206) 1213 149294) 1238 492661164 (492691 1189 (49207) 1214 (492953 1239 492671165 (492701 1190 149208) 1215 1492961 1240 494251166 (49271) 1191 (49209) 1216 (49297) 1241 494281167 149272) 1192 (49210) 1217 (49298) 1242 49429)1168 (492731 1193 (49289) 1218 149299) 1243 492131169 (49252) 1194 (49280) 1219 (49300) 1244 493851170 149202)1171 (49264,1172 (49188)1173 (49189)1174 (49203)1175 (49286)1176 (49287)1177 (49231)1178 (49232)1179 149204)1180 149190)1181 (49277,1182 (49164)1183 (49’278)1184 (49205)

1195 149290)1196 149366)1197 (49367)1198 (49368)1199 (49369)1200 149281)1201 (4937311202 (49211)1203 (49233)1204 (49234)1205 (49379)1206 (49370)1207 (49371)1208 (4937411209 (49284)

1220 149301)1221 149302)1222 149303)1223 (49304)1224 (49355)1225 (49380)1226 (49305)1227 (49306)1228 r49307)1229 (49308)1230 149279)1231 149381)1232 (49382)1233 (49212)1234 (49235,

1263 '494211 1238 14938711264 (49422) 1289 14932411265 (49318) 1290 149352)1266 (49319) 1291 149443)1267 (49320) 1292 (49501)1268 (492171 1293 (49478)1269 (49390) 1294 (49358)

1245 (49214)1246 (49309)1247 (49310)1248 (49311,1249 (49312)1250 (49356)1251 (4935711252 (49372)1253 (49215)1254 (4942011255 (4931311256 (49314)1257 (49315)1258 (49316)1259 149317)

1270 (49391 i1271 (49416,1272 (49392)1273 149321)1274 (49218)1275 (49363,1276 149364)1277 149365,1278 (49417)1279 (4939311280 14932211281 149323)1282 (49282)1283 (49423)1284 149424)

1295 (4932611296 (49327,1297 (49479)1298 (4948031299 i49283)1300 (4950211301 (49328,1302 149329,1303 149436)1304 149440)1305 14939611306 14933111307 149332,1308 14948111309 149482,

ia) ODerator and Aircraft Number:

This modification will be incorporated pnor to dekvery on allapplicable DC-g. Series MD-80; MD-88 aircraft, manufacturersfuselage number 1310 and subsequent

12) Spares AtTected:

None:

B. Reason:

Eight operators have reported cracks in the ventral aft pressure bulkhead attach wesechons on eight au-craft. The affected aircraft had accumulated between 45,492 and60,969 landings when the cracks were found. The predonunant areas of cracks are atthe upper pylon attach angle between longerons 13 and 14 (6 cases) and lower pylonattach angle between longerons 16 and 17 12 cases,. Longerons 2, 7, 11. and 18 eachhad one crack. The cracks exhibited similar behavior. cracking clrcumferennallyapproxunately 1.9 Inches outboard of the Inboard edge of the upstanding leg of thebulkhead attach tee sections. Cracks were found up to 8.8 mches In leqgth. .tialys~sof fouled parts revealed that the cracks irutmted at mulnplc sites on the foww-dsurface of the upstandlnr: lttr: of the tee as the rrsult of fatigue due pnmnnil, TobendIn< loads lfcracks nre not detected and repawd. thpy could progress to the p(jlnr

Page 3

AC 43-204Appendix E

R/14/37

StLJlPI,E VISUAL INSPECTION PROCEDURE

that rapid decompression could occur. Iuspectlon o f h i g h c y c l e a i r c r a f t a n daccomphshment of repau-s based on condlnon ~111 allow conunued flight operation.

C. Descnnaon:

T~s Service Bulletin accomphshes the following on the fuselage aft pressure bulkhead.

Inspecuon from Aft Side of Bulkhead

Performs visual inspections for cncked af? pressure bulkhead web-to-fuselage teesections around entare per iphery of the fuselage f rom af t s ide of bulkhead andaccomphshes the followmg:

Condition 1 (No Cracki

Repetttively visually inspects for cracks from aft side ofbulkhead at intervals specifiedin Compliance paragraph.

Conditron 2 irrnck 1

Replaces cracked tee section with new or improved part and repetitively visually andfor cracks from aft side of bulkhead at tntervals specified in Compliance paragraph.

D. Comphance:

I t i s recommended tha t imtial mspectron/repalr of a.fI pressure bulkhead tee beaccomptished as follows on aircraft having logged over 35,000 landmgs.

Xccumulated Landings

35,000 to 49.399

Inihal Inspection

1Vith.m 1500 landmgs from issue date of &usSewn Bulletm.

50.000 to 59.999 LVithm 100 landrngs from issue date of thisSwwce Bullem

60.000 and over ‘A’ithln 300 l andmgs f rom issue da te o f thrsSer-vrce Bulleun.

When aft prrssure bulkhead tee secuon IS replaced wttb new Like part, the rcpeutivemspecuon f o r t h a t section o f t e e m a y b e dlscontmued untal t h e a i r c r a f t h a saccumulated an additional 35.000 landings at which tnne the repetttrve mspecnon forthat section of tee are reinstated along with the ongoing repetitive inspectaons of theremaimng ongmal Sections of tee.

When aft pressure bulkhead tee secuon 1s replaced with new Improved part per thisSenqce Rullcnn. the repetlnve mspecuon for &;lt s;ctcuon of tee may be dljcorlunucdas thts consututes closmg acuon for that secuon of tee. Perform the recommendedrepetltivc mspecDons on the remammg ongmal tee secuons.

Bulletln XX-XXX March 28/90

Page 4

8/14/97 AC 43-204Appendix E


Replacement of all six af? pressure bulkhead tee secaons with new unproved parts perthis Alert SeMce Bulletm constitutes closing action for the inspection requirementsof ths Alert Serwce Bulletin.

It is recommended that repetitive inspechon/repau of aR pressure bulkhead tee beaccomplished as follows.

Insnecuon from Aft Side of Bulkhead

It is recommended that repetitive visual inspection of top and lower areas fromlongeron 7 left side to longeron 7 right side, and lower fuselage longeron t7 to longeron20 on fuselage left and right srdes, be accomplished at intervals not to exceed 1500landings.

It is recommended that repetitive visual inspection for cracks of bottom areas fromlongeron 20 left side to longemn 20 right side, be accomplished at intervals not toexceed 3500 landings.

It is recommended that cracked tee section be replaced prior to further pressurizedfl ight

E. Anpmval:

The resultant modification described m paragraph l.C has been shown to comply ~7ththe applicable Federal Avlanon Regulations and is approved by the Manager. LosAngeles Aircraft Certification Office, FAA Northwest Mountain Region, on February13, 1990 and is approved as an alternate means of compliance with paragraphs A andB of Airworthiness Directive 89- 16- 12.

F. Man ower:

NOTE: Man-hours are estimated based on work to be performed by skilled personnelon aircraft’unit wluch has ben p laced in a marntenance s ta tus . The manhour/elapsed tune esnmates do not include:

1. Preparation for the modificat ion: E x a m p l e s ; defuehng, pun,placing work stands, openmg standard access doors, obtainmg tools,and jacking when not essential to the modification

2. Nonproductive elapsed time: Examples; sealant or adhesive cure time,cleamng, pamt drying nme. lunch and/or rest penods. and quali tyassurance inspecnons.

hlarch 2880 Bulletin .W-.W

Page 5

AC 43-204Appendix E

a/14/3-1

ScLllPLE VISU.AL INSPECTION PROCEDURE

3. Admmistrauve functrons: E x a m p l e s : planrung. ewneenng liaison.parts reqmsluon. shift change coordrnataon. and report wntmg.

Operations should tie the above into conslderahon when scheduling tiusmodificaaon.

Inspecnon fmm Aft Side of Bulkhead

Optical ly aided visual inspection from the aft side of the fuselage aft pressurebulkhead may be accomplished in appru.ximately 22.0 man-hours or 11.0 elapsed hoursper an-craft.

Man-hours do not include rime for fabricataon of flexible borescope gurde tube.

G. Material - Cost and AvaAabilitr:

rl) h-craft.

Parts and matenais requu-ed to accomplish this modificanon are listed inparagraph 3.h and are to be procured as rndxated. Parts bearing DouglasAircraft Company part numbers are propnetary parts and must be procuredunder the spare parts article of the purchase agreement. unless methods ofmanufacture are shown.

Cost and availability of parts ~FZ to be negotiated between the operator andDouglas Au-craft Company. Reference this Service Bulletin number and du-ectulquines to:

Douglas Aircraft CompanyP.O. Box 1771Long Beach. Califorma 90801Attn: Parts Sales - Commercial 73-44

(DC-9 Ser.xe Bulletm A53-2321

(21 Spares:

Sot applicable.

H. Toolmg Price aud Avallabilitv

Inspecnon from Aft Side of Bulkhead

11, Special test rqulpment IS required to accomphsh wsual mspectlon outlined mthis Service Uulletm. Special test equlpmcnt 1s to he procured from operator’sbtock. or other sources.

BulletIn ‘XX-XXX March 28/90

Page 6


SXvlPLE VISUAL INSPECTION PROCEDURE

I21 Rrocurement and avrnlability of Specml Test Equipment should be negotiatedbetween the operator and the Douglas Aircraft Company. Spe+ this ServiceBulletin number and direct mquiries to:

Douglas Aircraft Company910 East 236th StreetCarson, California 92805Attn: Manager. Recovery & lModificatlon

Services t RAMS)(DC-9 Service Bulletin A53-232)

I. 4’eight and Balance:

Weight change at appropriate fuselage statrons by incorporation of any part of thisSetice Bulletin is contingent upon the modification of each particular aircraft.Weight data is to be computed by the operator by weighing parts installed and partsremoved during modification. Necessary revisions should be made to the appropriateweight and balance report

J. Reference:

11) Federal Aviation Admmistration Airworthiness Directnve No. 89-16-12:Amendment 39-6287, effechve September 7. 1989.

12) Data used in preparanon of this Alert Servxe Bulletin:

Data Identicataon

DMS 2082JO60 157JO60 157M&l Chapters 6, 20.21, 25, 26. 36,49. 52. and 53NDT Chapter l-3SRM Chapters 51 and 53SR0953000 1SR0953000 1SRO9530048SR09530056SR09530056SR0953008359101305930760

Change

AB

CD

NewCD

NewDYAM

True of Data

Douglas LMaterial SpecficatlonService Rework ShoringAdvance E.O.Maintenance Manual

Nondesmctive Testing ManualStructural Reparr ManualServxe Rework DrawmgAdvance E.O.Service Rework DraHrlngService Rework DraurlngAdvance E.O.Service Rework DrawingDrawmgDrawing

131 Data supphed in support of this Alert Servtce Bulletin:

Data Identtficahon Chance Tvpe of Data

.I060 157 A Ser.~ce Rework Shorm,:

.jO60 157 13 (Idvanctl E.0

P a g e 7

AC 43-204Appendix E

8/ 14/3'1

SR0953000 1 c Semce Kework ShonngSR0953000 1 il :Idv~~ncc E.O.SR095300x! St?W Ser-ace Rework DrawtnqSR09530056 c Servxe Rework DrawingSR09530056 D Advance E.O.SR09530083 SPW Service Rework Drauang

K. Publications AfTected:

The modificataon outlined m this Service Bulletin af%cts the DAC DC-9 Weight andBalance Charts.

2. Accomplishment Instnrc~ons

WARNING. TO AVOID INJURY TO MAINTENAN’CE PERSONNEL OR DAMAGE TOEQUIPMENT. MAKE CERTAIN ADEQUATE PRECAUTIONS ARE TAKENWHILE PERFORMING ANY WORK IF ELECTRICAL POWER IS APPLIEDTO THE AIRCRAFT.

CAUTIONS ELECTRIC:ULY GROI-ND TIIE AIRCRrm.

GENERAL NOTES:

1. Refer to sections of the Maintenance Manual (MM). Structural Repalr \lanual[SRM).

Refer to the following manual chrjptrrs for applicable operations

M a n u a l Chap te r Operation

AM.34 20-30-O Sealant ApphcabonSRM 51-10-4 Drilling And Counters~rikqSRM 51-30-l Installing Bolts, Screws, and \vashersSRM 51-30-2 Removing And Installing RiversSRM 5 l-30-3 Removing And Installing LockboltsSRM 51-30-5 Removing And Installing Pins

For approved fastener and process material substituuons. see DC-9 SRMchapter 51-60-0, p<mgnph entitled “Interchangeability of Fasteners” and“Interchangeability of Materials.”

4 If the length of the fasteners specified tn thus Servtce Bullem do not meetacceptablr mstallation standards. fastenem of the sxnc type. or approvedsubsutuuons. one mcrcmeut longer or shorter in length may be used

A rombtneti t o t a l o f t w o 1 maxunurnt L16-tnrh t h i c k w a s h e r s o r f o u r(max~murn 1 L’32-mcb thick washers or any combinatton thereof not exceeding1/8-m-h tot.11 stackup tluckness of the washer types called from m tlus Service

Hullettn X X - X X X March 28l90

?age 8

8/14/97 AC 43-204A p p e n d i x E


Bulletin may be used under fastener head or nut to counteract accumulabonof tilerances.

5. If substitutions are used other than those in Douglas approved publicaaons,operator must obtain FAA approval from local authorized agency.

Insnecaon from Aft Side of Bulkhead

A. Operator’s Option . Access doors may be installed In skin on bottom of fuselagefonva.rd of auxiliary power unit (APU) door per service rework drawmg SR09530048to facilitate inspecaon

B. Operator’s Option - Fabricate guide tube it0 be used with fletiscopel from !letible orthin WELU tubing to fit outside diameter of fleldscope as shown on Figure 1.

C. Cain access to inspection areas on af? side of bulkhead by opening or removing andretaining the following access doors/panels as applicable to accomplish visualinspection;

Access No.

5806A

Access Area

Au?uliary E.tit Door,Non-Venual Bulkhead

MM Chapter

6-12-O

5901A

5902A

5903A

5904X

5910A

5911A

5912A

Thrust Reverser ControlValve (Left Side)

6-11-4

Thrust Reverser ContmlValve (Right Side)

6-11-4

A.PU Service (Left Side) 6-11-4

APU SeMce 1 Right Side)

Ventral Stair Ceiling

Ventral Stair (Right Side)

6- 1

6-l

6- 1

l-4

2-o

2-o

Ventral Stair ( Left Side) 6- 12.0

NOTE: The following paragraphs 2.D through 2.H may be accomplished at operator’soption and are applicable to visual inspection requirements.

D. Remove and retain APU and attaching parts. (See MM chapter 49-10-O. paragraphentitled “RemovalAnstalla~on Power Plant.“)

E. Remove and retain APU compartment enclosure and attachmg parts. (See ,MM.chap te r 53-20-5. pa rag raph entltled “Removal/lnstallaaon .kPU CompartmentEnclosure.“)

hlarch 25/X1

Page 9

AC 43-204Appendix E

8/14/97

E

F.

G.

H.

I.

J .

Ii

SAMPLE VISUM, IIGSPECTION PROCEDURE

Remove and retam lower firex bottle and attack parts. (See 11M chapter 26-20-l.paragraph entitled “RemovaUInstalla~on Fire Extingnlshing Contzuners.“)

Remove and retain right pneumatic crossfeed valve pushrod and attach.mg parts. (SeeMM chapter 36-10-3, paragraph entitled “Removal/Installation Pneumanc CrossfeedValve.“)

Remove and retain two upper conditioned air duct assemblies, check valves, andattaching parts aft of pressure bulkhead center ceiling. (See IMM chapter 21-20-2,paragraph entitled “Removal/Installation Conditioned and Cold Air Check Valve.“)

Roll back or remove and retain insulation blankets from aft side of aft pressurebulkhead. (See MM chapter 25-22-O. paragraph enti t led “Removal/Instal lat ionInsulation Blankets.“)

Perform optically aided visual inspection/repair of the aft pressure bulkhead web tofuselage skin attach tee sections from the af? side of the bulkhead as follows:

(1)

(2)

i3)

14)

15)

Inspect the upstanding leg of 5910130 ventral bulkhead tee sections from aftside of bulkhead around the periphery of the bulkhead as shown on Figure 3and accomplish the following:

Condition 1 (No Crack)

Perform repentive visual inspections from af? side of bulkhead at mtervalsspecrfied in Comphance paragraph.

Condition 2 (Crack)

Replace cracked tee section with new like or unproved part per Figure 4 (SeeTable I for configuration) prior to further pressurized flight. Perform repetltlvevisual f r o m a!? side o f b u l k h e a d a t I n t e r v a l s specfied i n C o m p l i a n c ep=agraph

If any tee secnon is to be replaced. remove and retam engines 1 and 2. (SeeMM chapter 71-00-0, paragraph enDtIed “Removal/lnstaUation Power Plant.“)

Shore aucraft as shown on Figure 5.

Record and report all results, both negative and posinve of inspection to DAC. Includefuselage number, factor serial number, crack location. crack length, flight-hours, andaccumulated landings of aircraft Forward to:

Douglas Aircraft CompanyP.O. Box 1771Long Beach. Califorma 90801Attn. Manager. Customer Serx-~e 73-30

I DC-9 Alert Service Bulletin AS3-232)

Bulletin XX-XXX March 2&90

‘age 10


L.

hi.

N.

0.

P.

Q.

R.

S.

T.

LT.

SAMPLE VTSUAL INSPECTION PROCEDURE

Apply PR-1422 B-2 sealant around entire periphery of the bulkhead tee sections. asapplicable.

Reinstall retained insulaaon blankets on aft side of aft pressure bulkhead. (See &ixchapter 25-22-0, paragraph entitled “Removal/Installation Insulation Blankets.“)

Reinstall nght pneumatic crossfeed valve pushrod and attaching parts as applicable.(See MM chapter 36-10-3, paragraph entitled “Removal/Installation PneumaacCrossfeed Valve.“)

Reinstall two upper conditioned air duct assemblies, check valves, and attaching partsas applicable. (See MM chapter 21-20-2. paragraph entitled “Removal/InstallationConditioned and Cold Air Check .Valve.“)

Reinstall lower firex bottle and attaching parts as applicable. (See IMM chapter 26-20-1, paragraph entitled “Removtinstallation Fire Extinguishing Containers.“)

Reinstall APU compartment enclosure. as applicable. (See IMM chapter 53-20-5.paragraph enutled “Removal/Installation APU Compartment Enclosure.“~

Reinstall API-7 and attaching parts as applicable. (See 1fM chapter 49-10-O. paragraphentitled “RemovaYTnstition Power Plant.“)

Remstall engrnes 1 and 2 as applicable. (See MM chapter 71-00-O. paragraph enatled“RemovalAnstallation Power Plant.“)

Remove shoring as shown on Figure 5 as applicable.

Close/retnstaU access doorvpanels as outlined under Option I paragraph 2.C.

March 'L&90 Bulletin XX-XXX

Page 11

APPROX 3 FEET

APPAOX2-3 INCHES-P

flEXIBILE OR THIN U9E 1.0.YALL TUBING c FIT 0. 0.

CF FLEx~SCOPEDETAIL FLEXISCOPE GUIDE 1UBE

HAKf FROM COnnERClAL FLEXIBLE OR THINYALL TUBIHC 3/B OR l/Z-INCH DIAMETER

SIA X--IO.000 STA X - 4 0 . 0 0 0

- - - - + - - --

I

L Iis K INTERCDSIAL

P,2 I3-

VIEW LOOKING FORWARD RIGHT SIDEAT FRAHE IHSTALLATlON AFT OFPRESSURE BULKHEAD

lLLUSTRAllOk~OF=CU1OE TUBE USE

STA Z--40.000

8/14/9’7 A C 4 3 - 2 0 4A p p e n d i x E

SAMPLE VTSUAL INSPECTION PROCEDURE

GENEhU NOTES:

1. PERFORM INSPECTION PROCEDURE A. SEQUENCES 1 THROUGH 3 BEFORECLEANING THE TEE Ah’D AFTER CLEANING THE TEE AS NOTED.

7-. PROCEDURE A - DESCRIBES A.. OF’TICALLY AlDED VISUAL INSPECTION OF DC-9 ru;TPRESSURE BULKHEAD WEB TO FUSELAGE SKN A’ITACH TEE SECTIONS TO DETECTFATIGUE CRACKS IN THE U-PSTANDNG LEG OF TEE SECTIONS.

3. INSPECTION OF THE BULKHEAD TEE FOR CRACKS BY PROCEDURE A IS MADEFROM THE AFI’ SIDE OF THE AFT PRESSURE BULKHEAD.

4. INSPECTION BY PROCEDURE A IS DIVIDED INTO THREE SEQUENCES BASED ONACCESS LOCATION.

5. SIGNS OF NICOTINE STAINS MAY INDICATE CRACKS.

6. THE FOLLOWING EQUIPMENT OR EQUIVALENT IS REQUIRED:

SEE PARAGRAPH 3.C FOR TEST EQUIPMENT SUPPLIERS

VISUAL EQUIPMENT

a.

b.

FLASHLIGHT.

INSPECTION MIRROR WITH ADJUSTABLE VIEWING ANGLE.

ENDOSCOPE EQUIPMENT:

C. ONE ‘70 OR 90 DEGREE ENDOSCOPE OF ANY DIAMETER WITH If&INCH(457.2 MM)) MINIMUM LENGTH AND LIGHT SOURCE SUCH AS:

(1) ENDOSCOPE MODEL 10320D. 70 DEGREE t FOREOBLIQUE 1ANGLE. 19-INCH (482.6 MM) LONG, 0.217-ISCH DIkMETER.

(2) FIBER OPTIC LIGHT BUNDLE MODEL 495NL.

(3) ENDOSCOPE LIGHT SOURCE NUMBER 00482 ( 110 OR 220 VOLT)OR NUMBER E0590 ( 110 VOLT ONLY ).

14) SYLVANLA PROJECTOR LAMP (150 WATT. 120 VOLT).

AFT PRESSURE BULKHEAD TEE INSPECTION

FIGL-RE 3 (SHEET 1 OF 1~ I

.&larch 2990

P a g e 1 3

AC 43-204A p p e n d i x E

g/14/97

SAAIPLE i’ISU.4L IIUSPECTIOK PROCEDURE

FLESIBLE BORESCOPE:

d. ONE FORli'ARD \-IE\VISG ENDOSCOPE OF .%.\--I. DLUiETER \VITH 30INCH .MINI,MIJ-M LENGTH SUCH AS:

11) OLYMPUS .MODEL lF8D3, 29.8.INCH (757 ,MM) LONG, 0.315.INCHDIAMETER.

(2) COLD LIGHT SUPPLY NUMBER 1LK-4 (100 TO 230 VOLT).

INSPECTION PROCEDURE

.A. VISUAL INSPECTION PROCEDURE A,

SEQUENCE 1:

i 1, PERFORM MIRROIWXASHLIGHT OR ENDOSCOPE INSPECTION OFUPPER FUSELAGE TEE SECTIONS FROM LOSGEROS L; LEFT SIDE TOLOXGERON L7 RIGHT SIDE. LOWER FUSELAGE LOSGERON L17 LEFTSIDE TO LONGERON L20 LEFT SIDE. .-LVD LONGERON L17 RIGHT TOLONGERON L19 RIGHT SIDE.

12) PERFORM ENDOSCOPE OR FLE‘XIBLE BORESCOPE INSPECTION OFLOWER FUSELAGE TEE SECTIONS FROM LONGERON L19 RIGHT SIDETO LONGERON L20 RIGHT SIDE.

SEQL-ESCE 2:

(11 PERFORM MIRROWFLXSHLIGHT OR ENDOSCOPE INSPECTION OFLOWER FUSELAGE TEE SECTION THROUGH THRUST REVERSERLOCKOUTACCESSOPENING 5902AFROMLONGERONL20RIGHTSIDETO LONGERON L24 RIGHT SIDE.

NOTE: SEQUENCE 2 AND 3 M A Y B E A C C O M P L I S H E D USISGINSPECTION MIRROR tWD FLASHLIGHT IF SLFFICIENTACCESS IS AVAILABLE.

AFT PRESSURE BULKHEAD TEE - INSPECTION

FIGURE 3 (SHEET 2 OF 1~ 1

Bulletin XX-XXX March 28/90

1? a g e 1 4

8/14/97 AC 43-204A p p e n d i x E


SEQUENCE 3:

(1) PERFORid VISUAL LiiSPE~TION OF LOWER FUSELAGE TEE SECTIONSWITH FLidHLIGHT FROM LONGERON L23 LEFT SIDE TO LOSGERONL24 RIGHT SIDE.

REMOVE SEALANT FROM INSPECTION AREA OF TEE SECTIONS THAT ;MAyHINDER INSPECTION. CLEAY DIRT, GREASE. AND ALL FOREIGN MiiTERuFROM LNSPECTION AREA OF TEE SECTIONS USING LLNT-FREE WIPER AND1.1.1 TRICHLOROETHANE SOLVENT OR EQUTVALENT. PERFORM INSPECTIONSEQUENCES 1 THROUGH 3 AFTER CLEANING T= TEE SECTIONS.

AFT PRESSURE BULKHEAD TEE - INSPECTION

FIGLVRE 3 (SHEET 3 OF 141

Bulletin XX-XXX

P a g e 1 5

AC 4 3 - 2 0 4Appendix E

8/14/97


LlU \

‘.., ~z=63~5jslo130-54

fi

,Lll ORL12 5910130-392H- Zm48 TEE

ILL UPPER^-. a.*

\ L 17 - \\'\

j” v? .i’ . :v;/\, ,, 5910130-56

591OiJO-387 LL =TEE 5 *

2 = STATION

FRP = FUSELAGE REFERENCE PLANELOFT LINEPROOUCTION SPLICE

VlEY LOOKING FORWARD

DC-9 VENTRAL AFT PRESSURE BULKHEAD SCHEMATIC OIAGRAn SHOVING TEE LOCATIONS

.VTPRESSL-RE BCLKHEcU)TEE - INSPECTION

FIGL-RE 3 (SHEET 4 OF 1.t)

Bulletin XX-IiXi March 2EY90

Page 16

8/14/97AC 4 3 - 2 0 4

Appendix E


CftACK

INSPECTION

FWD

IN80

70’ OR 90. ENDOSCOPE

DETAIL A - ENDOSCOPE VISUAL INSPECTION

5910130BULKHEADTEE

Il6PECTION

D E T A I L B - HlRROR FLASHLIGHT VISUAL INSPECTION

SEQUENCE 1 VISUAL AND ENOSCOPE INSPECTION OF BULKHEAD TEE

AFT PRESSIJ?IE BULKHEAD TEE INSPECTION

FIGI:RE 3 (SHEET 5 OF 1.11

Bulletin X X - X X X

P a g e 1 7

AC 43-204A p p e n d i x E

8/14/97

SAMPLE \?SUAL INSPECTIOK PROCEDURE

SECTION A-A

BulletIn >c7(-XXX

LOOKING FORYARO

TEE

SPLICE

WEB

S E C T I O N B - B‘yi

DC-9 VENTRAL AFT PRESSUREBULKHEAD. TEE CAP CRACKS

AFT PRESSURE BULKHEAD TEE. ISSPECTION

FICL-RE 3 (SHEET 6 OF 1.11

O U T B D*

hlarch 2&‘90

age 18

a/14/97 fiC43-204Appendix E

SAIKPLE VISUAL INSPECTION PROCEDURE

C. The basis for the follow-inn tooline data is per operator

N O T E : C A G E mdlcates Commercml a n d G o v e r n m e n t Enat); c o d e f o r.Manufacmre~Dtstnbutors.

(li Optlon : . Test equipment to be procured from operator’s stock or sourcesmdicated.

Test Equipment '& CAGE

Endoscope 70 Degree(Fore oblique) Angle19-Inch (482.6 MM) Long0.217-LnchDiameter

orEquivalent

Model103’20D

1 5434 1 E.xpanded Opacs.Incorporated301-c West Dyer Roadkhnta h. Califorma

92702.3427

NOTE: One 70 or 90 degree endoscope of any diameter wth la-inch (157.2 MM] muumumlength and matching light source may be used.

Fiber OptxLight Bundle

i&lode11 FBD3

1 5434 1 Expanded Optxs.Lncorporated301-C West Dyer RoadSanta Ana. Califorma

92702 -3427

andEndoscope Light Source110 or 220 Volt

No. 00482

NzrE0590

5434 1 Expanded Optics.Incorporated301-C West Dyer RoadSanta Ana. California

92702.342:

andSylvama Projector Lamp150 Watt 120 Volt

1 5434 1 Expanded Opncs.Incorporated301-C West Dyer RoadSanta Ana, Cahforma

92702.3427

NOTE Slmrlar or eqtuvalent endoscopes and tllummatorj may be obmned from the followmgsources.

hlarch 28/90

P a g e 1 9

AC: 43-204Appendix E

8/14/97

SAiVl’LE VISUAL INSPECTIOK PROCEDURE

Test Eaumment

Flexible Borescope29.8.Inch (757 MM) Long0.315.InchDiameter

Cold Light Supplyloo m 230 Volt

orEquivalent

C& C A G E S u p p l i e r

AIva IngemerosVelazquer 12 1Madrid 6, Spain

orAut~mahon InstrumentsService

47 Birch StreetBankston 2200, Australia

or3 C ElectronicsSede Commercial 20135M.&m0 Via Perugino 9, Italy

or50958 Richard Wolf

M e d i c a l I n s t r u m e n tcorporation7046 Lyndon AvenueRosemont. Il.Iinols

600183410or

Inspecnon Instruments NDTLimited

32 Duncan TerraceLondon N 188R, England

orKarl Storz KGD 7200 ‘I’uttlingenWest Germany

.ModellF8D3

1 32212 Olympus CorporationScientific Products Group4 Nevada DriveLake Success, New ‘fork

11040-1114

No. lLK-4 1 32212 Olympus CorporationSciennfic Products Group4 Nevada DriveLake Success. New York

11040-1114

Bulletln ‘XX-XXX March 28'90

Page 20

a/14/97

APPENDIX F. BOEING 747 SERVICE BULLETINSAMPLE INSPECTION PROCEDURE

AC 43-204Appendix F

Excerpts of Boeing Service Bulletin 747-53-2307, Dee 21/89.

Retyped with permission of Boeing Commercial Airplane Group.

Page 1

/1:43-204A p p e n d i x F

8/14/97

SAMPLE I’ISU.ti IXSPECTIOlG PROCEDURE

SUMMARYBOEING CC4B&f+ElM AIRPUNES POST CYFKE BOX 3707 SEATKE. WASHINGTON Q81?4-2207

BACKCROWD

This mspection wtll detect corrosion and fatigue cracks in upper body skin longitudinal iap jointscaused by.disbonding of the cold bond at the JOlnL Conhnued operation of an airplane that hascorrosion or fatigue cracking in lap points could lead to separation of the skin at the lap jointcausmg rapid decompression of the airplane.

Several operators have reported corrosion. and associated bulgmg of slun at upper body lap JOlntS

on axplanes with 26,733 tc 70.000 flight-houm. One operator reported cracking and corrosion ofthe lap joint at Stringer 12 from Station 1515 to 1735 and Stringer 4L at Statron 1710 on anau-plane with 35,134 flight-hours. One other operator reported corroslon and cracking at the lapjoint at Smnger 4R. Station 1500 on an airplane with 49,024 flight-hours. hother operatorreported a one-inch crack at Stringer 0. Station 738 suspected to have been caused by corrosionfi-om disbondmg at the cold-bonded lap jomt. There have been numerous addrtional instances ofcorrosion reported at the Smnger 23 lap joint

This bulletm supersedes that portion of Senxe Bulletin 747-53-2157 wmch addresses the upperbody slun Iongtudmal kxp ~omts.

Arplanes previously inspected per Service Bulletin 747-53-2157 requue additional inspection oflap joint areas as described herein.

.tiy lap joint areas repaired per Service bullehn 747-53-2157 do not requxe further rep= ormspecnon.

This bulletm does not supersede Service Bullets 747.53.,,3153 or Service Bulletin 747~53A2303wmch address the upper hodv sicln Ionmni&nal lap JOmb at Stringer 6 m Secnon 41.

Tms senlce bullcnn ts the subject of Federal Aviauon Admnustxauon (FAA, Notice of ProposedRulemting 83.NXl- 19.1-M) dated February 9, 1989.

ACTIOS

M’ithin 1.000 flight-cyc!es after n,ceipt of thus bullcun. conduct a detailed external v-~.uaImspecuon of the upper body lonqtuhd lap JOLOLS at Stringers 23 and above from Station 140 to2360 (except Stringer 7 fmm ~tauom 3.10 to 5201. \‘lsually inspect ah lap JOLLILS for evidence ofcorrosion or cnclunx. ELxicnce of corrosion includes rmssing or distressed fasteners. wb~te powderprotruding from the lap joint. or bulging or pillowing of the lap Jomt between fasteners. Repaxany cormslon beyond allowable llrmts or cracking. as specified herein. pnor to further flightRepeat these visual lnspecriot~ at mtervals not to exceed 1.000 flight-cycles for the lap points m

Secuons 4 1, 42. ,Ind 46 Repeat the visual inspecuons at 2.000 flight-cycle mtervals for the lapJoints tu Sectron 4-I

Dee 21189 747-53-2307

Page 2

g/14/97 AC 4 3 - 2 0 4Appendix F

L A P J O I N T( T Y P I C A L )

/ r\ S-6

4 2 & I

S E C T I O N S

LUSPECTMPJOLUTS FORCORRORSION.CR4CKSORPILLOWINGOFSKIN,ANDMISSINGORDISTRESSED FASTENERS

\

Page 3

BOEING SERVICE BULLETTN 747-53-2307

R I G H T S I D E S H O W NL E F T SIDE O P P O S I T E

Dee 2 1 ifi

SiA<4’ 1000

AC 43 -204Appendix F

R / 1 4 / 9 7

BOEIKG SERVICE BULLETIN 747-53-2307

In lieu of continued remspecuons. termmatxq acuon may he accomphshed. Terrmna~nq action ISaccomphshed when an uncorrodcd lap Joint area IS separated betwwn adjacent cu-cumferentlalsplices. adhesive removed, faymg surface sealant 1s applied, and Joint IS refastened per 747Structural Repar iManual SubJect 43-30-03. Termmating action in a corroded or cracked lap jointarea may be accomplished when the area 1s repau-ed per 747 Structural Repair Manual Subject 53-30-03.

EFFECTIVITY

747 Au-planes Line poslbon 001 through 200

Visual Inspection:Total Manhours . 152 per AirplaneElapsed Time - 38 Hours

MATERIAL ISFORMATION

None.

Dee ‘21189 747-53-2307

P a g e 4

g/14/97 AC 43-204Appendix F

BOEING SERVICE BULLETIN 747-53-2307

SERVICE BULLETIN

ATA SYSXEM: 53105331

NUMBER: 767-53-2307 DATE: December 21, 1989

SUBJECT: FUSELAGE - SKIN - UPPER BODY SKIN LONGITUDINAL W JOINT(STRINGERS 23 AND ABOVE) INSPECTION AND REPAIR

1. PLANNING INFORMATION

A. Effectivity

1. Airplanes Affected

See Setice Bulletin Index Part 3 for cmss reference of Vanable Number toAirplane Serial Number.

Tbs change 1s applicable only to arplanes listed below

CODE VARLABLE NCXBER

ACN RA743

A!=A RK251-FM259

AKN RA722-FL4724

tlRL MO3

BAEI W17FLA702

CAL R451-R4552

CLY IL4023 mo25

Dee 21:69

RA501-RA502

RA301-RA308 lu310 Ru12

747-53-2307

Page 5

AC 43-204A p p e n d i x F

8/14/97

CODE

EL4

EVR

FTL

VARIABLE NUMBER ICONTINVED)

IBEIRN

JAL

KLM

MKR

NAS

1NWA

OR1

PAA

RB043

R4022 Ml13

Rio29 RAo33 RA632RA741 RA916 RB041

RA112 EU161-RA163

RA532-FU534 R4537-RA540

RA245 lu201

RA677

FU369-RA373 FtA601-lU602

PEX

QiLV

SAA

SAB

TWO

TWA

R4781-RA782

RAoo3-RAoo4

RA026RA634-RA635

RA585FulOl-FM103

R4521 -IV&27

IX?16

RA671-RA675

RA701

RA908

RA351-RA360

RAo20

RAoo2RAO27-RAO28RA631

R4559

RA909

RB071-RB075

RBlOl-RB102

IWO24

RA104-Ml10FM311

RA406-RA4 14

RA90 1 M902

R4560

RA742

RAOo5-RAoo7 RAoo9 RAOlZ-RAo19RAO30-R4032 RA034R.4633 RA910 Fug14

RA561 RB003-RB005

RBOOl-RB002

RA201 R4761 RB042

RA114-ml15 FM164 IL4309RA581-R4582 RA651-RA652 RDOOl-RD002

RA903-FLA907

RA911-RX313 &\915

RAY62 RB044

Dee 21189 747-53-2307


I?age 6

AC43-204A p p e n d i x F

BOEING SERVICE BULLETIK 747-53-2307

CODE VARIABLE NUMBER (CONTINUED)

LISTING BY VMIABLE NUMBER

RAOO2.RA034 Rr\lOl-R4115 f&161-ml64 RA201-RA203 ~16-Rx21’iRA245-FL&,?46 R4251-R4259 RA301-Ew312 R4351-RA360 RA369-RA373RA401-RA414 RA501-RA502 FW521-RA527 RA532-RA540 U551-RA552FiA559-FtA561 RA581-R4582 -85 RA601-RA602 RA631-RA635RA651-FtA652 RA671-FM677 RA701-R4702 RA721-RA724 RA741-RA743RA761-RA762 Rx781-RA782 Iu901-U916 RBOOl-RB005 RB041-RB044RB071.RB075 RBlOl-RBl02 RDOOl-RD002 RR201

2. Spares mected

None

B. Reason

This tnspection will detect corrosion or cracking in upper body skin longitudinal lapjoints caused by disbanding of the cold bond at the lap jotnt. Continued operationof an airplane that has corrosion or cracking in lap joints could lead to separationof the skin at the lap joint causing rapid decompressron of the airplane.

Several operators have reported corrosion and assocrated bulging of skin at upperbody lap joints on airplanes with 26,733 to 70,000 flight-hours.

One operator reported corrosibn of one to three lap joint rivets and bulging of theskin at Stringer 12 near Station 1694 on an airplane with 34,827 flight-hours. Thisoperator also reported cracked and corroded fuselage skin mth separation at thelap joint at Stringer 12 L and R at six locations each side from Station 1515 to 1735and Stringer 4L at Station 1710 on the same airplane with 35.134 flight-hours.

Another operator reported a one-mch skin crack emanating from the iap joint atStringer 0 near Stanon 738 on an airplane with 49.800 flight-hours which wassuspected to have been caused by corrosion from disbanding at the cold-bonded lapjoint (Ref. SIIA 747-71). This operator also reported two airplanes with skincorrosion of lap joint at Stringer 4L. On one airplane. with 35,985 flight-hours, thiscorrosion was found at four locations between Stations 1482 and 1676. On theother airplane, corrosion was found near Stations 1510 and 1615 on an airplanewith 36,461 flight-hours.

Also an operator has reported skin corrosion m the lap joint at Stringer 23R nearStation 1400 on an airplane with 26,733 flight-hours and skin corrosion withbulging skin involving the lap joint at Stringer 23L between Station 1720 and 1820on another airplane.

There have been numerous additional instances of cormsron reported at theStringer 23 lap Jomt.

Dee 21/89 747-53-2307

P a g e 7

AC43-204A p p e n d i x F

a/14/97


13. (Continued)

Tms bullets supersedes that pomon of Serv-tce Bulletin 747-53-2153 wmchaddresses the upper body skin longitudinal lap joints.

Airplanes previously Inspected per Service Bulletin 747-53-2157 require additionalinspection of lap joint areas as described herein.

Any lap joint areas repaired per Service Bulletin 747-53-2157 do not require furtherrepair or inspection.

This bulletin does not supersede Service Bulletin 747-53-2253 or Service Bulletin747-53A2303 which address the upper body skin longitudinal lap joints at Stringer6 in Section 41.

This service bulletin is the subject of Federal -4viation Administration [FAA) Nouceof Proposed Rulemakmg 88.SM-1954-AD dated February 9, 1989.

c . Description

Within 1,000 flight-cycles afier receipt of this bulletin conduct a detailed externalvisual mspection of the upper body longitudinal lap joints at Stringers 23 andabove from Station 340 to 520). Visually inspect all lap joints for evidence ofcormsron or crackmg. Evidence of corrosion includes missing or disnessedfasteners, white powder promding from the lap joint, or bulging or pillowmg of thelap joint between fasteners. Repau any corrosion beyond allowable huts orcrackmg, as specified herem. prior to further flight. Repeat these visual inspectionsat intervals not to exceed 1.000 flight-cycles for the lap joints in Sections 41(Stahon 140-520), 42 (Station 520-1000). and 46 (Station 1480-23601. Repeat thevisual mspections at 2,000 flightcycle intervals for the lap points m Secuon 44c Stanon lOOO- 14801.

In lieu of contmued reinspecnons, temunating action may be accompbsbed.Termmatlng acuon 1s accomplished when an uncorroded lap jomt area 1s separatedbetween adjacent circumferential splices, adhesive removed, fay-mg surface sealantis applied, and joint is refastened per 747 Stnrctural Repair Slanual Subject 53-30-03. Tenmnatlng actron in a corroded or cracked lap joint area may be accomplishedwhen the area IS repaupd per 747 S~~ctural Repair .Manua.l Subject 53-30-03.

It IS recommended that this servLce bulletin be accomplished concurrently withserme bulleuns 747.53A2265 and 747-53A2279 due to common access.

This service bulleton is the subject of Federal Aviation Administraaon (FM) Noticeof Proposed Rule .Making, FAA Docket Number 88-NM-194-AD. issued February 9,1989.

D. Approval

This service butlean has been renewed by the Federal Aviauoo AdmimsrmaonI FA.+II and the repass and modificanons herein comply with the applicable FederalAvmuon Regulations I FAR’s) and are FAA approved.

Dee 21189 747-53-2307

?age 8

g/14/97 AC 43-204Appendix F

BOElNG SERVICE BULLETIN 747-53-2307

D. (Continued)

The deferral of repair described in Accomplishment Instructions, has FAA approvalconungent on accomplishment of the mspecnons at the intervals spectfied m theAccomplishment Instructions.

E. Manpower

The following breakdown of manpower requirements is suggested as a guide toassist operators in planning and accomplishing this modification This estimate 1sfor direct labor performed by an e.xperienced crew. It does not include setup,planning, familiarization. cure time, part fabrication, tool acqtusition. or lost tame.Factor this estimate as necessary based on your own expellence.

(a

ElapsedTime

Operation Crew size Man-Hours tHouis

Visual Inspection 4 152 38of Lap Joints

TOTALPERAIRPLALVE (a) 152 38

Crew size, man-hour and elapsed time shown does not include time for lapjoint repair or access to accomplish such repair since it is dependent on theextent of repairs required. It is assumed that operators will not performterminating action on all lap joint areas at one time. Therefore, crew size,man-hours and elapsed time should be based on operator’s experience andon the length and location of the lap joint for which terminating action isaccomplished. Accomplishment of terminating action is estimated to be 96man-hours for each 200-inch length of uncmcked and uncorroded lap joint

F. Material - Price and Availability

None

G. Tooling - Price and Availability

None

H. Weight and Balance

No change

Dee ‘L li89 74i-53-2307

Page 9

~~43-204Appendix F

8/14/97

BOEIKG SERVICE BULLETIN ‘747-53-2307

I. References

1. E?asnng Data:

a. 747 Maintenance .Manual Subjects25-11-01, 25-11-02. 25-11-03, 25-11-05. 25-14-01. 25-19-00, 25-21-01,25-21-02, 25-21-04. 25-21-12. 25-22-01, 25-22-03, 25-22-06, 25-23-01,25-23-04, 25-23-05, 25-24-00, 25-24-05, 25-24-11, 25-24-12, 25-24-19,25-25-01, 25-25-03, 25-25-04, 25-26-02, 25-26-03. 25-26-06, 25-27-00,25-28-01, 25-28-15, 25-28-23. 25-31-04. 25-40-01, 25-40-03, 25-59-01.25-68-02, 31-00-00, 34-11-00, 35-00-00, 35-21-00, 52-11-01, 52-13-01.52-51-01, 53-21-01, 53-21-02.

b. 747 Structural Repair Manual Subjects 51-10-01, 53-30-03

c.

d.

e.

747 Non-Destructive Test Manual D6-7 170

747 Structural Item Interim Advisory 747.71

Boeing SeMce Bulletins 747-53-2157, “Body Longitudinal Skin LapJoints. Tear Strap’Skin Lap Splices, Window Forgings, Skin PanelDoublers, And Selected Skin Panel Corrosion Inspection”; 747-53.2253, “Fuselage - Nose Section - Station 340 to 400 Stringer 6 SkinInspection and Modification”; 747-53A2265. “Fuselage - Nose Section41 . Body Frame Structure Inspections and Crack Repairs”; 747-53A2279, “Fuselage - Skin - Upper Body Skin Bonded Tear StrapLaspecnon and Modification”; 747-53A2303. “Fuselage - h’ose Section-Stabon 400 to 520 Stringer 6 Skin Splice Inspection Repair andhlodificatlon”

f. FAA Notice of Proposed Rule Making, FAA Docket Number 88.NM-194-AD. issued February 9, 1989

J.

2. Data supplied in support of this service bulletin:

None

Publications Affected

Publication Chapter-Section

747 Corrosion Prevenaon Manual . . . . . . . . . . . 53-30-47

Dee 21189 747-53-2307

Page 10

8/14/97 AC43-204Appendix F


II. MATERIAL INFORMATION

A. Parts Required Per Airplane

None

B. Parts Required to Modify Spares

None

C. Special Tools and Equipment Required

No special tools or equipment are required to accomplish this bulletinMaintenance and overhaul tools may be required per any manuals that are listed inParagraph 1.1.. References. of this bulled Operators should review their toolinventory to ensure tool availability.

D. Existing Parts Accountability

None

Dee 21/89 i47-53-2307

Page 11

AC 43-204Appendix F

a/14/97

BOEINGSERVICE BULLETIK 747-53-2307

III. .~CCO~‘VIPLISHR~ENT INSTRUCTIONS

NOTES: 1. The following paragraphs outline the general accomplishmentinsuuctions. The suggested sequence of operations and detzuledaccomplishment instrucaons are indicated by circle notes on thefigUl-f?S.

0&. Observe all warning and caution notes in the referenced manual

sections.

3. Figure 1 contains the Logic Diagram presentations of the followmggeneral accomplishment insQucti0n.s.

A. For all lap joints affected by this bulletin as identified by Figure 2, performinspection of the lap splices using the method outlined in the logic diagrams ofFigure 1.

Method I

Within 1.000 flight-cycles after receipt of this bullean, perform a detailed externalvisual inspecaon of the affected lap splices per Figure 2 circle notes 1 and 3.Repair any corrosion beyond lirmts or cracking as specified in Figure 2 circle note 3.Repeat the detailed external visual inspection at intervals not to exceed 1,000Right-cycles for the affected lap splices m Section 41, 42, and 46. Repeat thedetailed external visual inspection at intervals not to exceed 2.000 flight-cycles inSecaon 44.

B. In lieu of conunued remspections, termrnatlng action may be accomplished.Terrmnaung acaou is accomplished when an uncorroded lap joint area is separatedbetween adjacent cucnmferentlal splices, adhesive removed, faylng surface sealantis applied, and jomt IS refastened per 747 Structural Repair Manual Subject 53.30-03 Figure 9 or 10. Terminating actton in a corroded or cracked lap joint area maybe accomphshed when the area is repaired per 747 Stn~ctuml Reparr ManualSubject 53-30-03. Internal lap joint access to accomplish terminating action can bemade per Figures 3 through 5.

SOTES. 1. When accomplishing termmaang action either with au-planein a specific jacked position or without jacking the airplane,contact Boeing for allowable length of lap joint which may bereworked j specify detAs of an-plane configuration includingweight and CC. jaclung configuration, and any other workbeing performed concurrently on the au-plane).

2. When accomplishing terminaang action on a specitic lapjoint length, contact Bcemg for jacking requirements (specifylap joint being reworked. details of an-plane configunuonmcludmg weight and CC. and any other work beingperformed concurrently on the an-plane~.

Dee 21189 747-53-2307

1?age 12

8/14/97 AC 43-204Appendix F


3. When refastening lap ~oiot per Structu~~~~ Repair ?AanualSubject 53.30-03 Figure 9 or 10, perform open hole HFECmspecnon per 747 Non-Destmctive Test Manual D6-7170,Part 6. 53-30-00. Figure 1, 3 or 4 to emure the lap joint 1scrack free pnor to resizing hole for installation overslzeprotruding head fasteners.

C. Restore airplane to normal c~nfigu~ti~n

Dee 21/&l 747--53-2307

Page 13

A’: 43-204Appendix F

R/14/37

BOEIKG SERVICE BULLETIN 747-5%Z307

Figure 1.

Figure 2.

Figure 3.

Figure 4.

Figure 5.

Illustranon Table of Contents

Title

E.xtemal Lap Jo in t In spec t ion Log ic Diag ram

E x t e r n a l L a p J o i n t Cormsion I n s p e c t i o n a n d Rep=

Flight Deck Lap Joint Internal Access . .

Upper Deck Lap Joint Internal Access .

Main Deck Lap Joint Internal Access . . . . . . . .

Page

12

16

26

30

32

Dee 21189

3ge 14

8/14/97

BOEING SERVICE BULLETIPi 747-33-2307

Inspection Method I

Withrn 1,650 Flight-CyclesAfter Receipt of thts Bullettn

Perform the Followtng 1D

Conduct a Detarled External VisualInspectron to Determine it Corrosionor Cracking Exisls at Cold-Bonded

LonoRudinal 8odv Skin Lap Joints at S-234 - - - - - - - -“-‘,

aid Above From Statton 140 to 2360(Fief Fig. 2) f$

Areas of Cracks

Conduct TerminatingAction on Affected

ICracks

L

r-Conduct Termrnatrng Actron on

Corroded Lap Jornt BetweenCrrcumrerentral Solaces Wrthrn

30 Months 3D

1 I 1Conduct Terminahng Actionon Pemarnder ol Lap Jornt

Wrthrn 15 Monlhs 3D I IJ

I 1I

r 1 II Repeat Inspectron of All Nontermrnated Lap Jornts 1 I

in Sections 41, 42. 44 and 46 at 1,000 Flrght Cycle Intervals k---------

FIGL-RE 1. EXTERSAL LAPJOIST ISSPECTIOS LOGIC DLjCR-L\I

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AC 43-204Appendix F

8/14/9-l

BOEIKG SER\TCE BULLETW 747-53-2307

DISl-lING O F F A S T E N E R kZ:AO

C R A C K S A TFASTENER SHANK

E X C E S S I V ECOUNTERSUNK DEPTH

2 . Heasuring o f p i l l o w i n g is a c c o m p l i s h e d b y u s i n g a s u i t a b l es t r a i g h t e d g e a n d t h i c k n e s s g a g e . Minimum length o f s tra ighte d g e should be 4 .50 inches . Se t be l ow :

S T R A I G H T E D G E4 . 5 0 MIN O U T E R S K I N

A T JOXNT

INBD I \u I N N E R S K I N A T J O I N T

S K I N P I L L O W I N GD I M E N S I O N

( P I L L O W I N G S H O W N E X A G G E R A T E D F O R C L A R I T Y )

FIGI;RE 1. EXTERVhL LkPJOIST ISSPECTIONL'CONTIh7JED)

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F'age 16

8/14/97 AC43-204Appendix F


Intenuonally Left Blank

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AC 43-204A p p e n d i x F

8/14/97

BOEING SERVICE BULLETII’; 747-53-2307

S T A5 2 0

I s-o

S T A140 I/ I

Y D O O R1

Indicates area of visual inspections. @

S E C T I O N 41L E F T S I D E

FIGL-RE 2. ESTERNAL LAP JOINT CORROSION INSPECTIOS

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age 18

8/14/97

BOEIPL’G SERVICE BULLETIN 747-53-2307

O U T E R S K I N

I N N E R S K I N

clUPOINBDD

T Y P I C A L L A P J O I N T

SECTION A-A

F-IC;I.‘RE 2 EXTERShL L,‘cP.JOISTCORROSIOS ISSPECTION rCONTINUEDt

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AC 43-204Appendix F

0/14/9-i

ENTN O .


STA5 2 0

c-n I STA

C R E W O O O R S T

S T A2 2 0

1 STA

S E C T I O N 4 1RIGbIT SIOE

S T A1 4 0

R Y D O O R1

FIGURE 2. EXTERNAL L.iP JOIST CORROSIOS ISSPECTION ICO~TINLEDI

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3ge 20

747-53-2307

a/14/97 AC43-204Appendix F


E N T R Y D O O R N O . 2W I N G B O D Y FAIRINGS

R I G H T S I D E

S E C T I O N 4 25 2 0

S T A STA5 2 0 741

L E F T S I D EE N T R Y DOOR N O . 2

S E C T I O N 4 2

001 3

FtGURE 2. EXTERNAL LUJOIST CORROSION INSPECTION (CONTISLEDI

Dee 21189 747-53-2307

AC 43-204Appendix F

a/14/97


E N T R Y DOOR N O . 3

S - 2 3

S T A

1 0 0 0

E N T R Y D O O R 1 4 8 0

b A P P L I C A B L E T O RAOOl. RAOOS-RAOl*.

RAlO2, R A 1 0 3 A N D R A 2 0 1 O N L Y .

I N D I C A T E S A R E A O F V I S U A L I N S P E C T I O N O N L Y 10S E C T I O N 4 4

‘1 303

FICL-RE 2. EXTERNAL LAP JOINT CORROSION INSPECTION ICONTINUED)

)ec 21/89 747-53-2307

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8/l/3/97 AC 43-2C4Appendix F

BOEING SERVTCE BULLETIN 747-53-2307

W I NG/BODY

F A I R I N G S

/ E N T R Y O O O R N O . L,

S - 2 3

s - 1 9

S - 2 3

NTRY D O O R

S T A\ S T A

1480WING/BOOY 1 9 6 1 . 1FAIRINGS

S E C T I O N 4 6

FIG

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:RE 2. ESTERUXL L.U'JOISTCORROSION INSPECTIOS ICO?.-TISLED~

747-53-2307

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AC 43-204Appendix F

u/14/97


E N T R Y D O O R N O . 5

/C A R G OD O O R

s - 2 3

s - 1 9

-& --+- BL 0.00

5-4

S - 2 3

FIGL-RE 2. EXTERSAL L4P JOIST CORROSION INSPECTION tCONTI?XED,

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I E N T R Y D O O R m I

S E C T I O N 4 6S T A

1 9 6 1 . 1

Page 24



03 P e r f o r m the f o l l o v i n g a p p l i c a b l e action(s):

a.

b.

C.

d.

c.

f .

For l a p j o i n t a r e a s v l t h c r a c k i n g o r c o r r o s i o n compl?tely t h r o u g h t h eskin, r e p a i r p e r 747 S t r u c t u r a l Repair Manual S u b j e c t 53-30-03 priort o fb. chcr pressur i zed flight

For m i s s i n g o r d i s t r e s s e d fas teners , rep lace fasccner p e r 747Structural R e p a i r Manual S u b j e c t 53-30-03, F i g u r e 9 o r 1 0 , p r i o r t onext pressurized flight.

For lap jo int areas v i t h s k i n b u l g i n g o r pillovlng i n e x c e s s o f0 .010 inch, r e p a i r p e r 7 4 7 Stactural R e p a i r Manual S u b j e c t 53-30-03unless the folloving three conditions have been met :

1. I n s p e c t i o n p e r 767 Non-Destructlva Tes t hnual D6-7170, P a r t 6 ,s u b j e c t 51-00-00. Figure S indicates that mater ia l loss does notexceed 10 percent.

2. N o e v i d e n c e o f s k i n c r a c k s o r c o r r o s i o n c o m p l e t e l y t h r o u g h t h eskin 1s f o u n d .

3. F o r S e c t i o n (+6. t e a r s t r a p s h a v e b e e n r e v o r k e d b y t e m p o r a r yr e p a i r o r terminating a c t i o n p e r S e r v i c e Rull’etin 767-53A2279 i nadjacent area.

NOTE: Adjacent area refers to the area bounded by the 3 stringerb a y s a b o v e a n d belov t h e a p p l i c a b l e l a p j o i n t a n d t h ec l o s e s t t e a r s t r a p forward a n d a f t o f t h e c o r r o d e d a r e a .Where c o r r o s i o n i s v i t h i n 5 i n c h e s of a f r a m e , t h e n e x tdistant tear strap from and not the tear strap closest tothat frame determines that boundary.

F o r l a p j o i n t a r e a s v h e r e m e a s u r e d m a t e r i a l l o s s d o e s n o t e x c e e d10 percent. r e i n s p e c t p e r t h i s s e r v i c e b u l l e t i n a t 5 0 0 f l i g h t - c y c l e sAS s p e c i f i e d i n the p r o c e d u r e (Hethod I o r I I ) b e i n g rued.Terminat ing ac t i on m u s t b e p e r f o r m e d o n c o r r o d e d l a p j o i n t ( f r o mforward c i r c u m f e r e n t i a l Splice t o aft CirCubbferentFAl s p l i c e ) v i t h i n30 months of being found.

For lap joint areas vhere material loss is greater than 10 percent,repa i r per 7&7 St ruc tura l Repa i r Hanual Sub jec t 53 -30 -03 pr i o r t o nextp r e s s u r i z e d f l i g h t .

For any lap sp l i ce vhich i s requ i red t o be repa i red per 7rt7 S t ruc tura lR e p a i r Manual S u b j e c t 53-30-03, terminating action must be performedon the remaining unrepaired length of the sk in pane l ( f r om f o rwardcircumferenclal s p l i c e C O a f t circumferential s p l i c e o f r e p a i r e d s k i npanel) vithln 15 months of the repair. I f e x i s t i n g r e p a i r s a r e f o u n dd u r i n g t h e i n i t i a l v i s u a l I n s p e c t i o n o f this b u l l e t i n , terminatingaction must be accomplished on the remaining unrepaired length of theskin panel within 15 months of being found.

FIGC’RE 2. EXTERNti LX JOINT CORROSION ISSPECTIOh’ (CONTINUEDI

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AC 43-204Appendix F

8/14/97


P12,,I:; FL,

O V E R H E A D P A N E L S

nSTA

1 O B S E R V E R S ’s;ATION

S T A3 4 0

‘PPER DECK

T Y P I C A L FLIGHT OECK II-~STALLATIONA L L A F F E C T E D C O N F I G U R A T I O N S S I M I L A R

FIGURE3. FLIGHTDECKWJOINTINTERh'ALACCESS

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Page 26



69

FIGLZIE 3. FLIGHT DECK LAP JOIh’T INTERNAL ACCESS

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AC, 43-204Appendix F

8/14/97

BOEIKG SERVICE BULLETIN 747-53-2307

6

FIGURE 3. FLIGHT DECKUPJOINT LVTERNALACCESSrCONTINC'ED)

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Page 28



01

02

03

04

05

Remove t h e f l i g h t e n g i n e e r ’ s s e a t p e r 7&7 halncenance UanuaI Subject25- Il.02 or operator’s comparable procedure. Reamve the observer ’ s seatp e r 7~7 M a i n t e n a n c e Manual S u b j e c t 25-11-03 o r o p e r a t o r ’ s c o m p a r a b l eprocedure. R e m o v e t h e crev s e a t p e r 7&7 M a i n t e n a n c e Manual Subject2S-11-05 or operator’s comparable procedure.

Remove the pflot’s seats per 7&7 Maintenance Hanunl Subject 25-11-01, oroperator’s comparable procedure.

Remove the pilots’ overhead pane l P5 and c i rcu i t breaker pane ls P7, Pl2(and P126 i f i n s t a l l e d ) . Reference 71r7 U a l n t e n a n c e Manual Subject31-00-00.

N o t shown - Cover pedestal, panels, rack, And all vlre bundle connectorsvlth plastic sheets to help prevent contmlnatlon or damgage of equipment.

Remove and salvage disconnect panels behind the pilots’ overhead panel P5and circuit breaker panels P7 and PH. Disconnect vlre bundles as requiredto enable dlrconnect panels to be moved c lear o f modl f lcat fon area fordrlpshleld removal.

NOTE : Prior to dfsconnectlng any vire bundles from disconnect panels, removingany vlre bundles from wire bundle clamps or disconnecting any separateg r o u n d v l r e s , eruure t h a t a l l wire bund l es and separa t e vires a r eidentified and suitably marked for relnstallatlon.

06 Remove and sa lvage the overhead sldcvall llnlngs, moldlngr, dripshields,and insulation in flight deck area pe r 767 Ha ln t enance tianul Sub j ec t25-l&-O1 or operator ’s comparable procedure.

07 N o t shown - L o o s e n a n d d e f l e c t a n y i n s t a l l e d p l t o t static t u b i n g a srequired Fn q odlflcatlon areas per 747 Haincenance Hanual Subject 36-11-00or operator’s comparable procedure.

08 Not shovn - Loosen and deflect, or remove any oxygen tubing in modificationareas. as requ i red per 747 Maintenance tk-iua 1 Subject 35-00-00 oroperator’s comparable procedure.

0 9 N o t shown - Remove crev escape hatch per 767 halntenance nanual Subject53-21-01 or operator’s comparable procedure.

FIGCRE 3. FLIGHT DECK LXP .JOIST ISTERKXL ACCESS \CONTISL..D,

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Page 29

43-204

L E F T(IF I

g/14/97

F L I G H T C O M P A R T M E N TA F T P A R T I T I O N

FLICtiT C O M P A R T M E N T O O O R/

El1 R A C K E N C L O S U R EP A R T I T I O N

R I G H T CREY 0

C R E W O O O R: N S T A L L E O 1

F L O O R - M O U N T E

lOOR

E S C A P E S L I D E( T Y P I C A L )

\F O R W A R D L E F TP A R T I T I O N

T Y P I C A L U P P E R DECK C O N F I G U R A T I O NWITH L E F T A N D R I G H T C R E W D O O R

( O T H E R U P P E R D E C K C O N F I G U R A T I O N S S I M I L A R )

C E N T E R LIGtiTEO REVEfL

U P P E R C L O S U R E P A N E L

Appendix E

BOEIKG SERVICE BU-LLETIX 747-53-2307

C L O S U R E P A N E L

S T O W A G E B I N

P S U PANEL-

W I N D O W R E V E A L

FIGLXE 4 L-PPER DECK LAP JOIST ISTERNAL ACCESS

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Page: 30


BOEING SERVICE BULLETM 747-53-2307

01 Remove and salvage equipment and furnishings AS required to gain acctss toSTA 420 through STA 520 lap joints.manual subjects for removal procedure.

Rtftr to the following maintenance

Equip-antHainttnanctManual Subject

Ulndov Rtvt~l 25-21-02Sidewall and Ceiling Insulacion 25-21-04Ceiling Panels 25-22-03Paasengtr Service Units 25-23-01Forward Closets 2S-24-00Forward Right Partition 2S-24-11Forvard bft Partition 25-24-12Crev Rest Area 25-24-19Passenger Seats 25-25-01Wall Mounted Attendant Scat 25-25-04Stalrvay Forverd Right Partition 25-26-02Stair Aft Right Partirlon 25-26-03Stairvay Forverd Left Partition 25-26-06Sidevall Stovtgt Units 25-28-15Overhead S tovrgt Bfns 25-28-23tivatorits 25-40-03Floor Hounctd Esctpt Slide 25-68-02Crtv Entry Door 52-13-01Flight Compartment Door 52-51-01

02 Not shown -the

Install a11 items which are removed in the prtctdlng step perapplicable mainctntnct mtnual subject or optrttor's

procedure.compartblc

FIClJRE 4. L'PPERDECKLAPJOINTINTERN~~ACCESS~CONTIN~ED,

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AC 43-204Appendix F a/14/97


STA2 3 6 0

A T T E N D A N TS E R V I C E P A N E L

/

T Y P I C A L

( O T H E R M A I N

CEJLING P A N E LI

P A S S E N G E R1 S E R V I C E U N I T

S I D E W A L L_- ..1.” ‘“I.&L

O V E R H E A DS T O W A G E BIN

\A M A I N E N T R Y

D O O R O N EI /

MAIN D E C K C O N F I G U R A T I O N

DECK C O N F I G U R A T I O N S SIMILAR)

4

FIGL-RE 5. .MA.lX DECK LAPJOINTINTERNALACCESS

Dee 2 l/89 747-53-2307

age 32

a/14/97 jZC43-204Appendix F


NOTE: TO prevent damage to floor panels. it is recommended that a l/Z-inchthick, l-foot square plywood bearing pad be used under each leg ofladders, stands or scaffolds. Additionally, it is also recommended thatonly one person be allowed to use each ladder, stand or scaffold.

01 Remove and SAlVAse equipment and furnishings AS required to gain access toSTA 140 through STA 2360 LAP joints. Refer to the folloving maintenanceManuel subjects for removal procedure.

EquipmentliaintenanceHanurl Subject

Sidcvall Lining Panels 25-Zl-Ol/-02Sfdevall and Ceiling Insulation 25-21-O&Sidevall Dado Panels 25-21-12Celling Panels 25-22-Ol/-03Entry-day Ceiling Panels 25-22-06Passenger Service Units 25-23-01Attendant Service Unit 25-23-04Forward Closets 25-24-00PArtiKi0l-S 25-26-05Passenger Seats 25-25-01Track llounted Attendant SeACS 25-25-03Wall flounced Attendant Sects 25-25-06Floor Covering 25-27-00Insulation Blankets 25-28-01Overhead Stovage Bins 25-28-23Sidevall Galleys 25-31-MSidevall bvatories 25-GO-01Cargo Lining Panels 25-59-01Attendant Panel 25-23-05Oxygen Tubing 3S-21-00lialn Entry Door No. 1 52-11-01Floor Panels 53-21-02

02 Not shovn - Install all items vhich are removed in the preceding step perthe AppliCAble maintenance manua 1 subject or operator's CornpArAbleprocedure.

FIGI;RE j \vUS DECIi ~~,JOIS~‘ISTERNXI,~~CESSICO~TIN~ED~

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Page 33 (and 34)

W4

AC43-204Appendix G

a/14/97

VISUAL INSPECTION EOUIPMENT

MANUFACTURER OF SUPPLIER

Circon ACM1P.O. Box 1971Stamford, CO 06904(203) 328-8751

VISUAL INSPECTION EQUIPMENT SUPPLIED

Remote viewing instruments and systems:borescopes; borescope video systems; andhigh-intensity light sources.

Fibertron Inc.600 N. Shepherd Bldg. 115Houston, TX 77007(713) 861-3602

Remote viewing instruments: industrialborescopes; borescope video systems; andhigh-intensity light sources.

Instrument Technology Inc.P.O. Box 381Westfield, MA 01086(413) 562-3606Learjet/BombardierPO Box 7707Wichita, KS 67277-7707Attn. Spares Dept.Lenox Instrument Co., Inc.265 Andrews RoadScottsville Industrial ParkTrevose, PA 19047(215) 322-9990


LarascopeXlptical Prism InspectionSystem


Machida Inc. Remote viewing instruments: industrial40 Ramland Road South borescopes; borescope video systems; andOrangeburg, NY 10962 high-intensity light sources.(914) 365-0600 (800) 431-5420

McMaster-Carr Supply Co.P.O. Box 4355Chicago, IL 60680-4355(708) 833-0300

Industrial luminaires: adjustable armlights; portable utility lights;incandescent and fluorescent troublelights; borescopes; fiber opticilluminators and light guides;inspection mirrors; and flashlights.

Mitsubishi Cable America, Inc. Remote viewing instruments: industrial520 Madison Avenue borescopes; borescope video systems; andNew York. NY 10022 high-intensity light sources.

Moritex USA, Inc.6440 Lusk Blvd. Suite D-105San Diego, CA 92121

Newco, Inc.P.O. Box 4013Florence, SC 29502(803) 669-2988



Olympus Corp. Remote viewing instruments: industrialIndustrial Fiberoptics Division borescopes; borescope video systems; and4 Nevada Drive high-intensity light sources.Success, NY 11042-1179(516) 488-3880

Page 2

a/14/97 AC 43-204Appendix G

MANUFACTURER OF SUPPLIER

Optical Gaging Products Inc.850 Hudson Ave.Rochester, NY 14621(716) 544-0400

VISUAL INSPECTION EQUIPMENT SUPPLIED

Optical instruments: optical comparatorsand measuring microscopes.

Optronics EngineeringUniversity Business Center175B Cremona DriveGoleta, CA 93117

Richard Wolf MedicalInstruments Corp.Industrial Division7046 Lyndon Ave.Rosemont, IL 60018(708) 298-3150



Schlueter Instruments Corp.Gunbarrel SquareSuite 320 6525 Gunpark DriveBoulder, CO 80301(303) 530-2217


Shott Fiber Optics Inc.122 Charlton StreetSouthbridge, MA 01550(508) 765-9744


Titan Tool Supply Co., Inc.68 Comet P.O. Box 182Buffalo, NY 14216

Optical instruments: measuring andalignment microscopes; toolmakersmicroscopes; flexible and rigidborescopes; high-intensity lightsources; fiber optic light sources andlight guides; etc.

Welch Allyn Inc. Remote viewing instruments: industrialInspection Systems Division borescopes; borescope video systems; and4619 Jordan Road P.O. Box 100 high-intensity light sources.Skaneateles Falls, NY 13153

Page 3 (and 4)

B/1.4/97 *c 43-204Appendix H

APPENDIX H. ENGINE VISUAL INSPECTION GLOSSARY

Engine Visual inspection Glossary. Retyped witkl Permission ofPratt & Whitney.

Page 1

A':43-204Appendix H

8/14/97

ENGINE VISUAL INSPECTION GLOS!3ARY(Courtesy of Pratt & Whitney)

GLOSSAFtY OF TEXMS: The following defines terms used in this Master andother VIS’s.

Abrasion: A rubbing away of coating material which may or may notexpose base metal.

Back-To-Back Imperfections: Imperfections on the opposite faces of aspecific wall (or weld) which normally are opposite each other (see Figure I I-1). This condition is considered evidence of a single thru-wall imperfection.If it is obvious that d&continuities on opposite faces are caused by the samedefect. Even though offset, this condition is considered back-to-back (seeFigure I l-2).

Figure I I- 1. Single Thru-Wall Figure I l-2. Back-To-Back

Bellmouth: Taper condition formed on ID of a hole at the opposite end ofthe hole from which a punch or blanking die enters.

Blending: An operation which removes an irregularity from a surface,resulting in a shallow, smooth depression.

Blister: A localized 1iRing of coating, plating, fiberglass, or paint,appearing as a bulge that may break when probed.

Bottomed Imperfection: Fit, cavity or hole in which the bottom can beseen.

Braze Crack: Linear fracture of the braze surface.

Braze Fillet: Braze in a joint creating a smooth transition between thedetails being joined.

Braze Joint: Arca between details to be joined by brazing.

Braze Porosity: A group of closely-spaced, small voids (internal pores) inthe braze joint or fillet open to the braze surface.

Page 2

8/14/97 AC 43-204Appendix H

Braze Rippling: A condition of the braze surface characterized byunevenness and irregular appearance with peaks and valleys that aregradual in nature, like ripples on a pond.

Braze Void: Unfilled space in braze material in which a bottom is visible.

Broach Mark A straight depressed imperfection without tears, caused bythe broaching operation (See Tool Mark).

Burnish: A shiny area resulting from rubbing against a hard, smoothsurface; may contain scratches of no apparent depth.

Burnishing: Mechanical smoothing of a surface, usually by rubbing.

Burn Marks: Localized indication of excessive heating (e.g., blue to blue-black discoloration) due to excessive dwell time of a tool at that location, orelectrical arcing due to improper contact between an electrode and the part.

Burn Out: Electrochemical machining erosion beyond the desired featureprofile.

Burr: A fragment of metal which remains attached to the surface after amachining or riveting operation.

Burst: Cracks caused by rupture extending outward from a central point.

Chain Porosity: Porosity in linear alignment.

Chatter Mark: Recurring undulations or irregularities that result fromvibratory interactions of the tool and a typical machined surface.

Chips or Chipping: Discrete particles of a coating which have beenremoved by mechanical means.

Clearly Separated: Imperfections which are not touching when viewedwith the unaided eye.

Cluster: Two or more imperfections, clearly separated, which can becontained within a circle of the maximum diameter allowed by the assignedstandard. A cluster, or group of clusters which can be contained within theallowed circle shall be counted as one imperfection.

Cold Shut: Intermittent or continuous lines caused by unused material.

Corrosion: Surface is pitted and discolored, caused by unwanted chemicalor electrochemical action.

Page3

AC 43-204Appendix H 8/14/97

Crack: Linear imperfection in the form of a narrow break or fissure of thesurface.

Crater: A depression at the termination of a weld bead.

Crazing: A network of minute cracks appearing in the coating of coatedP a - -

Delamination: A separation of the layers in a layered material.

Dent: A surface depression normally having rounded edges, comers, andbottom, caused by the impact of some object.

Depressed Imperfection: Imperfection below the general surface of thepart; may have either smooth or irregular (sharp) edges or bottom (See Dentor Pit).

Die Break or Breakway: A rough surface caused by breaking away ofmetal by a punch or blade during a blanking or shearing operation.

Draw Mark: Linear, trough-like grooves which result from the action ofdie imperfections or foreign material on the drawn material.

Dross: Linear imperfections or imperfections in the form of branching orirregular patterns, caused by impurities or oxides in a cast material.

Erosion: The carrying away of material by the flow of gases, fluids orsolids.

Excess Braze: Braze material beyond the joint fillet; sometimes referredto as a run, streak or flash.

Fissure: Linear imperfection in the form of a narrow separation of surfacematerial.

Flaking: Raised areas of coating or plating on a coated or plated part,indicative of poor bonding.

Foreign Material: Any solid or liquid material not integral to a part.Such material may or may not be adherent to a surface or passage.

Forging Mark: Ridges or grooves on the external surface of a part causedby foreign material or irregularities on the forming die.

Formed Depression: A change in surface level caused by mismatch ofadjoining die segments.

Page 4


Fretting Corrosion: A rapid oxidation of surfaces caused by movement ofclosely fitted parts. It is characterized by surfaces exhibiting colors rangingfrom black to brick red, depending upon severity and/or time of exposure tofretting corrosion.

Fusion Line: Interface of the weld bead and parent metal.

Fusion Zone: The weld bead formed by the melting of filler metal andparent metal, or of parent metal only.

GaIIing: An advanced case of fretting corrosion where there is transfer ofmaterial from one to the other of closely fitted surfaces, causing damage toboth surfaces.

Gas Path: Engine airstream area.

Gouge: Relatively wide trough-like depression caused by tearing away ofthe surface by another object.

Grinding: An operation that removes material by the use of an abrasivematerial to produce a predetermined size.

Groove: A narrow cut in a surface.

Heat Affected Zone: The zone on each side of the weld bead on both theweld deposit and melt thru sides, when applicable. The width of the heat-affected zone shall be one half the width of the weld bead. See Figure 11-3.

HEAT AFFECTED ZONEl/2 WELD BEAD WIDTH

__-__- me-

WELD BEAD

Figure H-3. Typical weld deposit and melt thru sidesPage 5

I\c:43-204Appendix H

8/14/97

Heat Discoloration: Staining, ranging from straw color (‘low temperatureeffects) to purple (high temperature effects).

Hot Tear: Linear fractures in the form of ragged wavy lines of variablewidth resulting from overstress of the material during solidification.

Imperfection: An interruption (non-uniformity) in the normal surfacecondition of a part configuration which must be evaluated for acceptance toan assigned standard.

Inclusion: A linear or non-linear entrapped foreign material particleretained in the metal during solidification.

Incomplete Fusion: A linear imperfection of varying width caused byfailure of the weld material to fuse during a welding operation.

Interface: A common boundary of two pieces,- spaces or phases.

Kink: A buckled condition, a short tight twist or curl in tubing caused by abending or winding of the tubing.

Lap: A linear imperfection caused by folding over of metal edges duringrolling or forging operations.

Linear: An imperfection having a length three or more times its width.

Linear Alignment: Three or more aligned imperfections separated fromone another by less than three times the maximum imperfection dimension.

Line of Braze: Visible braze material in the joint; includes recessed brazeand depressed imperfections in which the bottoms can be seen.

Mqjor Dimension: The longest dimension of an imperfection.

Minor Dimension: The smallest dimension of an imperfection.

Nick: A small surface imperfection having sharp edges, corners, or bottomcaused by impact of a sharp object.

,Nodule: A small, rounded, raised lump of metal, plating or coatingmaterial.

Non-Bottomed Imperfection: A depressed imperfection in which thebottom cannot be seen.

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Non-Linear Imperfection: An imperfection whose length is less thanthree times its width.

Oil Canning: Localized buckling or distortion of a smooth, thin-wallcontour, usually caused by weld mismatch or weld shrinkage.

Orange Peel: A dimpled or grainy surface texture resembling an orangepeel.

Peeling: Section of a coating or plating lifting away from the coated orplated surface.

Per Inch of Weld: One inch of weld bead length regardless of weld width.A shifting of an imaginary scale having one inch increments along the weldis required to contain the maximum number of imperfections in a one inchlength.

Pit: Small irregular cavity in a surface, usually dark bottomed.

Plating Pit: A rounded depression in the surface of the plating which doesnot expose base material.

Polishing: A finishing operation which produces a smooth surface finish.

Porosity: A series of holes or pits caused by air or gas trapped in themetal during solidification.

Raised Edge: A narrow ridge of material along an edge raised above thegeneral contour of the part.

Raised Imperfection: An imperfection which is above the general surfaceof the part.

Recessed Braze: Braze around the joint which falls below the theoreticalfull joint surface.

Rollover: A rounded edge formed on the side of a part from which a punchor blanking die enters.

Run: See ‘Excess Braze’

Scoring: Multiple scratches caused by contact with a mating part, foreignmaterial or tool.

Score Line: A deep scratch caused by an irregular mating surface.Page 7

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Scratch: A linear depression with a sharp bottom caused by movement ofa sharp object or particle across the surface.

Scuffs: Small closely spaced scratches caused by the rubbing together ofhard surfaces.

Seam: Linear imperfection attributable to an unused material conditionwhich existed prior to metal working operations; variation of a lap.

Shallow Imperfection: An imperfection which appears to penetrate thesurface finish texture, does not have a dark bottom and would not cause astylus having a nose radius ranging in size from .030” to .0365” (Steel, TAM167120 or 170194 or equivalent) to hesitate (catch) when passed over it.

Shear Mark (Die Break): A rough surface caused by breaking away ofmetal during die-forming operations.

Shrinkage: Linear or non-linear imperfections of varying forms caused bycontraction during solidification.

Smooth: A surface that is continuously even, free of irregularities,presenting no resistance to the sliding of a finger or tool. Can be applicableto a one plane surface or transition surfaces between planes.

Spalling: Breakdown of the surface (cracking, flaking) due to fatigue,usually in the form of irregular, sharp edged pits with edge conditionsindicating progression. May be caused by subsurface inclusions, in whichcase the bottom of the pit may be dark.

Spatter: Molten material expelled from a weld which adheres to nearbysurfaces.

Stain: Surface discoloration due to liquids drying on the part.

Step: An abrupt change in the surface contour which looks like a step incross section.

Stretch Mark: A condition where material has been elongated duringforming to the point of producing a rippled surface.

Stringer: Impurities in a metal which are elongated by rolling or formingoperations. May appear as a continuous line or a series of elongated pits orinclusions.

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43-234Appendix H

Superficial Imperfection: An imperfection which disrupts the surfaceand appears smooth-edged but does not penetrate the surface roughnesstexture. This condition is so slight, considered less than a shallowimperfection, that a stylus need not be used to evaluate it.

Surface Texture (Finish): The texture of a surface, be it forged, cast, ormachined. Also, this term applies to the numerical value assigned to thesurface roughness of machined surfaces.

Surface Roughness: Marks left on the workpiece by the action of a tool,such as a grinding wheel or a lathe tool.

Tear: Removal of metal by tensile stresses imposed by a dull tool or tooheavy a cut.

Through Void: A void which extends completely through a braze or weld.If it is impossible to see through the void, it is considered through if nobottom can be observed.

Tool Mark: Imperfection, :~s-~ally depressed, caused by machining tools.

Void: Regular or irregular shape imperfections resuking from lack of brazeor weld material.

Warped: Twisted or distorted out of shape because of unequal internalstresses introduced in forming or thermal operations.

Weld Undercut: A groove in the parent metal adjacent to an edge of aweld left un.Elled by the weld operation.

Well Dispersed: Imperfections separated from one another by 125 inchesor more.

Woodgraining: A general surface condition consisting of smooth-bottomed,elongated pits connected by light surface cracks.

Wrinkle: A rippled surface that occurs in areas of sharp contour changesin sheet metal parts.

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