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ATP Grid Index to Manufacturers Publications:

Enstrom HelicopterF-28AMaintenance Manual

Section Topic

General Information

Title PageList of Chapters (Table of Contents)Record of RevisionsRecord of Temporary RevisionsList of Effective PagesService Information Summary

Section 1 Manual Procedures

Section 2 General Information

Section 3 Inspections

Section 4 Weight and Balance

Section 5 Power Plant (Fuel Oil, Oil Ignition System)

Section 6 Main Rotor Hub Assembly

Section 7 Main Rotor Transmission

Section 8 Belt Drive Assembly

Section 9 Electrical Systems and Components

Section 10 Structure

Section 11 Flight Controls

01/25/2008 Copyright Aircraft Technical Publishers Page 1 of 2EN 0120 MM)

Section Topic

Section 12 Furnishings

Section 13 Utility Systems

Section 14 Instruments

Section 15 Tail Rotor Drive Assembly

".k End of Index I~jrk

01/25/2008 Copyright Aircraft Technical Publishers Page 2 of 2

EN 0120 Uh)

IVI FGI

INTRO

MAINTENANCE MANUAL

THIS IS THE F-28A

ORIGINALAs Received By

ATP

Manufactured by The Enstrom Corporation, Menominee, Michigan

Ownership of the F-28A Helicopter will provide you with a smooth,distinctive, and comfortable mode of flight geared to the concept ofmodern transportation. For business or pleasure, the field of opera-tions is practically unlimited, as point-to-point travel can be accom-plished from either prepared or unprepared areas. The distinctiveappearance of the F-28A is symbolic of prestige and its high perform-ance capabilities. Under the graceful lines of the F-28A is a ruggedlyconstructed helicopter designed for easy servicing, minimum main-tenance, dependability and economical operation.

This Reissue Replaces All Previous Issues

Copyright 1972 Enstrom Corporation, Menominee, Michigan, U.S.A.

Price $35.00

Revised 8/18/72

RECORD OF REVISIONS

MFG REVNO DESCRIPTION ISSUEDATE ATPREVDATEI INSERTED BY

LOG OF REVISIONS

Revision Pages RevisedDate

Inserted Removed

12-20-73 MM 9-112-22-74 MM 10-105-22-74 MM 11-75-22-74 MM 11-218-1-74 MM 1-28-1-74 MM 2-48-1-74 MM 3-69-1-75 MM 5-159-1-75 MM 5-169-1-75 1 MM 5-17

NOTE: Revised text is indicated by a black vertical line. I

RECORD OF TEMPOR;9RY REVISIONS

ATP REV INSERT DATE REV REMOVEIREV NO DESCRIPTION ISSUE DATE DATE BY REMOVED INCOR BY

LIST OF EFFECTIVE PAGES

Insert latest changed pages, destroy superseded pages.

Page No. Issue Page No. I ssu e

The asterisk indicates pages changed, added, or.deleted bythecurrent change.

SERVICE IN FORMATION SUMMARY

The following service information has been incorporated in thisManual:

Number Date Number Date

TABLE OF CONTENTS

SECTION 1 MANUAL PROCEDURES PageIntroduction fTable of Contents 1Manual Arrangement 1Aircraft Qffectivity ~1Manual Changes and Revisions 2Alphabetical Index 2

SECTION 2- GENERAL INFORMATION

FZSA Description 1The Helicopter 1Interior Arrangement 1Airframe 1Air Induction System 2Powetpaant aOil System 2Oil Systeni Indicators 2Engine Controls 1 2

Throttle.......... 2Mixture Control

c2

Magneto Switch 2Starter Button 2Master Switch.......; 2

Cabin Heat........; 2Clurc~ Engagement Lever..... 3Fuel System 3

Auxillia~ Fuel Pump Switch 3Fuel Quantity Indicator 3Fuel Pressure Indicator 3

Transmission System 3Knain~Rotor Transmission 3

Temperature Indicator 3Tail Rotor Transmission 4RoSor SyStem 4

ZVl;ain; Rotor L.......... 4Tail Rotor..........~.-.

......~n.......,..4

Rotor Tachometer 4Stab:liztlr 4Flight Controls 4

Cyclic Control 4Collective Pitch Control 4Directional Control Pedals

.......,.9-....i~, 5

Flight instruments 5Airspeed Indicator r....-....~.:a... 5

A

Altimeter 5Compass 5OAT Air Temperature Indicator. 5

Electrical Power Supply System 5Direct Current Power System 5Key to Cndrumerrt Panel 8Electrical Power Panel J

Lighting Equipment. 7Position Lights 7Anti-Collision Lights ILanding Light 7Instrument Panel Light 7

Radio 7Ground Handling Wheels 7Baggage Compartment 7Principal Dimensions of F28k 8F28A Specifications 9Related Publications and Dir;L~ctives Lid i 8-11Service Support Items 12Service Support Ite~ns 13Special Tools.,...., iJSpecial Tools List :rp

SECTION 3 INSPECTIOPIS

Pre-Plight Inspection 3F28A ExteriorF28A Interior 2Exterior Inspection 3

Helicopter Inspection and LubricationCheck Sheet Instructions 4Lubrication Chart 6Helicopter Inspection Sheet 6Helicopter Inspection Sheet 7Helicopter LubricationSheet 8Special inspections F28A 9dpecial Inspections Powerplant i i 30Lycoming 400 Hour Inspection i 10Overhaul Cycles Powerplant 19Limited Life and Component Overhaul Lid

....i .1... --1-9Shim Color Identification Chart 13!Torque Data 13Torque Data 14Torque Data b b i........,,...... 15Torque Data i................. 16F28 Special Torque Data 16

~:Standard Torque Data 17Standard Torque Data 18Standard Torque Data 19

SECTION 4 WEIGHT AND BALANCE PageInformation 1Weight and Balance 1 ITools and Equipment 1Detailed Procedure for Weighing F28A 1Detailed Procedure for Weighing F28A 2

B Weighing Illustration 2Weighing Illustration 3Weighing Procedure 4Sample Weight and Balance Computation 5Station Diagram 6Weight and Balance Report F-166Aircraft Actual Weight Report F-167Aircraft Weight and C/G Calculation F-168........... C6~

SECTION 5 POWER PLANT

Description 1Powerplant Installation and Unit Location Diagram 2Engine Compartment Right Side Photo 3Engine Compartment Left Side Photo............, 3Specifications 4Powerplant Operations i 5

F-28A Normal Engine Starting Procedures 5F-28A Engine Starting Procedures, Hot Condition 5F=-28A Rotor Engagement 5F-28A Engine Warmup and Ground Chede 6F-28A Engine Cooling and Shut Down Procedure 6

Operating Limitations 7Instrument Markings 8

Fuel Injection System 8Description 8Field Adjustments 8-9Injector, External View Diagram 10

Fuel InjectionSystem Trouble-Shooting Chart....-...., 11-12Injection System Service Notes 12

General 12Starting 12Idling 13Shutdown (Cut-Off) 13

Ignition System t,,, 13General 13-145200 Magneto and Associated Components Photo.., 14

Ignition System Trouble Shooting Chart 1617Ignition 17-18Powerplant Trouble-Shooting 18

TroubleShooting Engine 18-21Inspection of Fuel Servo Screen 22Fuel Distributor Valve 22

C.

Oil Cooler 22Oil Cooler and Duct installation Photo 23Removal of Oil Cooler 23Inspection of Oil Cooler 94Leakage Check of Oil Cooler 24installation of Oil Cooler 24-25

Removal of Oil Screen Assembly 25Inspection of Oil Filter Assembly 25Engine Exhaust System 26

Description 26Removal of Exhaust System 26Inspection of Exhaust System 26Installation of Exhaust System 26

Cold Weather Operation Information 27Fuel System 28

Description 28Main Fuel System Diagram 28Removal of External Fuel Booster Pump 29Installation of External Fuel Pump 29Engine Driven Fuel Pump 29Removal of Engine Driven Fuel Pump 29Inspection of Engine Driven Fuel Pump 29Installation of Engine Driven Fuel Pump 30Disassembly of Fuel Strainer 31Cleaning Fuel Strainer Assembly 31Inspection of Fuel Strainer Assembly.........; 31Assembly of Fuel Strainer 31-32Removal of Fuel Tanks 33Installation of Fuel Tanks 33Procedure for Calibration of Fuel Tank Gage 33Leak Repair for F-28A Fiberglass Tanks 34Removal of Fuel Control Valve 35Fuel Control Valve Photo 35Assembly of Fuel Control Valve 35

Filter Induction System 36Description 36-37Filter-induction System Diagram 36Inspection and Servicing Filter 37-38Typical Air Filter Cartridge Photo 37

Cooling System 38Description 38Fan Assembly 38Power Plant Cooling System Diagram 39Removal 40

Mixture Control Rigging 41Mixture Control Removal 41Throttle Control Rigging 41-43

PageThrottle and Mixture Control Diagram 42Throttle Control Removal 44

SECTION 6 MAIN ROTOR HUB ASSEMBLY

Description 1Removal 2Disassembly 2-3Main Rotor Hub Assembly Diagram 2Inspection 3-4Damper Assembly Photo 3Assembly 4-6Main Rotor Hub Assembly Photo 5Installation of Main Rotor Hub on Shaft 6Main Rotor Blade Retention Assembly 6

Description 67Retention Assembly Photo 7Removal 7Retention Assembly Diagram 8Disassemb(y 9Assembly 9-11Installation of Retention Assembly Photo 10Notes on Lubrication i...........:.. 11Installation 12Lamiflex Bearing Change 12

SECTION 7 MAIN ROTOR TRANSMISSION

Main Rotor Transmission 1Description 1

Main Rotor Drive Assembly 1Removal of Main Rotor Shah and Transmission

Assembly 1-2Main Rotor Transmission 2

Disassembly of Main Rotor Shaft Assembly 2-3Rotor Shaft and Transmission Assembly Diagram..... 3Assembly of Main Rotor Shaft Assembly 4-5Pinion Shah 5

Removal and Disassembly 56Build-Up and Installation 67Main Rotor Pinion Shaft Assembly Diagram 7

Installation of Transmission Assembly 8Procedure for Checking Ring and Pinion Backlash and

Rotor Mast Run-Out 8Pinion Assembly Removal Photo 8Main Transmission Servicing Points Photo 9Tooth Patterns 10Main Transmission Sight Gage Photo 11

t

SECTION 8 BELT DRIVE SYSTEM Page IBelt Drive System 1

Clutch Engagement System 1Description 1

Belt Removal Procedure 1-3Idler Pulley and Support Assembly Diagram 2Belt Installation Procedure 3Removal of-idler Assembly from Helicopter 4Installation of Idler Assembly 4Disassembly of Idler Pulley From Yoke 4Assembly of Idler Puney to Yoke 4Removal, Disassembly and Inspection of Belt

Roller Assembly 1 4Part Replacement, Assembly and Installation of

Belt Roller Assembly 4Belt Tension Assembly Diagram 5 1Removal of Belt Engagement Mechaniwr from

Pylon 6,Inspection of Belt Tensioning Unit 6Installation of Belt Engagement Mechanism......... 6Clutch Control Handle 6

Jack Strut and Pulley Assembly 7Removal of Upper Pulley Assembly 7Jack Strut and i)ulley Assembly Diagram 8Removal of Jack Strut ii..... 9Inspection of Jack Strut and Lower Pulley Assembly 9Installation of Upper Pulley Assembly 910Installation of Jack Strut and Lower Pulley 10

Adjustment Procedure 10-11Clutch Control Adjustment Diagram 11Tracking Idler Pulley 12Idler Pulley System Photo 13

SECTION 9 ELECTRICAL SYSTEMSAND COMPONENTS

Electrical Systems and Components 1I

Description 1Battery 1Electrical System 1 UV)Removal of Battery 1 1

Battery Installation Diagram 2Alternator and Voltage Regulator 2 iRemoval of Alternator 2-3Removal of Starter 3Alternator and Staiter Location Photo 3 1Removal of Voltage Regulator 3.Voltage Regulator Adjustment (NI-CAD Battery) 4 1

PageElectrical Installation System 4-5

Electrical Installation System Locstions Diagram.:;. 5Electrical System 6

Starter Button 6Electrical System Troubleshooting Chart........... 6-8Night Flying Lighting System 8

Instrument Lights 9Night Lighting Kit Installation Diagram 9Night Flying Lighting Installation Troubleshooting

Chart 10Lamp Replacement Guide Chart 10Flight Ampere Load Conditions Table 11Electrical Wiring Installation Panel (Rear. View) Photo 12Electrical Symbols Diagram 13Electrical Schematic F-28A Diagram 14

SECTION 10 STRUCTURE

Structure 1Description 1Pylon Assembly 1

Inspection of Pylon Assembly 1 2Cabin Assembly 2

Description 2Removal 2

Removal of Left and Right Door Assembly......:.. 4To Replace Glass in Doors 4Installation of Door Assembly 4Overhead and Lower Bay Windows 4

Removal 4installation 4

Windshields 4Removal 4Installation 4

Baggage Compartment 5Removal 5Installation 5

Glass Enclosures Diagram 5Tail Cone Assembly 6

Description 6Removal of Tail Cone Assembly 6

Removal of Tail Cone Torque Tube Extension 9Assembly 9

L

PageLanding Gear Assembly 9

Landing Gear Removal 9Landing Gear Installation ...,.........-I 9Landing Gear Assembly Diagram 10Skid Shoes 11

Description 11Removal 11Installation 11

Ground Handling Wheels 11Description 11Removal 11

Landing Gear Attachments Photo 12Wheel Bar and Ground Handling (Lowered

Position) Photo 12Oleo Struts 13

Description 13Proper Placement of Jack Under Vertical

Bolt Head Photo............., 13Removal From Helicopter 13Support in Proper Place When Jacking Helicopter

For Removal of Landing Gear 14Disassembly 14-16Oleo Strut Assembly Diagram 15Assembly .16Installation 16-17

Oleo Extension Photo 17Inspections 17

Corrosion Control 18Information 18Corrosion Prevention--Salt Water/High Humidity 18Corrosion Problems in Agricultural Application ~18-19Corrosion on Aluminum Alloys............, 19Corrosion on Alloy Steels 19Exterior Surface Touchup Treatment 19-20Surface Touchup 20-21

SECTION 11 FLIGHT CONTROLS

Flight Controls 1Description 1Flight Control System Diagram 1:Pilots Collective Control Stick 2

Removal 2!Pilots Collective Stick Diagram 2;Installation 2-3

Collective Pitch Control Stick 3

~-t

PageGo-Pilots Collective Control Stick 3

Removal 3Go-Pilots Collective Stick Diagram 4

Collective Trim System 4Removal 4-5Collective 8ungee Tool Injtallation Photo 4Collective 8ungee System Diagram........... 5Rigging. 6Installation 6Location of Collective Bungee Photo 6Collective Controls Diagram 7

Cyclic Pitch Control Stick 8CyclicSticks 8

Removal 8Installation 8

Cyclic Controls 9Lateral and Longitudinal Trim Motors Removal 9-11Lateral and Congitudinal Trim Motor Assembly

Photo 9Lateral and Longitudinal Trim Motor Assembly

Photo 10Cyclic and Collective Control Rigging Procedure 11-13

Cyclic Control System Diagram- 12Cyclic Azimuth Check Verification of Rigging 14Swashplate Assembly 14

Description 14Removal 14-15Inspection of Lower Swashplate Assembly 15-17Swashplate Assembly Diagram 16Assembly of LowerSwashplate Unit 17Removal and Disassembly of Upper Swashplata

Unit 17-18Swashplate Assembly Photo 18Inspection of Upper Swashplate Unit 18Assembly of Upper Swashplate Unit 19

Main Rotor Blade Tracking Procedure....i..... 19-21

Procedure for Setting Autorotation 21Main Rotor Drive System 21

Main Rotor Drive System Vibration Troubleshooting Chart t... 21-22

SECTION 12 FURNISHINGS

Furnishings IIDescription 1

-L

Page -!:13SECTION13 UTILIPI SVSTEMS

Utility Systems 1 ICabin Heating System 1

Heater Shroud 1Valve Assembly 1Troubleshooting Cabin Heating System 2Cabin Heating Diagram 3Cargo Hook Diagram 4

SECTION 14-INSTRUMENTS

Instruments 1Instrument Panel.... 1

Description 1-3Instrument Panel Photo 4

Instruments and Systems Troubleshooting Chart 5Airspeed Indicator 5Compass 5-6Altimeter 67Engine and Main Rotor Tachometer Indicator 7Fuel Quantity Gage 7-8Engine Oil Temperature Indicator .;....i... &9Fuel Pressure and Oil Pressure Gage 9Cylinder Head Temperature Indicator....... 910Ammeter 10Gea;box Oil Temperature Indicator 10

Pitot-Static System 10Dexri ption 10-1 2Pitot Static System Diagram 11Pitot Tube 12Instrument Lines 13Instrument Lines 14

SECTION 15 TAIL ROTOR DRIVE ASSEMBLV

Tail Rotor Drive Assembly 1Description 1Tail Rotor Assembly Photo 1Removal of Tail Rotor Assembly 2Disassembly of Tail Rotor Assembly 2-3Cleaning Tail Rotor Assembly 3-4Tail Rotor Assembly Diagram 3Assembly of Tail Rotor Assembly 4-5Removal of Control Assembly 5Tail Rotor Control Photo 6Disassembly of Bearing Housing 7

J

PageReassembly of Bearing Housing 7Tail Rotdr Pedal Controls 7

Removal, Inspection and installation 71

Tail Rofor Pec~l Push-Pull Rods 7Removal and Replacement 7

Tail Rotor Mechanical Contr~ls Diagram....... 8Tail Rotor Bellcrank 9

Removal and ReCilacement 9Tail Rotor: Gear Box Removal 9

Removal....;....1 --9

Disassembly ofTail Rotor GearBox 9Removal and Disassembly of Input Shaft 9-11Tail Rotor Gear Box Assembly 10Removal and Disassembly of Output Shaft 11Tail Rotor Gear Box Input Capsule Photo. 12Tail Rotor Cable-lnspectio~ and Replacement i13

Tail Rotor Olive Shaft Assembly 13Tail Rotor ~ableAfsembly Diagram 14Tools.and Equipment Necessary to

Perform Operation 15Removal of Tail Rotor Drive Shaft, Pillow

Assemblies, and Mechanical Tachometer 15Inspection of Tail Rotor Drive Shah

Assembly~.......... 15-17Tail Rotor i)ri~ie Assembly Diagram 16Assembly and Installation of Tail Rotor

Drive Shah and Pillow Block Assembly 17Installation of Mechanical Tachometer 17-181Alignment of Tail Rotor Drive Shaft -3~.;;... 18Final Inspection of Tail Rotor Drive

Assembly 18Reinstallation.of Tall Rotor Drive Assembly 18-191

Tail Rotor System 19Tail Rotor Rigging Procedure 19

Tail Rotor Rigging Photo 20Tail Rotor Lubrication Points Photo 20Tail Rotor Rigging ToolPhoto 21

Tail Rotor Balancing Static 21Tail Rotor Balance Photo 22

K

SECTION

MAN UALPROCEDU RES

SECTION

Manual Procedures

MM-1-1

INTRODUCTION

This Maintenance Manual is one of the group of publications thatcomprise a complete information file for the Enstrom F-28A Helicoptermanufactured by the Enstrom Corporation, Menominee, Michigan.The information presented is intended to provide maintenancepersonnel with information and procedures necessary to repair andmaintain the aircraft in flying commission.

TABLE OF CONTENTS

The table of contents at thebeginning of the Manual presents, insequence, the principal text headings within each section, a completelist of illustrations, also in numerical order.

MANUAL ARRANGEMENT

Information is presented by text and illustrations under sectionheading. The descriptive text far the major systems defines thefunction, location, and physical characteristics.

Operating instructions are included when required to perform specificmaintenance tasks. Instructions identify and locate switches, lights,and indicators and give normal sequence of operation.Maintenance procedures are presented as a group in continuoussequence; a general statement of the type of maintenance that canbe performed is made at the beginning of each group. Proceduralgroups contain all or part of the following, as applicable:

Testing or operational checkTroubleshootingAdjustmentRemoval

CleaningInspectionRepair, parts replacement, or fabricationPart repair, testing, and adjustmentInstallation

Under each type of maintenance heading the following informationis provided, if applicable:

Toolsand equipmentMaterialsMaintenance procedures

AIRCRAFT EFFECTIVITY

The Manual is written to include all configurations applicable to theEnstrom F-28A~Helicopter. Aircraft differences are determined byserial number and appear as effectivity notes on affected ~illustrationsand in related text. Where no effectivity notesappear, it may be

MM 1-2

assumed that the configuration shown or discussed is applicable toall aircraft.

MANUAL CHANGES AND REVISIONS

Subsequent to the publication of the initial issue of the Enstrom F-28AHelicopter Maintenance Manual, changes in aircraft and equipment,in support concepts and in procedures, as well as information developedby experience, affect the contents of the Manual. To ensure thatcoverage in the Manual continijes to reflect such changes, revisedinformation is released by one of the following methods:A. Revision An alteration of portions of the Manual accomplished

by the replacement, addition and/or deletion of pages.CAUTION: Do not discard the present Manual when a revision

is received. Consult the "A" page to determineusability of old pages to prevent having a publi-cation with missing pages.

The "A" page that accompanies each revision lists all pagesreplaced, added, or deleted. The Manual should be disassembledand all affected pages removed and destroyed. The replacingand added pages should then be inserted and checked against the"A" page I isti ng.

B. Reissue In cases where large numbers of changes are involved, acomplete reissue of the Manual is warranted. Preceding issues ofthe Manual then becomes obsolete and should be discarded.

C. Service Information Notices and Letters Service informationis to be.considered as part of the Manual.

C.-l Service LetterTo be used to transmit information, recommendations andgeneral service instructions to the customer.

C.-2 Service NoteTo be used to direct the customer to make mandatory changes,improvements or inspections to his aircraft.

C.-3 Physical incorporation in the Manual of the service infor-mation will be accomplished at the next revision date andlisted on the Service Information Summary page.

ALPHABETICAL INDEX

The alphabetical index at the end of the Manual is the users primaryguide for locating information. As such, it is arranged to provide readyaccess to specific procedures. Subj:ects are listed alphabetically.

Revised 8-1-74

SECTION

GENERALINFORMATION

SECTION

2

General Information

MM-2-1

F-28A DESCRIPTION

One of the first steps in obtaining the utmost performance, service,~nd flying enjoyment from your F-28A is to familiarize yourselfwith its equipment, systems, andcontrols.

THE HELICOPTER

The Enstrom F-28A Helicopter is designed for high performance,mechanical simplicity, and maximum versatility.. By virtue of com-ponent longevity and minimum maintenance requirements, the F-28Aenjoys the lowest operating cost of any helicopter. The rugged,rotor head, combined with the (51 Ibs.) rotor blades, give unheard-ofstability and excellent autorotational characteristics.INTERIOR ARRANGEMENT

The cabin interior is a full, three-place, side-by-side seating arrangementwith a spacious 61" width for maximum pilot and passenger comfortand safety. The wide choice of interior color styling is available tocomplement any exterior combination. The instrument panel is onthe horizontal plane for more natural scanning and is convenientlylocated for dual pilot viewing. Simple, clean controls blend tastefullyinto the interior. Excellent visibility is offered through the clearview tinted Plexiglas wrap-around windshield and doors to overheadand lower deck windows. Extra-width, swing-open doors closesecurely with simple-to-operate safety lock handles.

AIR FRAME

The airframe is composed of three main sections: the tail coneassembly, cabin assembly, and pylon assembly.The tail cone assembly is a semi-monocoque structure and attachesto the pylon assembly with three bolts for easy removal and installa-tion. The rear of the tail cone supports the horizontal stabilizer,tail rotor gear box, tail rotor, and tail rotor skid.

The cabin is fabricated from molded fiberglass and is an integral unit.It is attached to the forward side of the pylon assembly by six boltsand encompasses the structural aluminum seat portion plus instrumentpanel, cyclic, collective, and tail rotor controls. The wrap-around,tinted Plexiglas windshield and full glass doors, plus upper and lowerdeck windows, provide for excellent visibility. The extra-width,swing-open doors close sedurely with simple-to-operate safety lockhandles. The helicopter can be flown with either left, right, or bothdoors off.

The pylon structure assembly is fabricated from steel tubing andhouses the engine, the belt engagement and idler assembly, clutch,cooling fan, fuel tanks, and main rotor drive system. A skid-typelanding gear attaches to the lower section at four points. Groundhandling wheels are provided for moving the helicopter, or can beeasily removed. Four air-oil struts soften landing loads and aid

MM-2-2

in leveling the helicopter while on the ground.AIR INDUCTION SYSTEM

The air induction system consists of a filtered non-ram carburetorair intake located beneath the engine compartment. It incorporates aspring-loaded, automatic alternate air source.POWER PLANT

A Lycoming HIO-360-CIA-205 HP four cylinder opposed engine isused in the F-28A Helicopter. The engine is delivered with platinumspark plugs.

NOTE: It is recommended that the appropriate LycomingOperators Manual be consulted prior to any adjustmentor repair to the engine.

OIL SYSTEM

The Lycoming engine employs a wet sump lubrication system. It hasa capacity of 8 quarts. A bayonet-type oil quantity gauge withgraduated markings is part of the oil tank filler cap and is accessiblethrough the left-hand side cowling of the engine. Engine oil cooling isaccomplished by an oil cooler with thermostatic valves and by-passprovisions. It is located on the right-hand side of the enginecompartment.

Oil System Indicators Oil Temperature and Pressure Gauges. Standardtype gauges are provided for both the engine oil temperature and oilpressure indications. Both gauges are marked to provide visual engineoperating limitations and are located on the instrument panel.ENGINE CONTROLS

Throttle. A twist-grip type throttle is located on the collective pitchcontrol stick for direct control of engine power. It is manuallyconnected to the fuel servo-throttle valve on the engine.Mixture Control. A mixture control push-pull control knob isprovided on the center of the console. It is pushed in during allflight operations. Shutting off the engine is accomplished by placingthe mixture control in the Idle Cut Off position.

Magneto Switch. The magneto switch is a key-operated switch locatedin the center of the instrument panel. For starting, place the switchin the Both position.Starter Button. The starter button is located on the end of thecollective control. Push to engage.

Master Switch. The master switch is located on the instrument panelnext to the master switch circuit breaker. It is a single-throw, two-position switch.

CABIN HEAT

The cabin heat control is located at the left-hand side of the pilotsseat, on the floor. By moving the control in or out, the operator

MM-2-3

regulates the amount of cabin heat through the output louvers locatedin the center of the floor under the instrument panel.CLUTCH ENGAGING LEVER

The clutch engagement lever is located at the right side of the pilotsseat on the forward face of the seat structure. The clutch lever is

provided as a means of engaging and disengaging the rotor drivesystem

FUEL SVSTEM

The system consists of two interconnected fuel tanks, which feedsimultaneously to the engine. Each tank must be filled individually.They are located on the left and right side of the aircraft over theengine compartments. The tanks are fabricated of fiberglass and havean individual fuel capacity of 15 gallons each. Each fuel tank is gravityfed to a central distributing line which connects to the electric boosterpump and engine driven pump. The fuel control valve is an off-on typeand is located on the firewall next to the pilots left shoulder. Eachtank has an individual drain valve in the bottom. There is also a mainfuel filter located aft of the firewall in the engine compartment. Thecontrol is on the right-hand side of the engine compartment andextends beyond the side panel.

Auxilliary-Fuel Pump Switch. The fuel booster pump switch and fuelpressure warning lights are located on the instrument panel.Fuel Ouantity Indicator. The fuel quantity gauge continuouslyindicates the total quantity of fuel; It is hooked up through a simpletype liquidometer float located in the right-hand fuel tank.Fuel Pressure Indicator. The fuel pressure indicator provides PSIpressure readings of the fuel as delivered to the flow divider.\ Theindicator is marked for normal operating range from 0 12 PSI.

TRANSMISSION SVSTEM

The main transmission unit provides an 8.7871 reduction ratiobetween the engine and the main rotor. The transmission incorporatesa free-wheeling unit in the upper pulley assembly, which is mountedon the output pinion shaft. The free-wheeling unit provides a dis-connect from the engine in the event of a power failure and permitsthe main and tail rotors to rotate in order to accomplish safe auto-rotation landings. Five and one-half pints of No. 90 wt, oil are used inthe transmission. The main rotor transmission has a sight gauge whichis located on the aft right-hand side and is visible through an opening inthe baggage compartment. A vent line is located on the forward sideof the main rotor transmission. Positive oil pressure is maintained, tothe main thrust bearing, by centrifical force of the ring gear. All otherbearings are splash fed.Main Rotor Transmission Temperature Indicator. A main rotortransmission gauge is located on the instrument panel and is redlinedat 2200F.

MM-2-4

Tail Rotor Transmission. The tail rotor transmission, a right-angletransmission mounted at the aft end of the tail cone, supports anddrives the tail rotor. The tail rotor transmission transmits power fromthe tail rotor drive shaft to the tail rotor assembly through steel spiralbeveled gears housed in an aluminum alloy housing. The tail rotortransmission is equipped with a self-contained lubricant supply andlevel gauge at the rear of the housing and a magnetic plug can beremoved to inspect for metal particles. Its capacity is 5 oz, of No. 10Ioil. Large sight gauge indicates full with ship leveled.ROTOR SYSTEM

Main Rotor. The main rotor is a three-blade, fully articulated system;that is, the blades are hinge-mounted to be free to lead-lag, flap, andfeather. The fully articulated system in the F-28A Helicopter providessmooth control responses in all modes of flight; and due to the kineticenergy stored in the heavy rotor blades, allows for easy-to-perform, safeautorotation landings in the event of power failure. The rotor assemblyis mechanically simple and consists of three all-metal bonded blades,upper and lower rotor hub plates, universal blocks, blade gripassemblies, and lead lag hydraulic dampers. The excellent hydraulicdampers govern the lead-lag motion and aid in the dynamic stabilityof the F-28A.

Tail Rotor. The tail anti-torque rotor counteracts the torque of themain rotor and functions to maintain or change the helicopter heading.The tail rotor is a two-bladed, teetering, delta-hinge type assembly.Each blade is connected to a common hub. Blade pitch change isaccomplished by movement of the pilots directional control pedalsthat are connected to a pitch control assembly mounted on the tailrotor 900 gear box. This blade pitch provides control of torque andchange of directional headings. Power to drive the tail rotor is takenfrom the input shaft of the main transmission.Rotor Tachometer. The rotor RPM indicator is part of a dual-purposetachometer which also reads engine RPM.

Stabilizer. An all-metal, fixed-position stabilizer adjusted to a -40 isinstalled on the tail cone assembly for longitudinal stability.FLIGHT CONTROLS

Cyclic Control. The cyclic control stick is similar in appearance to thecontrol stick of a fixed-wing aircraft. The direction of stick movementresults in a change of the plane of rotation of the main rotor and willproduce a corresponding directional movement of the helicopterthrough the longitudinal and lateral modes of flight. The stick gripincorporates a trigger-type switch used for radio transmissions. A trimswitch is also located on the cyclic stick grip to control the longitudinaland lateral trim forces.

Collective Pitch Control. The collective pitch control lever is locatedto the left of the pilots position and controls the vertical mode offlight. The amount of lever movement determines the angle of attackRevised 8-1-74

MM-2-5

and the lift developed by the rotor blades and results in an ascent ordescent of the helicopter. A rotating, grip-type throttle is located atthe end of the collective control.

Directional Control Pedals. The directional control pedals are locatedin the cabin forward of the pilot and/or co-pilot. When moved, theseadjustable pedals change the pitch of the tail rotor blades and therebyprovide the method of changing directional heading.

F L IGHT I NSTR UM E NTS

The standard flight instruments which are installed in the F-28A asbasic equipment comply with the requirements under visual flightrules for day or night~operation. The panel arrangement providesease of visual observance and includes space provisions for installationof additional instruments to meet individual requirements.

Airspeed Indicator. The single-scale airspeed indicator is calibrated inMPH and provides an indicated airspeed reading at any time duringforward flight. The reading is obtained by measuring the differencebetween impact air pressure and the static vent. The pitot tube, whichprovides the impact air pressure source, is located forward of the cabinnose section. Static air pressure for instrument operation is derivedfrom two static vents located on either side of the rail cone assembly.The openings in the pitot tube and static vent ports must be maintain-edobstruction-free and clean at all times for proper instrument

operation.Altimeter. The altimeter is a sensitive type that provides distance-height readings from 0 to 25,000 feet. The long hand in a singlecomplete sweep of the dial totals 1,000 feet, and the short handtotals the thousands of feet altitude. The instrument is vented tothe same static port vents as the airspeed indicator.

Compass. A standard aircraft quality magnetic compass is mountedon the front of the cockpit within easy sight of pilot or co-pilot.It is to be used in conjunction with a compass correction card locatedadjacent to the instrument.Free Air Temperature Indicator. The free air temperature indicatoris a direct reading, bi-metallic instrument with a stainless steelprobe. This instrument provides ambient temperature informationwhich, when utilized, will assist i-n determining performance capabili-ties of the helicopter at the existing climatic condition. The indicatoris located in the top of the canopy.

ELECTRICAL POWER SUPPLY SYSTEM

Direct Current Power System. The basic power supply system is a12-volt direct current system, with a negative ground to the helicopterstructure. A belt-driven alternator is located on the aft part of theengine and is used in placeof a generator. One 12-volt battery islocated in the right-hand side of the pilots compartment and servesas a stand-by power source supplying power tothe system when thealternator is inoperative.

MM-2-6

-i~

I:E i

I:ORIGINAL

As Received ByATP

~e

~R

KEY TO INSTRUMENT PANEL

1 Manifold pressure/fuel pressure 16 Engine hour meter2 Fuel quantity 17 Clock3 Oil pressure 18 Panel light4 Main rotor gear box 19 Running lights5 Oil temperature 20 Anti-collision light6 Ammeter 21 Landing light7 Cylinder temperature 22 Alternator switch8 Radio circuit breaker 23 Panel light circuit breaker9 Altimeter 24 Running light circuit breaker10 Airspeed 25 Anti-collision light circuit breaker11 Rotor/engine tachometer 26 Landing light circuit breaker12 Panel light dimmer switch 27 Ignition circuit breaker13 Ignition switch 28 Instrument CL circuit breaker14 Master switch and circuit breaker 29 Trim motor circuit breaker

15 Fuel pressure indicatorand boost pump switch

MM-2-7

Electrical Power Panel. The following switches and circuit-breakersare located on the right-hand side of the instrument console withineasy reach of pilot or co-pilot: landing light, navigation light,position light, alternator, instrument light, and master switch.LIGHTING EOUIPMENT

The basic helicopter is equipped with the required lights necessary forVFR night operation plus additional lighting equipment for utility andconvenience purposes. The electrical panel on the right-hand side ofthe instrument console contains the protective circuit breakers andcontrol panels for the lighting equipment.Position Lights. Two position lights are located one on either side ofthe forward cabin structure and two lights are located aft of thestabilizer on the tail cone.

Anti-Collision Lights. The anti-collision lights have a rotating,flashing action that provides for adequate identification of thehelicopter. One anti-collision light is located on top of the fuselageaft of the cabin, and the other light is located forward of the cabinstructure under the pilots compartment. They are operated by theanti-collision switch located on the panel.Landing Light. The landing light is of the permanent extend type andis mounted on the unders~pe of the cabin structure and setin thedesired angle for the best forward illumination. The switch foroperation of the landing light is located on the instrument panel inthe electrical console section.

Instrument Panel Lighting. Three lamps located under the glareshield give maximum visibility with minimum glare.RADIO

The radio is located on the right-hand side of the instrument panel.A circuit breaker is located to the right of the radio. A transmissionswitch is located on the cyclic stick. The radio jack box is locatedon the forward face of the firewall behind the pilots rigHi-handshoulder.

GROUND HANDLING WHEELS

Eac~i landing gear skid tube Ras provisions for easily installed Id~binggear wheel assemblies. Each assembly has a manually operated ~ver-,centering device to lift the skids for iristallation of the wheel~ orretracting them for flight. ihe ground handling wheels should beretracted and the helicopter allowed to rest on the skids when en~inerun-up is being peiformed or when helicopter is parked.BAGGAGE COMPARTMENT

Thk compiartmenr for storage of baggage Is provided in the tail coneasse~nbly aft of the engine compartment. Access to the area iSthrough a single door located on the right-hand side and has a lockfor external locking. The capacity of the compartment is approxi-

i;: mately 10cu. ft. and has an allowable loading capacity of 60 Ibs.

O=IC,

fP3 54.5"O

u,336" (28.0)

O-h

r,

s(p 219" (18.25)m

3

192" (16.0) RADIUSa

3.,n

r; 201 Si4TIC DROIPi0 48.7" MAX. FWD. C.G.o

23" STATIChI::b oz.o" b 93.75" (7.81

.-.-_ I1l.o 72" (6.0) MIN. DROOP~1[ 73.5" (6.125) MAX. AFT C.G.ii 4.0 1 cc-----------337" (28.083)---------------1 96" (8.0)i

78.63 16.55.)1

351.6.. (29 3.)3:

do38" (7.333!

MM-2-9

F-28A SPECIFICATIONS

Power Plant

Type Lycoming OpposedDesignation H10-360-CIACylinders 4Normal power 205 HPNormal RPM 2900 RPM

Specific fuel consumption .5 Ibs. hp/hr.Weight 322 Ibs.Oil 8 qts. 15 Ibs.

Performance

Maximum speed 112V,,Best rate of climb 58 m. p. h. I.A.S.Normal fuel capacity 30 U.S. gal. 176 Ibs.Rate of climb at sea level 950 FPM

Hovering ceiling IGE ft. 5600

Operating RPMs

Engine .2900Tail Rotor 2365Main Rotor 330Main Rotor Autorotation Range 313 385

Ratios

Lower to upper pulley 1:1.226Main Rotor Gear Box 1:7.154Tail Rotor Gear Box 1:1Engine to main rotor 8.7871

Dimensions

Width (overall) 28 2"Rotor diameter 32Height (overall) 9Length (overall) 29 4"Cabin width at seat 61"Tread Landing Gear 7 4"

Rotor SystemNumber of blades 3Chord each 9.5"Disc area 804sq.ft.Main rotor RPM 330Tail rotor diameter 4.67Number of blades 2Chord 3.375"

NOTE: Listed are publications and directives considered helpful when used in conjunction with this manual.r

UNIT NUNIBER TITLE ADDRESS

m

Engine 60297-12 Operators Manual Lycoming DivisionH10-360 Williamsport, Penn. C

Fuel injection 15-3388 Fuel Injection The Bendix Corporation rSystem Systems

Aerospace DivisionBendix Product

South Bend 20, IndianaZv,

Fuel Pump Boost 8110 Maintenance and Weldon Tool Co.Overhaul of 3000 Woodhill Road 2Weidon Pumps Cleveland, Ohio 44104

ignition The ABCs of the The Bendix Corporation ~JBendix Shower of Syntilla DivisionSpark Sydney, New York -I

Vibrator L-557 Overhaul and The Bendix CorporationMaintenance of Syntilla Division rVibrator Sydney. New York

UNIT NUMBER TITLE ADDRESS

Magnetos L-609-1 Installation. The Bendix CorporationOperation, and Syntilla DivisionMaintenance Sydney, New Yorkinstructions for the

8-1200 Series andS-200 Magnetos

Voltage Regulator ASF-7201

Alternator ALY-8403

Starter M 2-4206 Test PrestoliteSpecifications P. O. Box 931

Toledo, Ohio 43601

Battery (OPS) CA-15 Instruction Sonotone CorporationManual Battery Division

Elmsford, N. Y. 10523

Battery (STD) AC78M Exide Power SystemsP. O. Box 5723-CPhiladelphia, Pa. 19120

SERVICE SUPPORT ITEMSAvailable from

Specification Item Enstrom Corp. Source

Aeroshell 14 Grease 5 Ib. can Shell Oil Company1 Ib. can P. O. Box 120

Tulsa, Oklahoma 74100

Aeroshell 16 Grease 5 Ib. can Shell Oil CompanyMIL E-25760 1 Ib. can P. O. Box 120

Tulsa, Oklahoma 74100

Aeroshell "W" Engine Oil Quart or case Shell Oil CompanyAviation gr. 80 Winter P. O. Box 120Aviation gr. 100 Summer Tulsa, Oklahoma 74100

SAE 10W Oil Quarts Shell or Texaco Oil Co.

MIL H5606A Hydraulic Oil Gallon Texaco Oil Company

HD-SAE80-90 Gear Oil 38 Ib. can Mobil Oil Company1547 S. 38th StreetDTE -Su mmer Clutch Oil 1 pt.Milwaukee, Wisconsin 53215

ArcticC-Winter Clutch Oil 1 Pt.

L-45 Grade 20 Damper Silicone Oil 1/2 pt. Union Carbide10421 W. Seven Mile Rd.Detroit, Michigan

Available from

Specification Item Enstrom Corp. Sou rce

MGH 10 Mirror Glaze Plastic 8 oz. bottle Van Duzen CompanyPolish 1/2 gal. can A/C Supplies

CA 151 PL Carbu retor 1 eachAir Filter

AC-A53C AC

AFD-5 PurolaterAutomotive Supply

Andok B Grease 1/2 Ib. can Humble Oil CompanyP. O. Box 1353Houston, Texas 77001

MRn-2-~4

ORIGINALAs Received By

ATP

5~

SPECIAL TOOLS

MM-2-15

SPECIAL TOOLS LIST

NOTE: Special tools may be purchased from TheEnstrom Corporation, Menominee, Michigan,Attn: Parts Department.

Item Nomenclature Part No.

1 Wheel Bar, ground handling T-30012 Wrench, 28-14256 thrust nut T-00033 Wrench, 28-14001 retention nut T-00047 M/R Track Kit, 3 reflectors T-00088 Pin Guide, M/R Blade T-00099 Wrench, Trans Pinion Nut T-0010

10 Hoisting Sling, 3,000 Ib. capacity T-001111 Tail Rotor Rigging Tool T-001212 Socket, retention thrust nut T-001313 Grease Injector Adapter T-001414 Wrench Damper Shaft T-001515 Wrench Swash Plate Gimbal T-001616 Hoisting Eye T-001717 Mandril Assembly T/R Balancing T-001918 Wrench T/R Box Input Nut T-002019 Retainer Collective Spring Capsule T-002221 Tab Bender T-002622 Gage, Tab Angle T-002723 Wrench, Tail Rotor Spindle T-003325 M/R Spindle Sleeve Bonding T-003526 Blade Grip Seal Tool T-003628 Wrench Retention Nut (new type) T-004830 Pinion Nut Wrench T-0053

Revised 3/22/72

SECTION

INSPECTIONS

SECTION

3

Inspection Procedures

MM-3-1

PREFLIGHT INSPECTION

This checklist is designed to be used as a reference guide while per-forming the preflight inspection. Thorougly familiarize yourself withthis Manual before utilizing this checklist. Prior to starting the completepreflight inspection, check the following items in the cockpit: batteryswitch OFF, magneto switch OFF, all other switches OFF,~fuelvalve ON.

F-28A Exterior

CAUTION: Remove all covers and locking devices1. Check left hand door for security.2. Check windshield for cracks.3. Check pitot tube for obstructions.4. Check landing lights, beacon and navigational lights for operation

and security.5. Check irrduction intake scoop for obstructions,6. Check right hand shock strut-piston extension should be 3/0" to

13/4!from red line-struts clean and tires properly inflated.7. Check right hand landing gear for security.8. Check right hand door for security.9. Drain fuel sump.

10. Check right hand engine compartment.11. Check air intake scoop for obstructions.12. Check right hand fuel tank FULL 100/130 octane cap

secured.

13. Check main gear box oil level.14. Check baggage door locked.15. Check right hand static port opening unobstructed.16. Check tail cone for general condition.17. Check tail rotor drive shaft for security.18. Check stabilizer for security.19. Check left and right position lights for operation and security.20. Check tail rotor pitch links for binding or looseness. Check tail

rotor blade for security and leading edge for nicks, bondingseparation and general security.

21. Check tail rotor guard for damage and security.22. Check left hand static port opening unobstructed.23. Check main rotor blades for nicks, bonding separation or

looseness.24. Check main rotor pitch links for binding or looseness.25. Check cyclic and collective walking beams for security.26. Check blade dampers for proper security and oil level.27. Check left hand fuel tank FULL 100/130 octane cap

secured.

MM-3-2

28. Check engine oil 6 quarts minimum, 8 quarts maximum.29. Check fuel system for leaks.30 Check exhaust manifold for cracks and looseness.31. Check engine for oil leaks.32. Check belt drive system.33. Check left hand shock struts-piston extension should be 3/0" to

13/4" from red line-struts clean and tires properly inflated.34. Check left hand landing gear for security.

F-28A Interior

1. Check and adjust rudder pedals.2. Check seat belts fastened or stowed.

3. Doors latched.4. Set collective full down.5. Check clutch disengaged.6. Check throttle CLOSED.7. Check mixture IDLE CUT OFF.8. Check fuel valve ON.9. Check magneto switch OFF.

10. Radio switches OFF.11. Set master switch ON.12. Check fuel quantity.13. Check fuel pressure warning light (press to test).14. Check trim motors for operation.15. Check controls for freedom of operation.16. Set altimeter.

MM-3-3

&13~Bii;;li

I j C

I A~r

ii

ri

r \I

1vI

i"19t IIidi Iifdi 1 :Iiii ii

i

i5~::k;.IC, E,x"r r nII! 1?,I

i i XI.8.~f ti

tid,F

Ii1 j r

ijI

ii j:\k itt:; eti s,B

Zhaa-

~i_

I/

EXTERIOR INSPECTION

MM-3-4

HELICOPTER INSPECTION AND LUBRICATION CHECKSH EET I NSTRUCTIONS

These check sheets are designed to be used as a "Reference Guide"when performing inspections; the sheets when completed may bekept as a permanent part of the helicopters records. Adherence toMaintenance Manual information is mandatory and should be consultedwhen utilizing this check sheet. Each periodic inspection includes everypreceeding inspection; the 100 hour periodic inspection includesall 50 and 100 hour items. A complete lubrication check sheetmust accompany the signed inspection check sheet.

OVERRUNNING CLUTCH SERVICE INSTRUCTIONSThree screws are provided in the flange of the overrunning clutch.Turn clutch until two screws are horizontal and the thirdscrew isabove. Remove the top and one of the bottom screws. Oil shouldseep out of lower hole. If oil does not seep out, add oil through tophole with a spring-type oiler. Reference lubrication chart page MM-3-6.

REMOVE

O1L LEVEL

UNSCREW TOCHECK

OVERRUNNING CLUTCH

LUBRICATION CHART

(QI

U

/o"~liO

o O100 HOURS 25 HOURS

MM-3-6

ENSTROM HELICOPTER LUBRICATION CHECK SHEET

Serial Na. chulll~l

N 411drl~

Total Time:

EngineAirframe 25 !10 IIW P,ri~rlil: SI*SiJI

Lubricate the following items ar rfated. See lubrication cnart in Maintainance Mantlal far exact lervice;loint~.

1 3-~ ~-IZr~E r c6 t6DESCRIPTION i.. 1- :I

I r~y:t C OESCRIPIIONPH P1 rZu I: z:GREASE: AEROSHELL 14 (G-403) SAE 10W

2 TilRotorCouplinpl 100 1 I It Tail Rotor Gear Box (Changc) 5 or. 100 1 I I I2 Clutch FlaxCable 1002 Gwnd Handling Whul IHand PeLI 100 NOTE: Ua 2 drop oil on (I controh 100

Hingn. Locb. Ctsha 100 Vo i drop oil on Trhomnr Shaft 1002 TailRotor(Lubriutsl 252 TailRotor rPu~) 50 HYDRAULIC O1L MIL-H-5606A

18 Main RotorHub ILubnonl 25 PETROLEUM BASE18 Main RotorHub(Purgal 100 4 LandingGalrStrut. AWurequind3 Main Rotor Bum 25

1 DrivoSyatam Lo~nrGtrutBurinp 255 Tail Rotor DrivaShmBringl ZY AEROSHELL GREASE 16 SPEC.

MIL-G-25760A

1 BltRol*r 100GEAR LUBRICATE: MOBIL OIL EPSAEBO-90 ENGINE LUBRICANT

Add oilt Main RmorCrBor IChanpa) tOO Tamp. SinpleViu. Multi-Virc. nquind.Normal uprity 5W pintl (Aboa 60 F.) 50 40-50 Crain and

SOCONY-MOBIL. SUMMER- DTE HEAVYI 30 BOF. 40 40 refillMEDIUM OIL WINTER ARTIC "C" D -70 F. 30 400r20/30 mry50

hoon.1 OmRunningClutd, 100 FUEL AVIATIONOCTANE

1M)/t9O. 30 pallon. sapcity

Revised 8-1-74

MM-3-7

ENSTROM HELICOPTER INSPECTION SHEET

Sarial No. Ovrner

N L~ddress

Total Ti~llc:

Lnllillr Circle type of insDection:AirtralnP 50100 Periodic Special

S: P-14=I 16: ~Ei9--c- cc cc rE^ :9 CON4TURE OF INSPECTION NITURE OF INSPECIION %:C :DI:I

~PPz: r, I: m;

MAIN ROTOR GROUP I I I Raord Eompnaion check: 100II) IZ) 191 14)

Inrpest rotor head for freedom... srurl or (00other damage. I I I I Check alternator min belt andom X" def*ctiom. 50In~psf math plan for Iso~iva wear. too I I I Check cooling tan for lone or bent bledn (00lntpast drive ~yltsm componantr for cracks or other 100 1 I I Chackfan hubtorcrsdcl. 100dmepa.

Check oil coder and linsl for sradu. leaka and 50Inrpast main rotor blada for ~cratcheo. nnt hola at 50 Iwonar and dehrir and obmunion.tip obanuction leading edps for exceoius marand bmion. Check engine cooling hroudforcrackrand loaansu 100Dmpn: Check for avidence for ion of fluid and 100 I I I Check air filter ammhly. clean and replace filnr 100attach poinn for ssurity. cartridge.

Chack rotor blade track. if necanary. (00 100Check engine breather for ob~tructionChack drag linb for looeanera. 100Chack pitch arml for loaenen and rcurity. 100 1 I CABIN GROUPCheck purhgull roQ for clrna. 100

Check uat bsltl for nrhmnt andCheck main rotor pitch lint, for hinding and looennr 100 (W

Chsdcslutckanpspsmsnt 1WCheck Min driva clutch control ryr(am. (00Check all cmtrol~ for trelom.

Check main collactin frnmr hearing for freedom 100 100ISealad Baarinp) inspect windhield for crack. dtrioration. 50

Chesk Dynaf1ex BUlhinp, Irod and in lomr p~nh 1M) I I I In~pstdoorhrdrvn. attachmentrandcrackr 1 (00pull dog in for detariontion.l

EXTERIOR FUSELAGE GROUPPOWER PLANT GROUP

Cheer pitot tube for obnrucfion and scurity. 100Check baffln for crsskl and tight fit to sylind~rr 100Check cylindn for cracked or broken finl. 100 I I Check T/R sabla for mar and proper tmion. 100Check air sntrlncs~ and eritl for deformity. 10D I I I Check operation of navigation lighn: landing liphtl 50

and bUMI.Remove and clean fuel Ersn. fuel mo. (00Check Mpneto~ for timing and lyns. cheer point 1W impact all mldad tube mustuna for local corroaion 100

end cracka.openinp. Check retard for oparation.

Check tell rotor guard attachment and tube for (00Check angina mounting boltl and buhhnn, for ~s 100crackl and loorsnn*

curitv.Check rpark plug aIbom and hieldinp nun for 100 Check tail cone and nabilinr rsmMy for ocurity 100

and ufny.lwrenen.

Crain and refill oil lump. 1 50 1 I I npestallsowlinp for attachmenn. in~pstirlcoopl. 100Ramon and clean oil ucrnnr. 50

Crain and claan main fuel Itrainsr. and check tusl 50 1 TAIL ROTORGROUPvents

Chack tail rotor drin Ihatt Iplim couplingl for 50Check intaka and sluun lyrtam~ for recurity and 50 1 I excenin pnar laakr.IaakI.

Pull and plup in tail rotor tnn~- 100Check muffler for creckr. 50 minion. -lr

Inrpect anline for oil leakage. 50 I Chssle 1etsrinll brin(ll for rouphnon. 50Inrpect rafaty win, of all drain plum and cown. 50 1 I I Check blade condition for damage. srrk. and bond 1 50In~pect iniactor unit and fual line connactiona. 50 I I I ing.Check angina sontrob for trarsl and frr oparation. 50 1 I I Check hub for tacurity to I~h. 50

Rplre or clean rperk plum. 100 1 I I To impact feathsring baring~ for brinelling andluhrisation, dimonnct pitch lint. and rotate hlada 50Check ignition harmer for braakr. 100 2 or 3 turnr.

Chack rpharical bearingl. rod end in lowar puh pull dog in for claaranss Form No. F170on Ipharisal diameter.

MM-3-8

CZ~E a:E c.1~6 FE^:P :pNATURE OF INSPECTION zas c;le~ NATURE OF INSPECTION

r,r

I~ HHb oTAIL ROTOR GROUP (continued) I I I I Chair tail rotor gu box oil lereI DailyChs~ tail rotor nssle it neossary. 100 I I I C?edc Min psu box oil *uel DailyChc~ tail rotor control for rippinp if neossry. 100 1 I I for oil Iee*apaon lor~l.pl(mahp*ana). 100Inspect trmtfer on control yo*e for ass of 501 I I InrpM input pinion drire ul to~ ba*ge. 100morament.

LANDING GEAR GROUP

ELECTRICAL GROUP I I I I Ched( landinp 0aer for cradu in r~ld ass. bolts at 1Wall aMsh ad pirot pints for xopin mn.

Inrpn all electrical riri~ for pmsl condition and 100prop mchongs. Inrpa rraplata a PiLfa~aPinmu Irplaes 100

s ncsnary.Chss~ radio and instruments for propr opration. 100

Impact landinp mar ola. attach points. oil laarlg. 100ChacL battery for 50 1 I I corrosion ad proper extension. ISs Maintananca

Msnuil)Chsk battery terninals. 50Chss* battery for *rtrolytlend specific pravity only 50 1 I I BELT DRIVE GROUP ASSEMBLYit laad +id battsry i imta(lad. 50 I I Chc~ free whrlinp clutch for smptb opsrstion. 1W

For Nisad Rannin SI* Mnufasturs lnstructiomChair condition of drive belt ad st proper tamion. 100

TRANSMISSION GROUP CMe belt rolla for proper clearance. 50Chec* nugnotic plug in main rotor tramrnission. 100

Cbah jrh strut torlspmionot bondandvald 100Chsde condition of pear teeth in main rotor trah 100arsas Raplra a speratad or srastad.

rmiuion. (Sea Maintanaca Manuall

NOTES: Each poensirs inqMion inolvds mary pcadi~ impction (xlmpk: the 100 hour inspection includes all 50 and (00 houri(smJ. IZ) A complatd bbrisotion rhaet must rcompany the lipned inapostion form

It is csnitiad mat this helicopter hs been thorouphly intpestsd pr hndboo~ of msincanncs intruetnns end found to be lirnorthy. andepproprieta entria made in tha halicoptarl logboo~. It is turther cartified that the hlicopter conformm to FAA Ipsifiutian. mat 1II FAAairworthinss direaina ad mice bullatim hna ban compl*d ~im. and the helicoptell pprn me in propr ordar.

MECH.SIG. RATING

DATE PILOT SIG. (if rsquindl

MM-3-9

SPECIAL INSPECTIONS

F-28A Helicopter

Item Paragraph

NOTE: Prior to overhaul of any vendor component, it is suggestedthat an up-to-date manufacturers manual be obtained.

MM-3-1c

SPECIAL INSPECTIONS POWER PLANT

INSPECTION RECOMMENDATIONS FOLLOWING OVERSPEEDOF AVCO LYCOMING ENGINES (Ref. Service Instruction No. 1023C,May 19, 1967.)The engine Model HIO-360-C1B overspeed limitation is 3200 RPM, andit is recommended that the following inspections be performed.For engines that have not exceeded the overspeed limitation, noinspection is required.Engines that have exceeded the overspeed limitation should be removedfrom the aircraft, disassembled and the parts completely inspected.Replace all parts that are not within maximum service limits as shownin Avco Lycoming Service Bulletin No. 268. In engines that employdynamic counterweights, the bushings must be replaced in both thecounterweights and the crankshaft. Engine must have connecting rodbolts and nuts replaced.

LYCOMING 400 HOUR INSP~CTION

In addition to the items listed for daily pre-flight, 50 hour and 100hour inspections, the following maintenance check should be madeafter every 400 hours of operation.Valve Inspection. Remove rocker box covers and check for freedomof valve rockers when valves are closed. Look for evidence of abnormalwear or broken parts in the area of the valve tips, valve keeper, springsand spring seats. If any indications are found, the cylinder and all ofits components should be removed (including the piston and connectingrod assembly) and inspected for further damage. Replace any partsthat do not conform with limits shown in the latest revision of ServiceBulletin No. 268.

OV E R H AU L CYC L ESPOWER PLANT

Component Overhaul AtLycoming Engine 1000 hrs.(Ref. Lycoming letter 1009M dated 3/6/68)

LIMITED LIFE AND COMPONENT OVE RHAU L LIST

NOTE: Components listed shall be removed from the helicopterat the periods specified, in accordance with FAA requirementsas they are limited life items, Overhaul of components must beaccomplished in accordance with the manufacturers instructions.

MM-3-11

Part Life Overhaul CycleNomenclature Part No. (hours) (hours)Main Drive Belt 675-L35 or LD-719 1200

Belt Idler 600Pulley Bearing (MRC-202ZZ)

Swash Plate MR C5201 SE KZZ 1200Bearings New Departure

Z993L13X3B 1200

Damper Assembly 28-14264 500

Tail Rotor 28-15120 4500Blade Assembly

Belt Strut 99608X3B 600Bearings (upper)Lycoming engine 1000 (Ref.

Lycoming letter1009 M dated9/6/68)

NOTE: Prior to overhaul of any vendor component, it is sugge~tedthat an up-to-date manufacturers manual be obtained.

MM-3-12

SHIMS COLOR IDENTIFICATION CHART

INFORMATION: The following color codeing is used on all plastic shimsused on the F-28A Helicopter.

.0005 .001 .0015Silver Amber Purple

.002 .003 .004Red Green Tan

.005 .0075 .010Blue Transmatte Brown

.0125 .015 .020Black Pink Yellow

.025.030

SolidCora I

White

MM-3-13

The following information defines the formulas and methods used to calculatetorque when an adapter is used on the wrer Methods of physically applyingforce to the wrench are discussed with the a,.., of eliminating erroneous readingand torque.

When adapters or extensions are to be utilized, do not use a torque wrenchconstructed so that the position of the applied load can be varied on the frame orhandle.

EFFECTIVE LENGTH, WRENCH AND ADAPTER 1L A)

.i --------L 90"Tw sr

Ta( v ~TI Ijl

Effective length, wrench and adapter

EFFECTIVE LENGTH, WRENCH AND CURVED ADAPTER (L A i

i 906

Effective length, wrench with curved adapter (L A)

TW: Scale reading on wrench.

Ta: Torque (force at end of adapter).A: Length of adapter.L: Length of wrench lever.F: Force

C: Conversion constant

to obtain- Torque produced at the end of adapter, calculate as follows:Ta= (L+A)xF

Twto obtain- Force required on wrench handle, calculate as follows: F

Ta Tw x (L+A)to obtain-- Torque at end of the adapter, calculate as follows:

NOTE: The length of the adapter will increase the capacity of the wrench indirect proport its relation to the fixed length of the wrench.

MM-3-14

EFFECTIVE LENGTH, WRENCH WITH OFFSET ADAPTER i L2 A2

A2-1- L2-

90"

:Ii 1

LI------------l

Effective length, wrench with offset adapter (Lp A21

Valves listed apply only to cadmium plated bolts and nuts coated withmolydisulphide.

2. Bolts, washers, and the surfaces they bear on shall be clean, dry, and free oflubricant. Parts lubricated at the factory need not be cleaned before installation.

3. In some cases, when tightening castellated nuts, the cotter pin holes will notline up with the slots in the nuts. In such cases, the nut may be overtightenedenough to line up ~the nearest slot with the cotter pin hole, but the maximumapplied torque must not exceed the values listed.

4. Bolts and screws with strength of less than 125.000 psi do not require amandatory torque value. The nut-bolt combination shall be tightenedto make satisfactory joint.

5. Bolts and screws with strength of 160,000 psi minimum or higher shall be perNo. 1, unless otherwise specified standard torque values.

C~

-.J~J

6

6

-czui

Wrench with adapter at right angle.

MM-3-15

3-009

Wrench with stirrup-type handle

3-010

Incorrect force application

PALM GRIP HANDLE

3-011

Wrench with palm grip

3-012

Wrench with palm grip and extension

MM-3-16

To obtain- Adapter length when the desired torque is known, calculate asfol lows:

(Ta Tw) xLA=Tw

To obtain- Scale reading on the wrench when the desired torque is known,calculate as follows:

Ta x LTw

L+A

To obtain-- Conversion constant which is a ratio of the lever length of thewrench to the total length of the wrench and adapter, calculateas follows:

C=L+A

To obtain- Actual torque at the adapter using the constant, calculate asfollows:

TwTa

To obtain- Actual torque reading of the scale when the torque at the adapteris know, calculate as follows:

Tw Tax C

CAUTION: Torque readings will be inaccurate if the formulas are appliedwhen using a torque wrench with a rigid handle.

Adaptors which conform to the aforementioned sentence above in no wayaffect the calculations previously described.

TABCE 3 4 TOROU E DATA

SPECIAL TORQUE DATA

PECULIAR TO F-28A ROTORCRAFT

Nomenclature Part No. Torque

Tail Rotor Output ShaftRetention Bolt AN7-H8A 300"/lbs.Tail Rotor Spindle Nuts SL61N-4 50/lbs.Tail Rotor Input Shaft N04 50/ltjs.Main Rotor Gear Box PinionNut SLW3045 2000 PSl"/lb5. +100"/11

0 "/IUpper Main Rotor ShaftHub Retention Nut 28-1400.1 400/lbs.Lower Main Rotor ShaftCarrier Nut 28-13121 333/lbs.Blade Spindles RetentionNut 28-1 4335 12"/lbs.

STANDAR D TO RQU E VALU ES

This table covers standard torque values for National Fine and National Coarse nuts and bolts and tube nuts.All special torque values will be defined on applicable drawings and as noted on parts pages.

Torque Values for Nuts and Bolts (inch pounds) National Fine"

Column 1 Column 2 Column 3 Column 4 Column 5Tap Size Tension Nuts Sheat Nuts 90,000 PSI in (60% of Column 4)

AN 365, AN 310 AN 364, AN 320 Bolts, AN 365 AN 364 andand AN 310 Nuts AN 320 Nuts

8-36 12-15 7-9 20 1210-32 20-25 12-15 40 25

1/4-28 50-70 30-40 100 605/1 6-24 100-140 60-85 225 1403/8-24 1 so-1 90 95-110 390 240

7/16-20 450-500 270-300 840 5001/2-20 480-690 290-410 1100. 660

9/1 6-18 800-1 000 480-600 1600 9605/8-18 1100-1300 600-780 2400 14003/4-16 2300-2500 1300-1500 5000 30007/8-14 2500-3000 1500-1800 7000 4200

1-14 3700-5500 2200-3300 10000 60001-1/8-12 5000-7000 3000-4200 15000 90001-1/4-12 9000-11000 .5400-6600 25000 1 5000

+Torque Values are derived for oil free cadmium-plated steel threads.

Standard Torciue Values Continued

National Coarse"

Column 1 Column 2 Column 3 Column 4 Column 5Tap Size Tension Nuts Shear Nuts 90,000 PSI in (60% of Column 4)

AN 365, AN 310 AN 364, AN 320 Bolts, AN 365 AN 364 andand ~AN 310 Nuts AN 320 Nuts

8-32 12-15 7-9 20 1210-24 20-25 12-15 35 21

1/4-20 40-50 25-30 75 455/1 6-18 80-90 48-55 160 100

3/8-16 160-185 95-100 275 1707/1 6-14 235-255 140-1 55 475 280

1/2-13 400-480 240-290 880 5209/1 6-12 500-700 300-420 1100 650

5/8-11 700-900 420-540 1500 9003/4-10 1150-1600 700-950 2500 15007/8-9 2200-3000 1300-1800 4600 2700

"Torque Values are derived for oil free cadmium-plated steel threads.

Standard Torque Values Continued

Tube O. D. Wrench Torque Range Tube 0. D. Wrench Torque Range(inches) for Tightening Tube (Inches) for Tightening Tube

Nuts (inch pounds) Nuts (inch pounds)

Alum. Allay Steel Alum. Alloy Steel281 12H .5280 281 /2H.5280

1/8 3/4 300-500 430-5753/16 30-70 1 500-700 550-7501/4 40-65 50-90 1-1/4 600-9005/16 60-80 70-1 20 1-1/2 600-9003/8 75-125 9011 50 1-3/41/2 150-250 155-250 25/8 200:350 300-400

SECTION

VVEIGHT ANDBALAN C E

SECTION

Weight BalanceProcedures

MM-4-1

WEIGHT AND BALANCE

INFORMATION

All helicopters are designed for certain limit loads and balanceconditions. Changes in equipment which affect the empty weightcenter of gravity must be recorded in the aircraft and engine logbook. It is the responsibility of the helicopter pilot to ensure thatthe helicopter is loaded properly. The empty weight, empty weightC.G. and useful loads are noted on the weight-balance sheet includedin this Manual for this particular helicopter.

NOTE: Tile C.G. range for the F-28A Helicopter is 92.0" to98.01 from datum line at a maximum gross weight of2150 Ibs. Listed on page FM-3-5 is a typical loadingcondition of the F-28A Helicopter, both rearward C.G.and forward C.G. condition.

WEIGHT AND BALANCE

The removal or addition of fuel or equipment results in changes tothe center of- gravity and weight of the aircraft, and the permissibleuseful load is affected accordingly. The effects of these changesmust be investigated in all cases to eliminate possible adverse effectson the aircrafts flight characteristics. The horizontal referenceweighing point is located 20 inches forward of the center bolt inrear skid attachment.

Maximum Gross Weight 2150 Ibs.Empty Weight (no accessories, fuel or Oil) 1450 Ibs.Useful Load 700 Ibs.

Approved Forward C.G. Limit Station 92Approved Aft C.G. Limit Station 98

TOOLS AND EQUIPMENT

Tape Measure CommercialScale (two) 1000 Ibs. capacityScale tail tone) 100 Ibs. capacityLevel bubble-type CommercialWork stand As required

DETAILED PROCEDURE FOR WEIGHING F-28A SERIESHELICOPTER

a. Thoroughly clean helicopter.b. Helicopter will be weighed inside a closed building to prevent

errors in scale readings due to wind. Helicopter will be placed ina level flight attitude.

c. Check for proper installation of all accessory items. Check todetermine if the scales that are being used have been calibratedrecently, and check to see that the scales will zero out beforeweighing helicopter.

MM-4-2

d. The helicopter will be weighed without fuel, but the weight andbalance record will reflect corrections to indicate the amount ofunusable fuel required by the helicopter configuration. Thehelicopter may be weighed with full oil or without oil, but theweight and balance report should be corrected accordingly.

e. Tare will be noted when helicopter is removed from the scales.

NOTE: Check oil level of main transmission and tail rotortransmission. Check to see that the main rotor bladesare in uniform position, 1200 apart.

f. Close and secure both doors, left and right hand sides.

g. Hoist or jack helicopter clear of ground.h. Position two main scales beneath the skids.

i. Position a pipe nipple in the center of left and right hand scalesat 20 inches forward of center bolt in rear skid attachment.(Detail No. 1)

i:--

ORIGINALAs Received By

A ATP

I: o-

MM-4-3

NOTE: Side panels must be removed for leveling. After leveling,temporarily install for weighing.

j. Height of tail to be adjusted for level.k. Level fore and aft to be taken at lower pylon tube, left side, so

identified. (Detail No. 2)I..lateral level taken at lower forward pylon tube.

ORIGINALAs Received By

ATP

m. Small scale will be located under tail rotor guard at the center lineof the tail rotor output shaft, shown above.

CAUTION: Exercise care to maintain scale alignrrient duringlowering operation of helicopter on scale. No part of skid shouldtouch scale. If helicopter doesnt balance on pipe nipples,under skids as necessary to obtain balance, and measure fromrear skid attachment center bolt to center of pipe nipple.Record measurement on weight sheet.

n. Using jack, raise or lower tail as required to level the aircraftalong the longitudinal axis, paying attention to the level on thelongitudinal and lateral pylon tubes.

MM-4-4

o. Read and record weight from each of three scales.p. Calculate weight and center gravity on attached form, with

weight data. Empty weight will be "dry weight."q. All items added or substracted will be listed on the attached

form with weight, arm, and moment.

CAUTION: Weight and measurement readings are critical.Double check results.

r. Remove helicopter from scales.

CAUTION: Do not remove curbing, jack, nipples, blocks,etc., from scales. These items constitute tare weight.

s. Read and record tare weight from each of the three scales. Anofficial weight and balance report is prepared in connection witheach helicopter presented for airv\lorthiness certification at theEnstrom Corporation. All these reports are marked "actualweight."

t. This weight and balance report, and equipment list will be preparedandsupplied with each helicopter.

u. Use Form No. F-165 Basic Weight and Balance Report to give youa continuous history of weight changes throughout the life of yourhelicopter.

NOTE: Under normal operating conditions, ballasting is notnecessary.

MM-4-5

SAMPLE WEIGHT AND BALANCE COMPUTATION

Approved CG Range: Maximum Gross Weight:92.0 to 98.0 2150 Ibs.

TYPICAL LOADING

Approved Rearward C. G.

Weight Arm MomentBasic Empty Weight 1450.0 100.8 146160.00

(including undrainableengine oil, gear boxoil and unusable fuel)

Engine Oil 15.0 96.0 1440.00

Fuel, 30 gal. 180.0 98.0 17640.00Pilot 140.0 68.5 9590.00

1785. 97.9 174830.00

Approved Forward C. G.

Basic Empty Weight 1450.0 100.8 146160.00(including undrainableengine oil, gear boxoil and unusable fuel)

Engine Oil 15.0 96.0 1440.00

Fuel, 29.2 gal. 175.0 98.0 17150.00Pilot and Passengers 510.0 68.5 34935.00

2150. 92.9 199685.00

~ROTORE

4_

iII C.ENTE.R OFII

r~- I r BQ-ci I I rn\irvLIMITS98

I Y

56" Rotating beacon92

92" Fwd. c/g limits96" Oil arm in engine

6698" Aft. c/g limits

172" Rotating beacon230" Aft. tail cone bulkhead

320" c/g tail rotor

Y-6

WEIGHT AND BALANCE REPORT

320.018

w LCG

J i~I C.G. ~b I----~-- T.R.

DATUM LINE IIf- 113.446 ----7-~7/

If 93.446 7WL WR

.Model Serial No. Registration No.----------

FWD. clg limit 92.0" AFT. c/g limit 98.0"

Weigh point Scale--)bs. Tare Net wt. Arm Moment x 1000

Left gear (WL)

Right gear (WR)

Tail (WT)Total

\1\17-(320.018) (WL+WR) (93446)LCG

Wr+WL+WR

Date Weighed by

Form No. F-166

AIRCRAFT ACfUAL WEIGHT REPORTMode) Serial No, Reg. No.

Standard equipment not installed Optional surplus equipment inat weigh-in aircraft at weigh-in

Moment X I I I I IMoment XItem No. Wt. Arm 11000 in./lbs. Item No. Wt. Arm r1000 in./lbs.

Total 1 I I I I Total

Weighing witnessed by Date

C~-d B PormNo. F-167

AIRCRAFT WEIGHT AND C. G. CALCULATIONModel No. Serial No. Reg. No.

Weight Arm MomentIbs. in. 1000 in./lbs.

Weight las weighed)

Less: optional surplus weight

Plus: missing std. equipment

ComputedTotal weight empty std. aircraft

Actual

Plus: engine oil

Plus: optional equipment kits

Total basic weight

Form No. F-168

Lf- b

SECTION

POWER PLANT

SECTION

Powe rp la nt(Fuel, Oil, Ignition Systems)

MM-5-1

POWER PLANT

DESCRIPTION

The HIO 360 series are four cylinder, direct drive, horizontally opposed,air cooled engines.In referring to the location of the various engine components, the partsare described in their relationship to the engine as installed in theairframe. Thus, the power take-off end is considered the front andthe accessory drive end the rear. The sump section is considered thebottom and the opposite side of the engine where the shroud tubesare located the top. Reference to the left and right side is made withthe observer facing the rear of the engine. The cylinders are numberedfrom front to rear, odd numbers on the right, even numbers on theleft. The direction of rotation of the crankshaft, viewed from the rear,is clockwise. The direction of rotation for accessory drives isdetermined with the observer facing the drive pad.

Cylinders. The cylinders are of conventional air celled constructionwith the two major parts, head and barrel, screwed and shrunktogether. The heads are made from an aluminum alloy casting with afully machined combustion chamber. Rocker shaft bearing supportsare cast integral with the head along with housings to form the rockerboxes for both valve rockers. The cylinder barrels, which are machinedfrom chrome nickel molybdenum steel forgings, have deep integralcooling fins and the inside of the barrels are ground and honed to aspecified finish.

Valve Operating Mechanism. A conventional type camshaft is locatedabove and parallel to the crankshaft. The camshaft actuates hydraulictappets which operate the \jalves through push rods and valve rockers.The valve rockers are supported on full floating steelshafts. The valvesprings bear against hardened steel seats and are retained on the valvestems by means of split keys.

Crankcase. The crankcase-assembly consists of two reinforcedaluminum alloy castings, fastened together by means of studs, boltsand nuts. The mating surfaces of the two castings are joined withoutthe use of a gasket, and the main bearing bores are machined for useof precision type main bearing inserts,

Crankshaft. The crankshaft is made from a chrome nickel molybdenumsteel forging. All bearing journal surfaces are nitrided.

Connecting Rods. The connecting rods are made in the form of"H" sections from alloy steel forgings. They have replaceable bearinginserts in the crankshaft ends and bronze bushings in the piston ends.The bearing caps on the crankshaft ends are retained by two bolts andnuts through each cap.

NOTE: Remove cowling as required for access to enginecompattment.

MM-5-2

Engine lifting eye

Pylon asembly

Oil Cooler

Alternator Startera-

:irX

-C i~e

i!~A Engine mount

~nerm.rtalic by-p~rr uabr,F,,I screen and:temperature probe

_i o1200 8 200

-~-1 --L Series Magnetos

Mixturecontrol lever

Boort pumpO

Throttle lever I Fuel servo controlAC engine driven pump

Fuel Flow Divider

Oil Coaler

POWERPLANT INSTALLATION AND UNIT LOCATION

MM-5-3

FUEL

ELECTRICAL RELAP*NEL

OIL

FUEL FILIER

:Mx:t

ORIGINALAs Received By ENGINE COMPARTMENT RIGHT SIDE

ATP

sREF.ANK

ENGINEBAFFLING

~ilii- i.SEF.V_St_TP~T;E.EG

irREF. F1LTER ASSY.

ENGINE COMPARTMENT LEFT SIDE

MM-5-4

Pistons. The pistons are machined from an aluminum alloy. Thepiston pin is of a full floating type with a plug located in each end ofthe pin. Depending on the cylinder assembly, pistons may be machinedfor either three or four rings and may employ either half wedge orfull wedge rings.Accessory Housing. The accessory housing is made from an aluminumcasting and is fastened to the rear of the crankcase and the top rearof the sump. It forms a housing for the oil pump and the variousaccessory drives.

Oil Sump. The sump incorporates an oil drain plug, oil suction screen,mounting pad for carburetor or fuel injector, the intake riser andintake pipe connections.

Cooling System. These engines are designed to be cooled by airflow. Baffles are provided to build up a pressure and force theair through the cylinder fins. The air is then exhausted to the atmos-phere.

Induction System. The Avco" Lycoming HIO-360 series engines areequipped with a Bendix type RSA fuel injector. The fuel injectionsystem schedules fuel flow in proportion to air flow and fuel vaporiza-tion takes place at the intake ports.The Bendix RSA type fuel injection system is based on the principleof measuring air flow and using the air flow signal in a stem typeregulator to convert the air force into a fuel force. This fuel force(fuel pressure differential) when appli:ed across the fuel meteringsection (jetting system) makes fuel flow proportional to air flow.Lubrication System. (All models except AIO-360 series.) The fullpressure wet sump lubrication system is actuated by an impeller typepump contained within the accessory housing.

Priming System. Fuel injected engines do not require a priming system.

SP EC I F ICATI ONSH1O-360-C SERIES

FAA Type Certificate 1E10Rated horsepower 205Rated speed, RPM 2900Bore, inches 5.125Stroke, inches 4.375Displacement, cubic inches 361.0Compression ratio 8.7:1Firing order i-3-2-4

25Spark occurs, degrees ETCValve rocker clearance (hydraulic tappets collapsed) 028-.080Propeller drive ratio 1:1Propeller drive rotation (viewed from rear) Clockwise

MM-5-5

POWERPLANT OPERATIONS

F-28A Normal Engine Starting Procedures.a. Mixture control IDLE CUT OFF.b. Fuel valve ON.c. Master switch ON.

d. Throttle--crack slightly.CAUTION: Do not open throttle during starting engine; overspeed

can result.

NOTE: Check for clutch disengagement.e. Mixture FULL RICH.f. Fuel boost ON, check pressure for slight increase 1 to 3 seconds,

then return fuel boost to OFF.

g. Mixture OFF.h. Ignition switch, BOTH.i. Engage starter.j. When engine starts, advance mixture slowly.k. Set engine RPM to 1500 1600 RPM.i. Fuel booster pump ON. Pump must be on at all times in flight.m. Check engine oil pressure, 25 PSI minimum.

CAUTION: Shut down engine if minimum oil pressure is notreached within 30 seconds.

n. Disconnect external power (if used).o. Alternator switch ON.

F-28A Engine Starting Procedures, Hot Condition.Repeat steps a, b, c, d, and e as noted above.f. Turn on fuel boost pump 5 to 6 seconds.

g. Turn booster pump off.h. Mixture control OFF.i. Throttle--FULL OPEN.j. Engage starter 5 to 6 seconds to clear engine.k. Close throttle and crack slightly.i. Magneto switch BOTH.m. Engage starter until engine fires and advance mixture slowly.n. Fuel booster pump ON. Pump must-be on at all .times in flight..NOTE: It is important to follow this procedure on hot starts

so that the prolonged fuel flow in the lines willeliminate the vapor locks and cool the lines for aproper start.

F-28A Rotor Engagement.a. Check collective full down.b. Rudder pedals neutral.c. Set longitudinal and lateral trim to center cyclic.

MM-5-6

d. Check aircraft vicinity for personnel and equipment.e. Set engine to 1400 1500 RPM.

NOTE: Maintain fixed throttle during rotor engagement.f. Slowly engage clutch handle at 1400 1500 engine RPM until

rotor RPM reaches 100 RPM.

g. Close throttle.h. Fully engage clutch when engine/rotor needles are superimposed

(marry).i. Advance throttle to 1800 RPM.

CAUTION: Never apply full power until rotor and engine RPMneedles are superimposed and clutch is fully engaged.

F-28A Engine Warmup and Ground Check.a. Warm engine at 1800 RPM until cylinder head temperature

reaches 2000 F.b. Check engine oil temperatures and pressures to ascertain whether

they are within the green arcs.

NOTE: For faster oil warmup in c~ld weather, 2300 RPM maybe used after cylinder temperature has reached 2000 F.

c. Increase engine RPM to 2750 to 2900 RPM and check for RPMdrop on left and right magnetos. 100 RPM is permissible oneither magneto.

NOTE: No engine roughness should be apparent when operatingon either left or right magneto.

d. Check ammeter charging indication.e. Gently move cyclic, observe rotor tip path plane for control

response.f. Close throttle, observe engine and rotor needles for separation.NOTE: Needle separation indicates proper operation of over-

running clutch.

g. Check following before take-off:1. Check all instruments for proper indication.2. Seat belts and doors latched.3. Fuel booster pump ON. Pump must be on at all times in flight.4. Mixture FULL RICH.5. Fuel pressure warning-lgreen indication.6. Set collective and throttle friction.

F-28A Engine Cooling and Shut Down Procedure.a. Stabilize temperatures at 1800 RPM until cylinder temperatures

drop to 3500 F.b. Cyclic trim, neutral.c. Tighten collective friction.

MM-5-7

d. Set engine FULL IDLE.e. Disengage clutch.

CAUTION; Do not disengage clutch unless engine is at FULL IDLE;engine overspeed may result.

f. Fuel boost pump OFF.g. Mixture IDLE CUT OFF.h. Magneto switch OFF.i. Alternator switch OFF.j. Master switch OFF.k. All switches OFF.I. Fuel valve CLOSED.

OPERATING LIMITATIONS

Powerplant Limitations:

Engine: Lycoming ModelHIO-360-C1B

Fuel: 100/130 minimum gradeOil Viscosity: Above 600 F SAE 50

30-900 F SAE 400-700 F SAE 30Below 10" F SAE 20

Horsepower: 205 HP all operations2900 RPM

Operating Engine RPM: 2900 maximum2750 minimum

Engine Idling RPM: 1400 minimum (clutch disengaged)Manifold Pressure: Full throttle, sea level engineOil Temperature: 2450 F maximum

Oil Pressure: 60-90 PSI, normal operation25 PSI, idling minimum100 PSI, starting-warmup

Transmission Oil Temperature: 2200 F maximum

Cylinder Head Temperature: 4750 F maximum

Rotor--Flight Limitations (Power Off):Maximum: 385 RPM

Minimum: 313 RPM

MM-e-e

Instrument Markings:Rotor Tachometer Red Line 385 RPM

Red Line 313 RPMGreen Are 313-385 RPM

Engine Tachometer Red Line 2750 RPMRed Line 2900 RPM

Green Are 2750-2900 RPM

Airspeed Indicator Red Line 112 MPH

Oil Temperature Red Line 2450 FGreen Are 1200-2450 FYellow Are 600-1200 F

Oil Pressure Red Line 100 PSIYellow Are 90-100 PSIGreen Are 60-90 PSIYellow Are 25-60 PSIRed Line 25 PSI

Cylinder Head Red Line 4750 FTemperatures Green Are 2000-4750 F

Transmission Red Line 2200 FOil Temperature Green Are 00-2200 F

FUEL INJECTION SYSTEM

Description. All RSA type fuel injection systems are based on theprinciple of measuring engine air consumption by use of a venturitube and using the airflow forces to control fuel flow to the engine.Fuel distribution to the individual cylinders is obtained by the useof a fuel flow divider and air bleed nozzles.

It is suggested that all adjustments and overhaul to the RSA-5 FuelInjection System be performed with the use of the Operation andService Manual, Form 15-3388, published by the Bendix Corporation.Field Adjustments.Idle Speed and Mixture Adjustment.a. Check magnetos in accordance with instructions furnished in the

aircraft operational manual. If the "mag-drop" is not morethan 100 RPM Max., proceed with idle adjustment.

b. Close the throttle to idle (approximately 1400 1500 RPM).If the RPM changes appreciably after making idle mixtureadjustment during the succeeding steps, readjust the idle speedto the desired RPM.

c. When the idling speed has been stabilized, move the cockpitmixture control lever with a smooth, steady pull, into the IDLE

MM-58

instrument Markings:Rotor Tachometer Red Line 385 RPM

Red Line 313 RPMGreen Are 313-385 RPM

Engine Tachometer Red Line 2750 RPMRed Line 2900 RPM

Green Are 2750-2900 RPM

Airspeed indicator Red Line 112 MPH

Oil Temperature Red Line 2450 FGreen Are 1200-2450 FYellow Are 600-1200 F

Oil Pressure Red Line 100 PSIYellow Are 90-100 PSIGreen Are 60-90 PSIYellow Are 25-60 PSIRed Line 25 PSI

Cylinder Head Red Line 4750 FTemperatures Green Are 2000-4750 F

Transm ission Red Line 2200 FOii Temperature Green Are 00-2200 F

FUEL INJECTION SYSTEM

Description. All RSA type fuel injection systems are based on theprinciple of measuring engine air consumption by use of a venturitube and using the airflow forces to control fuel flow to the engine.Fuel distribution to the individual cylinders is obtained by the useof a fuel flow divider and air bleed nettles.

It is suggested that all adjustments and overhaul to the RSA-S FuelInjection System be performed with the use of the Operation andService Manual, Form 15-3388, published by the Bendix Corporation.Field Adjustments.Idle Speed and Mixture Adjustment.a. Check magnetos in accordance with instructions furnished in the

aircraft operational manual. If the "mag-drop" is not morethan 100 RPM Max., proceed with idle adjustment.

b. Close the throttle to idle (approximately 1400 1500 RPM).If the RPM changes appreciably after making idle mixtureadjustment during the succeeding steps, readjust the idle speedto the desired RPM.

c. When the idling speed has been stabilized, move the cockpitmixture control lever with a smooth, steady pull, into the IDLE

Pk~e

MM-5-9

CUT-OFF position and observe the tachometer for any changeduring the leaning out process. Caution must be exercised toreturn the mixture control to the FULL-RICH position beforethe RPM can drop to a point where the engine cuts out. Anincrease in RPM while leaning out indicates the idle mixture ison the rich side of best power. An immediate decrease in RPM(if not preceded by a momentary increase) indicates that the idlemixture is on the lean side of best power.

d. The desired idle setting is a compromise between one that isrich enough to provide a satisfactory acceleration under allconditions and lean enough to prevent spark plug fouling orrough operation. A rise of 25-50 RPM will usually satisfy bothof these conditions.

e. If Step B indicates that the idle adjustment is too rich or toolean, turn the idle mixture adjustment one or two notches in thedirection required for correction, and check this new positionby repeating Step B. Make additional adjustments as necessary.

f. Each time an adjustment is changed, clear the engine by runningit up to approximately 2000 RPM before making mixture check.

g. The actual idle mixture adjustment is made by the lengthening(richening) or shortening (leaning) of the linkage between thethrottle lever and idle valve lever. The center screw assemblyhas right hand threads on both ends but one end has a No. 10-24thread and the other end has a No. 10-32 thread. For easyreference, consider only the coarse thread end. When it isturned out of its block, the linkage becomes longer and a richermixture is provided. When it is turned into its block, the linkagebecomes longer and a richer mixture is provided. When it isturned into its block, the linkage is shortened and a leanermixture is provided.

h. A major adjustment is available for use when the center screwbottoms out on either of the blocks. If the idle adjustment isalmost satisfactory, measure the distance between the twoblocks. Disconnect the sprilg from the most accessible linkagepin and remove the pin. Turn the block and adjustment screwuntil the adjusting wheel is centered and the distance betweenblocks is as previously measured. There is now additionaladjustment range and the reference point is retained.

i. Make the final idle speed adjustment to obtain the desiredidling RPM with closed throttle.

j. If the setting does not remain stable, check the idle linkage;any looseness in this linkage will cause erratic idling. In allcases, allowance should be made for the effect of weatherconditions upon idling adjustment.

k. Idle speed and mixture adjustments made according to thismethod should require very little further attention except forextreme variations in temperature and altitude.

MM-5-10

1 Fuel inletIdle speedadjustment and strainerMetered

a fuel outlet

I