ATPINDEX

COPYRIGHT 2008

COPYRIGHT IS NOT CLAIMED AS TO ANY PART OF AN ORIGINAL WORKPREPARED BY A UNITED STATES GOVERNMENT OFFICER OR EMPLOYEE ASPART OF THAT PERSONS OFFICIAL DUTIES OR BY ANY OTHER THIRD PARTY

OFFICER OR EMPLOYEE AS PART OF THAT PERSONS DUTIES.

"ATP" is a registered trademark of Aircraft Technical Publishers. All originalauthorship of ATP is protected under U.S. and foreign copyrights and is subject

to written license agreements between ATP and its Subscribers.

ALL RIGHTS RESERVED. NO PART OF THIS PUBLICATION MAY BEREPRODUCED, STORED IN A RETRIEVAL SYSTEM, OR TRANSMITTED IN ANY

FORM BY ANY MEANS, ELECTRONIC, MECHANICAL, PHOTOCOPYING, RECORDING OR OTHERWISE, WITHOUT PRIOR WRITTEN PERMISSION OF THE

PUBLISHER.

Aircraft Technical Publishers Customer Service101 South Hill Drive 6AM-5PM PST M-FBrisbane. CA 94005 (800)227-4610

ATP Grid Index to Manufacturers Publications:

Enstrom HelicopterModel F28CFlight Manual

Section

General Information

Title PageList of Chapters (Table of Contents)

Record of RevisionsRecord of Temporary Revisions

Section 1 General

Section 2 Limitations FAA Aproved

Section 3 Normal Procedures FAA Approved

Section 4 Emergency 6 Malfunction Procedures FAA Approved

Section 5 Performance FAA Approved

Section 6 Weight and Balance

Section 7 Aircraft and System Description

Section 8 Aircraft Handling, Servicing and Maintenance

Section 9 Operational Information

Section 10 SupplementsWet/Dry Dispersal System Supplement No. 1

Float Landing Gear Supplement No. 2External Loads Supplement No. 3

02/22/2008 Copyright Aircraft Technical Publishers Page 1 of 2EN 0140 FM

Section Topic

Snowshoe Supplement No. 4

End of Index

02/22/2008 Copyright Aircraft Technical Publishers Page 2 of 2EN 0140 FM i

NIFGI

INTRO

FLIG~MTMANUAL

EN~ r-ROAA

THIS IS THE F28C

Manufactured by The Enstrom Helicopter Corporation,Menominee, Michigan. This manual pertains to Model F28Chelicopters S.N. 418 and up or as modified in accordance withEnstrom Drawing 28-100005.

Ownership of the Turbocharged F28C Helicopter will provideyou with a smooth, distinctive, and comfortable mode of flightgeared to the concept of modern transportation. For business orpleasure, the field of operations is practically unlimited, as point-to-point travel can be accomplished from either prepared orunprepared areas. The distinctive appearance of the F28C issymbolic of prestige and its high performance capabilities.Under the graceful lines of the F28C is a ruggedly constructedhelicopter designed for easy servicing, minimum maintenance,dependability and economical operation.

Copyright 1976 Enstrom Corporation, Menominee, Michigan, U.S.A.

ORIGINALAs Received By

ATP

Reprint: 1994 Report No. 28-P~C-(117

RECORD OF REVISIONS

~$aMFG REV

NO DESCRIPTION ISSUE DATE ATP REV DATEI INSERTED BY

Original Issue 5/22/98 3/5/08 SHY

2/22/2008

RECORD OF TEMPORARY REVISIONS

TEMP ATP REV INSERT DATE REV REMOVEREV NO DESCRIPTION ISSUE DATE DATE BY REMOVED INCOR BY

2/22/2008

SECTION GEMERALintroduction FM-1-1Principle Dimensions of the Enstrom F-28C FM-1-2Specifications FM-1-3

SECTION 2 LIMlfATIONS FAA APPROVED

Title Page-Approved Section FM-2-1Log of Pages and Revisions FM-2-2Log of Supplements FM-2-3Power Plant Limitations FM-2-4Rotor- Flight Limitations -PowerOff FM-2-5Rotor- Flight Limitations- PowerOn FM-2-5Airspeed Limitations FM-2-5Altitude Limitations FM-2-5Weight Limitations FM-2-5Centerof Gravity Limitations FM-2-5Instrument Markings FM-2-6Type of Operation FM-2-6Placards FM-2-7

SECTION 3 NORN(AL PROCEDU RES FAAAPPROVED

Normal Engine Starting Procedure FM-3-1Hot Day Engine Cooling and Shutdown Procedure FM-3-2Hot Engine Restarting Procedure FM-3-3Rotor Engagement FM-3-4Engine Warm-up and Ground Check FM-3-4Flight Information FM-3-5cruise FM-3-5Special instructions for Leaning In Flight FM-3-6Running Landing i FM-3-7Prelanding Checks FM-3-7Normal Engine Cooling and Shutddwn Procedure FM-3-7EGT Leaning Procedure- Cruise Condition FM-3-8

SECTION 4 EM ERGENCY MALFUNCTIONPROCEDURES FAA APPROVED

Engine Failure FM-e?Lighting Failure FM-4-1Fire FM-4-1Fire on Ground FM-4-1Fire In Flight FM-4-2Tail Rotor (Anti-Torque) System Failure FM-4-2Tail Rotor Drive System Failure FM-4-2

Revised: May 22, 1998 Report No. 28-AC-017

Tail Rotor System Failure FM-4-3Pitch Link Failure (One Tail Rotor Blade) FM-d3Failure of Left Pedal Controls FM-e4Failure of Right Pedal Controls FM-4-4Landing in Water(Ditching) FM-d5Ditching With Power FMd-5Ditching Without Power FM-dSAltematorFailure FMd-5Main RotorGearbox FM-4-6Electrical Fuel Boost Pump FM-eeLow Engine Oil Pressure FMd-6Turbocharger Failure FM-4-6Abnormal Vibrations FMd-7

SECTION 5 1 PERFORMANCE I FAA APPROVED

V,, (Never Exceed Speed) vs. Density Altitude FM-5-1Airspeed Calibration FM-52HoverCeiling In Ground Effect FM-5-3HeightVelocity Diagram FM-5-4Effect of Off-Loading on Choice of H-V Envelope FM-5-5DensityAltitude Chart FM-56Rate ofClimbwith DensityAltitude FM-5-7

SECTION 6 WEIGHT AND BALANCE

Information FM-6-IWeight and Balance FM-6-1Toois and Equipment......:

........._

FM-e-2Detaiedl Procedure for Weighing F-28C Series HelicopterFM-6-2Loading Information FM-6-6Center of Gravity Envelopes FM-6-7

Longitudinal CG FM-6-7Lateral Offset Moment FM-6-7

Equipment List FM-6-8Basic Weight and Balance Record (Form F-165) FM-69Weight and Balance Report (Forn F-166) FM-6-10Aircraft Actual Weight Report (Form F-167) FM-6-11Aircraft Weight and C.G. Calculation (Form F-168) FM-6-12S ECTI O N 7 Al RC RAFT AND SYSTEMDESCRIPTION

InteriorArrangement FM-7-1Air induction System FM-7-1Power Plant FM-7-1Oil System FM-7-2

Oil System Indicators Oil Temperature andPressure Gauges FM-7-2

Revised: May 22, 1998 Report No. 2&AC-017

Engine Controls FM-7-2Throttle FM-7-2Mixture Control FM-7-2

FM-7-2Magneto SwitchIgnition Safety Switch FM-712Starter Button FM-7-2MasterSwitch FM-7-2

Turt~ocharger FM-7-3Exhaust GasTem9erature System FM-7-3Cabin Heat FM-7-3Clutch Engaging Lever FM-7-3Fuel System FM-7-3

Auxiliary Fuel PumpSwitch FM-7-4Fuel Quantity Indicator FM-7-4Fuel Flow- Fuel Pressure Indicator FM-7-4

Transmission System FM-7-4Main Rotor Transmission Temperature Indicator FM-7dTail RotorTransmission FM-7d

Rotor System FM-7-5Main Rotor FM-7-5Tail Rotor ....~.....FM-7-5RotorTachometer FM-7-5

Flight Controls FM-7-5Cyclic Control FM-7-5Stabilizer FM-7-5Collective Pitch Control FM-7-5Directional Control Pedals FM-7-5

Flight Instruments FM-7-6Airspeed Indicator FM-7-6Altimeter FM-7-6Compass FM-7-6FreeAirTemperature Indicator FM-7-6

Electrical Power Supply System FM-7-6Direct Current Power System FM-7-6Keyto Instrument Panel FM-7-7Electrical Power Panel FM-7-8

Lighting Equipment FM-7-8Position Lights FM-7-8Anti-Collision Lights FM-7-8Landing Lights FM-7-8

Ground Handling Wheels FM-7-8Baggage Compartment FM-7-9

SECTION 8 AIRCRAFT HANDLING, SERVICINGAND MA1NTENANCEGround Handling FM-8-1Mooring FM-&I

Revised: May 22, iSSB Report No. 28-AC-017

Transporting FM-&~Storage FM-&1Hoisting FM-&2Jacking FM-8-2Exterior Paint FM-8-2Windows and Doors FM-&2Upholstery and Carpets FM-&2Landing GearShock Struts FM-&2AirCleanerorFilter FM-8-3Lights ....,..................,.............FM-&3Battery FM-&3Dampers- Main Rotor FM-&3Transmission Main Rotor FM-&3Transmission- Tail Rotor FM-&3Lubrication FM-&3Excessive Grease FM-&4Main Rotorand Tail Rotor Blades FM-&4Fuel FM-&4Oil FM-8-4Cooling System FM-8-5Required FAA Forms FM-&5Preflight inspection FM-8-6

Exterior FM-8-6interior FM-8-7

Exterior tnspedion Diagram FM-&9

SECTION 9 OPERATIONAL INFORMATION

Solo Flight FM-9-1Taxiing FM-9-1Takeoff FM-9-1Normal Takeoff to Hover FM-9-1Normal Takeoff from Hover FM-9-2Maximum PowerTakeoff FM-9-2Maximum PowerTakeofffrom ConfinedArea FM-9-3Crosswlnd Takeoff FM-9-3Normal Approach for Landing FM-9-4Steep Approach FM-9dLanding Landing Site Evaluation FM-9-4Wind Direction and Velocity FM-9-5Normal Landing FM-9-5Crosswind Landing FM-9-5Flight Charcteristics- Handling and Stability FM-9-6Maneuvering Flight FM-9-7Hovering Flight FM-9-7Student Training FM-9-7Noise Abatement FM-9-7Leaning with an EGT FM-9-8

Revised: May 22, 1998 Report No. 28-AC-017

Cold WeatherOperation FM-9-8Blade Tape FM-9-9Loss ofrail RotorEffedivenesS FM-9-9Fuel Flowvs. Noule Pressure Chart FM-9-10Average Cruise Performance FM-9-~I

SECTION 10 SUPPLEMENTSWet/Dry Dispersal System Supplement No. 1

Section i-General FM-1(E1-1Section 2 Limitations FM-1CZ-1-1

VNE MPH IAS PlacardSection 3 Normal Procedures

PreflightCheck FM-IO-1-2Section 4 Emergency and Malfunction Procedures

Liquid Jettison FM-lel-2Loss of Power FM-I0-I-2Loss of Tail Rotor FM-IO-1-2VibrationSpreader Malfunction FM-Iel-3

Section 5 PerformanceList of Figures i FM-IO-1-3V,, vs. DensityAltitudeHoverCeiling in Ground Effect FM-le?-5Airspeed Calibration FM-IO-1-6HeightVelodty Diagram FM-lel-7

SectionG-Weightand Balance FM-IO-1-8Section 7 System Description and Installation instructions

Initial Installation FM-10-1-8Wet Dispersal System Installation FM-IO-~-8Wet Dispersal System Removal FM-le~-9Dry Dispersal System Installation FM-?el-9Dry Dispersal System Removal FM-Iel-9Return to Normal Category FM-10-1-9

Float Landing Gear- Supplement No. 2Section i-General FM-1 0-2-1Section 2 Operating Limitations

Type of Operations FM-~e2-1V MPH IAS Placard FM-10-2-1Sed~bEn 3-Mormal ProceduresRotor Engagementon Water FM-~ 0-2-2Flight Information FM-le2-2Running Landing FM-~e2-2Base Altitude Change FM-10-2-2

Section 4 Emergency ProceduresEngine Failure During Flight (Above 80 MPH) FM-10-2-3Engine Failure During Flight (Below 80 MPH) FM-10-2-3

Revised: May22,1998 Report No. 28-AC-017

Section 5 PerformanceDefinition FM-1 0-2-3Rate of Climb FM-10-2-3

t~EVS DensityAltitude Chart FM-10-2-4Airspeed Calibration Chart l"M-l e2-5

Section 6 Weight and BalanceOperational Equipment FM-le2-6Center of Gravity Limit Envelopes FM-le2-6

External Loads Supplement No. 3

Section?- General FM-10-3-1Section 2 Operating Llm~tations

Engine FM-l 0-3-1Airspeed FM-le3-IAltitude FM-10-3-~Weight F=M-IO-3-~Center of Gravity FM-10-3-2Type of Operations FM-10-3-2V,, MPH IAS Placard FM-ie3-2

Section 3 Normal ProceduresPrenight Operation Check FM-ie3-2StaticEledricity Discharge FM-10-3-3Cargo HookOperation FM-ie3-3

Section 4- Emergency Procedures FM-10-3-3Section 5- Performance Data FM-le3-4Section 6 Weight and Balance FM-Ie3-4

Optional Equipment FM-1 0-3-4Snowshoe Supplement No. 4

Section i-General FM-10-4-ISection 2 Operating Limitations

Airspeed FM-~O-elWeight FM-?e61Center of Gravity FM-10-4-1

Section 6-Weight and Balance FM-le4-1Optional Equipment FM-4O-el

Revised: May 22, 1998 Report No. 28-AC-017

FM-1-3

ENSTROM F28 C

SPECIFICATIONSPower Plant

Type Lycoming OpposedDesignation .HIO-360-E1ADCylinders .........,,,.4Normal Power............ .205 HPNormal RPM .....2900 RPMSpecific Fuel Consumption(Full Rich) .........,,,,69 Ibs. hp/hr.Weight .322 Ibs.Oil ...10 qts. 16 Ibs.Performance

Maximum SpeedVNE PowerOn .,..........112 MPHto3000ft. Above

3000 ft. see FM-5-1

PowerOff ................Due to high rates of descent athigh forward speeds, sustainedautorotation speed is limited to85 MPH to 8200 ft. Above 8200ft., see FM-5-1.

Best Rate of Climb .........57 MPH IAS at sea level;above sea level see FM-5-7

Normal Fuel Capacity .......40 U.S. gal. at 240 Ibs.Rate of Climb at Sea Level ...1125 FPM

Hovering Ceiling IGE .....8800 ft.Standard Day 23501b. G.W.Service Ceiling ............Above 16,000 ft.Operating RPMEngine .2750 2900Tail Rotor .2504 (at 2900 engine RPM)Main Rotor ...............350 (at 2900 engine RPM)Main Rotor Autorotation Range 332 385

*Maximum FAA approved operating ceiling presently limited to 12,000 ft.

Report No. 28-AC-017

FM-1-4

ENSTROM F28C

Ratios

Lower to upper pulley .................1: 157Main Rotor Gear Box............... ...1:7.154Tail Rotor Gear Box.....,..............1 :tEngine to main rotor 8.277Dimensions

Width (overall) ............................28 2"Rotor diameter............................32Height (overall) 9Length (overall) ..........................27 8"Cabin width at seat.....................58"Tread-Landing Gear 7 4"Rotor SystemNumber of blades,Main rotor ................3Cord-main rotor blade ................9 .5"Disk area, main rotor 804 so. ft.Main rotor RPM

...........,..............350

Tail rotor diameter ...4.67"Number of blades, tail rotor.....,.2Chord, tail rotor blade.................4.4"

WeightDesigned gross weight ...............2350 Ibs.Empty weight (approx.) ..............1495 Ibs.Useful load

.................................855Ibs.

C.G. travel..................................92"

to 94.6" at 2350 Ibs.92" to 100" at 2000 Ibs.

Report No. 28-AC-017

FM-1-1

ENSTROM F28C

SECTION 1 GENERAL

INTRODUCTION

This manual meets all FAA requirements for approved data andthis data is so designated. It also contains supplemental datasupplied by the Enstrom Helicopter Corporation.In addition to this manual, the Enstrom Helicopter Corporationalso has available for your helicopter a Maintenance Manual anda Parts Catalog. Both of these can be obtained from yourEnstrom dealer or from the factory.Periodic revisions are made to these manuals to incorporatechanges and additions. Service information is also issued toowners of record in the form of:

Service information letters (informative and advisory)Service directive bulletin (mandatory)

Report No. 28-AC-017

ZO

m$Z r.V)~ m336~ (28.0~) Z

V)I, rbxl 3-1

--219~ (18.25) Orn oRnolus

~z-n ol

i 7 I MAX. FYV). C. G.156" (4.7)DIA.

O v,23.. STATIC O

tos (9.0I -n

-I~D-O I;5 72.. (6.0.1 M1N. DROOPO 73.5" (6.125) 93.75~

~(7.8131 m

(6.55.) 1(4.0..-~1 I~ico I1 78.65~--------96 (8.0)~337" (28.

351.6~ (29.3)88" (7.333)

i i

P~Aircraft Technical Publishers L~ Aircraft Technical Publishers

FM-2-1efJSTROMf~

2 LIMITAT)ONS

ENSTRC)M MODEL F=28COPTE)I

:::i:i::

I,::

ii"::~i-::

a~:::.:::::.:::j::

i::5;:

(3R\G\NALAs Received 8~

A7C) Z~:0

i:l"l~"i:-i

L\ i:.

yge Certi~icale No. H1

egiS~ratian No.

pproved by

or Cniel, Engineering and Manufac~uring BranchiiSht Standardsreal Lakes Regioneberal Aviation Admlr\~stralion

pril 20, 1 Q78

NOTE: Seclions 2, 3, ct. and 5 are FAA approved. Section 10includes supplements to the type certificate whictl sreTAA approved if so designoteb.

~OTE: This manual pe~ains to Model F28C helicopten SM 1418and up or as modified in accordance with Enstromarswing 2&~00Q05.

FAA Approval: April 20. 1978 Report No. 2BAGO11

Aircraft Technical Publishers

FM-2-2ENSTROM F28C

LOG OF PAGES AND RF~VISIONS

Rev.No. Pages Description Date F.A.A. Approved

FM Revised1 1051 Exterrurl Coed

FM Suppleme~t

1032FM 4C2SP10-33 ca

Revised FloatFH Supplement toO-2-1IAdd Restricted i.d,l$ PL~P2 thru Catagory~-2-6 Envelope

ed Supplameat5, 6, 53

FM Added placard

3-42-7 6 operational3-3 inforrnation.3-5FM2-2 Added operation

2-4 instructions, q4 2-7 infonation ArJC3-3 $53-3 and placards.

thru(7~3, 9-2. 9-33- 6 1

Approved for ManagerChicago Aircraft Certification OfficeCentral RegionFederal Aviation Administration

NOTE: All revisi~ns are indicated by a blackverticalline. I

FAA Approval: April 20, 1978Revised: May 22, 1998 Report No. 2&AC-017

FM-2-2.1ENSTROM F28C

LOG OF PAGES AND REVISIONS

Rev.No. Pages Desci~ptiom Dots F.A.A. Apgrov~Ld

~v ded 6lade rapeFM- 3- ded Step

5 n~-3-4)3inor RevisionFM-8- ded Blade Tape

9- Bfl Added Abnormal

6 VibrationsFH4- Added page

w Revised PageNumbering B

FM-2-2.1) FAA Approval 6XFM-d-5 IRevlsed EmergencyFMd~ IProcedure and

FMd-7 IText, Added PageFM-8-9 ICorrected HeaderFM-0-0 IAdded Text

Approved for ManagerChicago Aircraft :%ertification OfficeCentral RegionFederal Aviation Administration

NOTE: All revisions are indicsled by a blade vertlcalline. I

FAA Approval: April20, 1978Revised: May 22, 1998 Report No. 2&AC-017

FM-2-3

ENsTRoM F28C

LOG OF SUPPLEMENTS

Supp.No. Pages Description Date F.A.A. Approved

WetlDry 55-781 8 Dispersal System

FLOATLANDING GEAR2 6

External Loads3 2 Supplement 728-78 i,,4 1 supplementSnowshoe

*Approved for Chief, Engineering and Manufacturing BranchFlight Standards DivisionGreat Lakes RegionFederal Aviation Administration

NOTE: All revisions are indicated by a black vertical line. I

Report No. 28-AC-017

FM-2-4

ENSTROM F28C

OPERATING LIMITATIONS

NOTE: Mandatory compliance with the Limitations, Section 2, isrequired by law.

FAA OPERATING LIMITATIONSPOWER PLANT LIMITATIONS

Engine ...........Lycoming Model HIO-360E1ADwith Rajay 301 E-10-2Turbocharger

Fuel ................1 00/130 minimum gradeOil Viscosity ......................Above 60 "F.............................SAE-50

30-90 "F...................................SAE-400-70 "F.....................................SAE-30Below 10"F

..............................SAE20

Approved Lubricants:50-hour break in period, MIL-L.-60828Ashless Dispersant, MIL-L-22851

Engine Limits 2900 rpm, 36.5 in. MP (205 HP)Operating Engine RPM.....2,900 maximum..........................................2,750

minimum

Engine Idling RPM ............1,500 minimum (clutch disengaged)Manifold Pressure .........,..36.5 in. Hg, Sea Level to 12,000 ft.EGT....; ...........1,650"8 maximumbit Temperature................245 "FOil Pressure ...60-90 psi, normal operation..........................................25 psi, idling minimum

....100 psi, starting warmupTransmission Oil Temp.....220 of maximumCylinder Head Temp.........475 "F maximumFuel Mixture Setting..........Engine may be leaned at 28 in. MP or

below to 1650 "F on rich side of peak.Never exceed 1650 "F EGT. Mixturemust be enriched for landings andtakeoffs requiring more then 28 in.MP. Do not exceed 1550-1575 "F I LEGT above 28 in. MP. Mixture mustbe leaned to at least 130 pph at 36.5in. MAP for all flight conditions excepthover. If richer mixture is required tomaintain EGT levels below 1650 "F,practice autorotations are prohibited.

FAA Approval: April 20, 1978Revised: Aug. 29, 1985 Report No. 28-AC-017

FM2-5

SNSTROM,FZC

ROTOR FLIGHT LIMITATIONS (POWER OFF)Maximum:

........................,...385 rpmMinimum

.........................,,...332 rpmROTOR FLIGHT LIMITATIONS (POWERON)Minimum:.......,,..............,.....332 rpm:Maximum

,.................,..........350 normal operatingAIRSPEED LIMITATIONS

Never exceed speed: VNE: 112 mph IAS SL to 3000 ftHD.For variations greater than 3000 ft.,see FM-5-1.

ALTITUDE LIMITATIONS

Maximum operating: ............12,000 ft. density altitude.NOTE: (rnformation only) Takeoffs and landings at 2350 Ibs,

gross weight were demonstrated during FAA typeinspection tests up to 7,000 ft. density altitude.Operators should use appropriate caution above 7,000ft. density altitude and limit gross weight as required toinsure safe takeoffs and landings.

WEIGHT LIMITATIONS

Maximum approved weight: 2350 Ibs.CENTER OF GRA\IITY LIMITATIONS

Forward:.,....,.......,.,.......,......2350

Ibs, 92,0 in, stationRearward:

.......,....................2350Ibs. 94.6 in, station

2200 I:bs. 96.7 in. station2000 Ibs. 100,0 in, station

Lateral offset moment: .........2350 Ibs. -3250, +3700 in Ibs.below 2015 Ibs. See FM-6-7.

This helicopter is to be loaded in accordance with SECTION 6,LOADING INFORMATION.

NOTE: Loncritudinal ..........Station 0 (Datum) is located 100inches forward centerline of main rotor hub.

Lateral...............................,.Station

0 (Datum) is aircraft centerline, lateral moment arms are positive right, negative left(looking forward)

FAA Approval: April 20, t 978Revised: Aug, 20, 1005 Report No. 20-AC-017

FM-2-6

ENSTROM F28C

INSTRUMENT MARKINGS

Rotor Red Line ...............385 RPMTachometer .Red Line ...............332 RPM

Green Are........................332-385

RPM

Engine ,..........................Red~ Line........~.................,..,..2750 RPMTachometer ...................Red Line.,...,.,,............,......,...2900 RPM

Green Are....................2750-2900

RPM

Airspeed ..~.....................Blue Line.......,,..,..(Power Off) 85 MPHIndicator.........................Red Line ,,,,,,,,.,,(Power On) 112 MPHManifold Pressure..........Red Line

.........,.,.........,......~..36.5in, Hg

Oil Temperature .............Red Line .245 "FGreen Arc..,...........~ ..,,......,...1 20-245 "FYellow Are ..,,,,,.,,,60-120 "F

Oil Pressure Red Line t 00 PSIGreen Are ..........60-100 PSIYellow Are

............,.................25-60PSI

Red Line 25 PSI

EGT ,,,,,,,,,,,,Red Line

Cylinder Head ................Red Line ...475 "FTemperatures ,,,,,,,,,,,,,G reen Are ,,,,,,,,,,200-475 "F

Transmission ...........,.....Red Line......~..........,...............,,...220

"F

Temperature ..................G reen Are ..............0-220 "F

TYPE OF OPERATION

The helicopter is approved for operation under DAY NIGHTVFR NON-ICING conditions,

Night operation authorized under visual contact flight conditions,Orientation must be maintained by ground light or adequatecelestial illumination,

Instrument flight prohibited,No aerobatic maneuvers permitted,Cross wind and downwind: When hovering or landing, ade-quate flight control has been demonstrated in winds to 20 mphto 5000 ft, density altitude at 2350 Ibs, gross weight, Operatorsshould use appropriate caution above 5000 ft. density altitude inhigh wind conditions and limit gross weight as required to insuresafe takeoffs and landings,Operation with doors removed is approved,

FAA Approval: April 20, 1978 Report No, 28-AC-017

FM-27

ENSTROM F28C

PLACARDS:

"THIS HELICOPTER MUST BE OPERATED IN COMPLIANCEWITH THE OPERATING LIMITATIONS SPECIFIED IN THE FAAAPPROVED ROTORCRAFT FLIGHT MANUAL,

AIRSPEED LIMITATIONSNEVER EXCEED SPEEDS MILES PER HOUR IAS

PRESSURE OUTSIDE AIR TEMPERATURE "Fi;~--

ALTITUDE -20 0 20 40 60 80 100

SEA LEVEL 112 112 112 112 112 112 1122000 112 112 112 112 112 109 1044000 112 112 112 110 105 100 916000 112 111 106 101 91 82 738000 107 102 91 82 73 64 5510000 94 83 73 64 5412000 76 65 55

"NO SMOKING" (This placard not required when an approvedashtray is installed.)

"THIS HELICOPTER IS APPROVED FOR OPERATION UNDERDAY NIGHT VFR NON-ICING CONDITIONS ONLY,

"MAXIMUM WEIGHT IN THIS COMPARTMENT 60 LBS.OBSERVE CG AND GROSS W:EIGHT LIMITATIONS.

"COLLECTIVE FRICTION TO BE USED FOR GROUND OPER-ATION ONLY" (This placard to be placed adjacent to the collec-tive friction device.)

"LEAN TO 130 PPH AT 36.5 IN. MAP IN FLIGHT SEEREVISED RFM." (This placard to be placed in view of the pilot.)

"STOW FLAT ON FLOOR BEFORE FLIGHT" (This placard to beplaced on clutch handle).

FAA Approval: April 20, 1978Rovlffod: Aug, 28, 1905 Report No, 20AC017

FM-2-8 8 2-8-UK

ENSTROM F28C

FOR NICKELICADMIUM BATTERY INSTALLATION ONLY

BATTERY TEMPERATURE ALERT

120 "F MONITOR BATTERY TEMPERATURE (AMBER LIGHT)130 "F TURN OFF ALTERNATOR SW.

REDUCE ELECTRICAL LOAD, TURN ALT, SW, ON IF AMBER LT.GOES OUT IN FLIGHT.

150 "F TURN OFF MASTER SWITCH.

(RED ARC) LAND AS SOON AS PRACTICAL. INSP. BATTERYPER MANUF, INSTR. BEFORE FURTHER FLIGHT,

EACH 250 HR, INTERVALS PERFORM FUNCTIONALTESTS PER K.S. AVIONICS INSTRUCTIONS.

PLACARDS (Continued)

PULL FOR IDLE CUT-OFFTURN TO LEAN

FAA Approval: April 20, 1978Revised: Feb, 17, 1989 Report No. 28-AC-017

FM3-1

ENSTROM F28C

SECTION 3 NORMAL PROCEDURES

NORMAL ENGINE STARTING PROCEDURES

1, Seat belts fastened and doors latched.

2. Fuel valve pushed in to turn on.3. Collective full down and secured with the friction knob.

4. Heater as desired tin forOFF).5. Cyclic stick cannon plugs secure.6. Rotor clutch disengaged.

CAUTION: Although starting the helicopter with the rotorclutch engaged will not damage the rotor sys-tem, it will severely overload the starter motor.

7. Check compass full of fluid, no bubbles, and with a correc-tion card.

8, Altimeter set to field elevation.

9. Radio(s) off.10. All switches off.

11, Master switch and alternator on (alternator off if using anAPU start). Ignition switch on.

12. Throttle full open for engine prime only.13. Mixture full rich.

14. Fuel boost pump on until the fuel pressure gauge shows a

rise, then boost pump off.

15. Mixture idle cut off; throttle closed then cracked openapproximately 1/16", mags on both; depress starter, whenengine starts mixture in.

16. Fuel boost leave off during first cold start and ground runto insure proper operation of engine driven fuel pump.

17. Check engine oil pressure is off the zero line within 30 sec-ends..

18. Check amp meter gauge indicates a charge.

19. If APU start disconnect APU cable. Then alternator switch

on check for a charge indication on the amp meter.

20. Idle engine at 1450 to 1500 rpm.

I-M-3-2

ENSTRoM F28C

21. When oil pressure is 25 psi or above clutch may besl,yayud.CAUTION: On rare occasion the engine may backfire

through the induction system, during a start pro-cedure. The backfire will not cause damage tothe induction system but it could cause theinduction hose between the air filter and the fuelinjection servo unit to be disconnected due tothe backfire. It is recommended that should abackfire occur during engine starting, a visualinspection be accomplished by the pilot ormechanic to assure that the hose is securely inplace before takeoff.

22. Note engine idle rpm (with boost off) and turn fuel boost on,Any difference in rpm noted indicates leaky idle mixtureplates (refer to Enstrom Service Letter No, 0069), Slowlylean engine with mixture control short of cutoff position. Anincrease of 50 rpm indicates idle mixture improperly set(refer to Enstrom Service Letter No, 0069).

HOT DAY ENGINE COOLING ANDSHUTDOWN PROCEDURE

The following procedures are recommended for hot weatheroperations, operations at high altitudes and when hot enginerestarts are anticipated. This shutdown procedure empties thefuel lines within the hot engine compartment preventing fuelvaporization within the lines. A successful engine start shouldresult when cool fuel is introduced into the lines immediatelyprior to engine cranking using the hot engine restarting proce-dure. Operations at high density altitudes may require a mixturecontrol adjustment to ensure proper engine idle.

1, Collective pitch control full down and friction on,2. Throttle idle position.3. Fuel boost pump on.

4, Clutch disengaged, engine at full idle position,5. Cyclic control centered with trim control.6. Fuel shut-off valve closed tout). Residual fuel in the lines

will provide sufficient time at idle to ensure proper enginecool-down (two minutes or cylinder head temperature lessthan 300 "F.).

FAA Approval: April 20, 1978Revised: Aug, 29, 1985 Report No. 28-AC-017

FM3-3

ENSTROM F28C

NOTE: The red fuel system pressure low light will illuminatesoon after the fuel shut-off valve is closed. This is a normalindication with the fuel shut-off valve closed even though theboost pump is still operating.

7. When engine stops boost pump OFF.8. Radios OFF.9. Magnetos OFF.

10. Lights OFF.11. All switches OFF.12. Mixture idle cut OFF.13. Throttle closed.14. Master switch OFF.

HOT ENGINE RESTARTING PROCEDURE

1. Seat belts fastened and doors latched.2. Collective full down and secured with friction.3. Rotor clutch disengaged.4. Radios OFF.5. All switches OFF6. Master switch and alternator ON. (Alternator OFF if using an

APU start).7. Fuel valve on (pushed in).

NOTE: Initiate start as soon as possible after opening fuelshut off valve.

8. Throttle full open (for engine prime only).9. Mixture control in:full rich position.

10. Fuel boost pump on until fuel flow gauge shows a rise(approximately 5-8 seconds), then boost pump OFF.

II. Return throttle to idle position and then crack open slightly,approximately 1/16".

12. Mixture to idle cutoff position.13. Check throttle cracked, ignition switch on, mags on BOTH

position.14. Depress starter, when engine fires, advance mixture control

to full rich position and turn boost pump on immediately topreclude vapor lock.

15. Follow steps 17 through 21 of "Normal Engine StartingProcedure".

FAA Approval: April 20, 1978Revised: Feb. 17, 1989 Report No. 28AC-017

FM34

ENSTROM F28C

ROTOR ENGAGEMENT1. Check collective pitch full down. Friction ON.

CAUTION: Collective friction to be used for ground opera-tion only.

2. Tail rotor pedal neutral position.3, Center cyclic stick with trim switch. I4. Check aircraft vicinity clear of.personnel and equipment.5. Check engine idle set at 1450 to 1500 RPM, then leave

throttle fixed in this position; do not add more throttle duringengagement.

6. Slowly and smoothly engage clutch handle at 1450 to 1500RPM, allowing the engine RPM to bleed no lower than 1200RPM. When the rotor RPM reaches 100 RPM, fully engageclutch.NOTE: Clutch disengage warning light will go out when

clutch is fully engaged.7. Place clutch handle in stowed position.

ENGINE WARMUP AND GROUND CHECK

1. Advance throttle to 1800 RPM and wait for cylinder headtemperature to reach low green or 200 "F.

2, After reaching 200 "F. cylinder headtemperature, slowlyadvance throttle to 2300 RPM until oil temperature readslow yellow or 80 "F.

3. Check the magnetos using the following procedure:a) At flat collective pitch and 2900 rpm allow the EGT to sta-

bilize, with mixture in full rich position!b) Set the E.G.T. gauge cursor red needle to the stabilized

indicated temperature. (This will be a referenced temper-ature during the mag test).

c) Switch from both mags position to left mag position andnote RPM drop and E.G.T. rise for five seconds. Themaximum allowable RPM drop is 125 RPM. The maxi-mum allowable E.G.T. rise is 100 "F.

d) Return magneto switch to both, allowing E.G.T, and RPMto stabilize and repeat check on the right mag position.

e) The maximum permissible RPM differential between leftand right magnetos is 50 RPM without engine roughness.A differential of greater than 50 RPM and/or a drop in RPM

FAA Approval: April 20, 1978Revised: Feb. 17, 1989 Report No. 28AC-017

FM-3-5

ENSTRoM F28C

greater than 125 RPM could indicate spark plug, sparkplug lead wire, or magneto problems.

f) An E.G.T. rise over 100 "F. during operation on individualmagneto indicates a magneto timing problem.

4. Gently close throttle to spl:it tachometer needles to checkproper operation of over running clutch.

5. Check the following before take-off:a) Check all instruments for proper indication.b) Seat belts and doors latched.c) FuelON.d) Fuel boost ON. (Pump must be on at all times in flight).e) Mixture FULL RICH.f) Fuel pressure warning green indication.g) Clutch warning light push to test red light goes out

when released.

h) Release collective friction.NOTE: Keep hand on collective and maintain down position

when friction lock is disengaged.i) Set throttle friction as desired.

FLIGHT INFORMATION

1. Follow normal helicopter takeoff procedures at 2900 RPM.(See height-velocity informaaionn-pages FM-5-4 and FM-5-5.)Linear interpotations may be used for operation betweensea level and 7000 ft.

2, Best rate of climb speed varies with altitude, i.e., 57 MPH atsea level decreasing to 52 MPH IAS at 7000 ft,, and 49MPH IAS at 12000 ft.

3. Do not exceed 36.5 inches of manifold pressure during thetakeoff maneuveri

CRUISE

Exhaust gas temperature, as shown on the Enstrom E,G,T. indi-cator, should be used as an aid for fuel mixture leaning in cruis-ing flight at 75% power or less, i.e., 28 inches manifold pressureand 2900 RPM. Do not exceed VNE as shown on placard andthe VNE versus altitude curve.

FAA Approval: April 20, 1978Revised: Feb. 17, 1989 Report No. 28-AC-017

FM-3-6

ENSTROM F28C

To obtain a best economy mixture, lean to 1650 "F E,G.I. Too~laiil a best power rriixluro, loan only to 1550 "1-exceed 1650 "F E.G.T. Operation on the lean side of peakE.G.T, is not approved. Also any change in altitude or power willrequire a recheck of the E.G.T. indication,SPECIAL INSTRUCTIONS FOR LEANING IN FLIGHT

1. The mixture must be leaned to at least 130 PPH at 36.5inches MAP. Do not exceed 1650 "F E.G.T.

2. If mixture greater than 130 PPH is required to preventexceeding E.G.T. of 1650 "F, practice autorotation/powerchop are prohibited.

3. With mixture leaned as prescribed in (a) above, practiceautorotation/power reductions are to be performed as fol-lows:

a) Close throttle smoothly all the way to the closed positionand hold on the stop, or:

b) Smoothly split needles and maintain engine RPM at 2000or above.

c) Do not try to maintain throttle at intermediate positionsbetween fully closed and 2000 engine RPM as this maycause inadvertent engine stoppage due to improperidle/mixture settings or faulty fuel servo.

NOTE: Since the F28C is equipped with a full-time tur-bocharger, the turbocharged engine is equippedwith an overboost warning light on the instrumentpanel to warn the pilot of an overboost condition.Transient overboost conditions which may triggerthe warning light may not show as overboost condi-tions on the manifold pressure gauge. The manifoldpressure gauge red line is the determining factor inascertaining the magnitude of an overboost condi-tion. Subject overboost conditions must be logged inthe engine log and inspections performed perLycoming Bulletin 369F.

DESCENT

CAUTION: Exercise care during descent to avoid exceedingVNE

FAA Approval: April 20, 1978Revised: Aug. 29, 1985 Report No. 28-AC-017

FM3-7

ENSfROM F28C

RUNNING LANDING

i. Maximum recommended ground contact speed is 35 MPH.Reduce speed on rough surfaces.

2. After ground contact, the helicopter must have zero forwardmotion before collective pitch is fully lowered.NOTE: Due to the high friction characteristics of the heli-

copters hardened steel skid shoes, premature low-ering of the colliective must be avoided as rapiddeceleration and nose down pitching may result.

PRELANDING CHECKS

1. RPM 2900

2. Fuel quantity3. Instruments

4. Mixture full rich

5. Boost pump check on

NORMAL ENGINE COOLING AND SHUT-DOWNPROCEDURE

1. Collective pitch full down and friction on2. Throttle full off

3. Fuel boost pump offNOTE: Leave boost pump on until engine stops where tem-

perature and altitude conditions preclude smoothidle engine operation with boost pump off.

4. Clutch disengaged, engine at full idle onlyCAUTION: Clutch disengagement with throttle down will result

in engine overspeed. Clutch disengagement is sig-naled by a red warning light on the instrument con-sole.

5. Cyclic control centered.6. Note engine idle RPM (with boost off) and turn fuel boost on.

Any difference in engine RPM noted indicates leaky idlemixture plates (refer to Enstrom Service Letter No. 0069).Slowly lean engine with mixture control short of cutoff posi-tion. An increase of 50 RPM indicates the idle mixture isimproperly set (refer to Enstrom Service Letter No. 0069).

7. Idle engine at 1800 RPM for 2 minutes or until cylinder headtemperature cools to 300 "F.

FAA Approval: April 20, 1978Revised: Aug. 29, 1989 Report No. 28AC017

FM3-8ENSTROM F28C

8, Radios off.

9. Lights off.10. Throttle full idle.

11. Mixture idle cut off,

12. When engine stops turning magnetos off.13. All switches off.

14. Master switch off.

15. Fuel valve closed tout).16, Set collective one-half way up in its travel to unload lamiflex

bearings.17. Tie down main rotor and tail rotor if wind speed is expected

to go over 30 mph,E,G,T, LEANING PROCEDURE CRUISE CONDITION

1. Attain the desired cruise flight condition.2. Maintain a constant altitude and manifold pressure setting.3. Trim out cyclic forces to maintain level flight.4. Turn mixture control to attain desired lean E.G.T, setting.

NOTE: Do not exceed 1650 "F E.G.T. Under certain highaltitudes and high O.A.T.s, near full rich mixtureswill be necessary to control cylinder head andengine oil temperatures. If the temperatures are toohigh, enrich in 25 "F E.G.T. increments until thetemperatures remain in the green are.

5. Any change in manifold pressure will require additional mix-ture adjustment.

FAA Approval: April 20, 1978Revised: Aug. 29, 1985 Report No. 28-AC-017

FM-4- I

ENSTROM F28C

SECTION 4 EMERGENCY ANDMALFUNCTION PROCEDURES

ENGINE FAILURE

1. Enter normal autorotation and stabilize at 58 MPH (minimumrate of decent). (See Height Velocity information, pages FM-5-4 and FM-5-5.)

~----i NOTE: Due to high rates of descent at forward speeds, sus-tained autorotation speed is limited to 85 MPH to8200 ft. Above 8200 ft., see FM-5-1.

Maximum glide distance in autorotation is attainedat 80 mph and 332 rotor rpm. (Reduce collective tobuild RPM prior to touchdown,)

2, Maximum recommended ground contact speed on preparedsurfaces is 35 mph. Reduce speed on rough surfaces.

3. After ground contact the helicopter must have zero forwardmotion before collective pitch is fully lowered.NOTE: Due to the high friction characteristic of the heli-

copters hardened steer skid shoes, premature low-ering of the collective must be avoided as rapiddeceleration and nose down pitching may result.

LIGHTING FAILURE

1. Landing can be made in case of landing light failure by illu-mination from navigation lights.

2. Instrument lighting is provided by eyebrow lights, internallights and map light. While satisfactory landings have beendemonstrated without instrument illumination, a supplemen-tal light source (flashlight) is recommended.

FIRE

Fires may have several sources of origin. Generally they may beclassified as engine compartment or cabin compartment, fuel oroil supported, or electrical.

FIRE ON GROUND

i. Shut off engine and all switches,2. Shut off fuel vfllvo.

FAA Approval: April 20, 1978Report No. 28-AC-017

FM-4-2

ENsTROM FZ8C

3. Determine source of fire and use fire extinguisher to extin-guish any flames.NOTE: Do not restart or fly aircraft until cause of fire is

investigated and corrected.FIRE IN FLIGHT

If the presence of odor and/or: smoke is detected, proceed asfollows:

1. Check instruments for correct reading.2. Shut off master and alternator switches.

3. Unlatch doors and let them trail open.

4. If smoke and odor persist, proceed to suitable area and landai re raft.

5. If inspection of aircraft indicates presence of flames, shut offengine and fuel valve and extinguish flames with fire extin-guisher.NOTE: If flames are present, do not attempt to start or fly

aircraft until the cause of the fire has been investi-gated and corrected.

Severe leakage of oil onto the exhaust system may cause con-siderable smoke to enter the cabin. In such case aircraft shouldnot be flown until cause of leakage is investigated and correct-ed.

TAIL ROTOR (Anti-Torque) SYSTEM FAILUREThere are two major possibilities for failure of the tail rotor (anti-torque) system and subsequent loss of directional control as fol-lows:

1. Failure of any portion of tail rotor drive system that causesstoppage or physical loss of the tail rotor blades.

2. Failure of any portion of the mechanisms that cause pitchchange of the tail rotor blades.

Upon loss of directional control, the pilot must immediatelydetermine the type of malfunction that has occurred (No. 1 or 2above) and select the proper emergency procedure.TAIL ROTOR DRIVE SYSTEM FAILURE

During hovering flight (aircraft will rotate rapidly to the rightwith full left pedal):

1. Cut throttle full off immediately (aircraft will slow down orstop its rotation),

FAA Approval: April 20, 1978 Report No. 28-AC-017

FM-4-3

ENSTROM F28C

2. Complete autorotatibnal landing.

During cruising flight (aircraft will rotate to the right with full leftpedal):

1. Power full off immediately, enter autorotation.

2. Complete autorotation to nearest suitable area.NOTE: If no suitable area is available within autorotative

distance, pilot should proceed as follows after hav-ing established stabilized autorotation with at least60 MPH airspeed.

1. Increase collective pitch and power gradually (maintaining60 to 80 MPH airspeed) until yaw to the right reachesapproximately 45 degrees.

2. Continue flight in this fashion using cyclic stick for directionalcontrol until suitable autorotational landing area is reached.

3, When 200 ft, altitude or more over suitable area, re-estab-

lish full autorotation and land.

TAIL ROTOR CONTROL SYSTEM FAILURE

NOTE: Loss of control may be caused by failure of leftpedal controls, right pedal controls or failure of pitchlink to an individual tail rotor blade. On the Enstrom

tail rotor, it is normal (if uncontrolled or unattended)for the blades to assume a nearly neutral pitch con-dition. Upon loss of ability to fully control tail rotorduring cruising flight, proceed as follows:

PITCH LINK FAILURE (One tail rotor blade)Aircraft will yaw to the right initially and will subsequently needan abnormal amount of left pedal to maintain straight and levelflight since only one blade is providing anti-torque thrust.

1. Fly at low cruise power to suitable landing area and makenormal power approach.

2. Complete a slow (less than 35 mph) run on landing at lowpower setling,

FAA Approval: April 20, 1978 Report No. 28AC-017

FM44

ENSTAOM F28C

FAILURE OF LEFT PEDAL CONTROLS

The direction and ambunt the aircraft yaws will depend on air-speed and amount of power applied at time of failure. At highpower and high airspeeds the aircraft will yaw right. At all air-speeds and low power settings below 23" Hg the helicopter willyaw left.. At low airspeeds where aerodynamic effects are negli-gible the helicopter will yaw left to approximately 80", hesitatebriefly, and then accelerate into 360" turns to the left. This condi-tion can be avoided by adding power to 24" Hg and acceleratingto 50 mph. The helicopter can then be flown to suitable area andlanded using the procedure below.

1. Remove feet from both tail rotor pedals.2. Maintain 24" Hg manifold pressure and 50 mph.3. Fly to suitable area and complete a shallow power on

approach at 50 mph.4. Manipulate power and collective pitch so that aircraft touch-

es down straight ahead at an airspeed of 0-10 mph. Reducepower and collective cautiously as skids contact surface.NOTE: Do not abort the emergency landing after airspeed

has diminished below 40 mph.FAILURE OF RIGHT PEDAL CONTROLS

Tail rotor control will be normal at power settings over 23" Hg.Power settings under 23" Hg will produce yaw to the left.Proceed as follows:

1. Fly to suitable landing area at power setting of at least 23"Hg.

2. Complete a shallow power on approach at 60 mph (do notautorotate).

3. Manipulate power and collective pitch so that aircraft touch-es down straight ahead at an airspeed of 0-10 mph. Reducepower and collective pitch cautiously as skids contact sur-face.

NOTE: Application of power to over 23" Hg will make air-craft more controllable. Therefore, landing attemptmay be aborted and new approach initiated asmany times as necessary

FAA Approval: April 20, 1878 Report No. 28-AC-017

FM-e5ENSTROM F28C

LANDING IN WATER (Ditching)DITCHING WITH POWER

If ditching is unavoidable without other recourse, proceed asfollows:

1. Descend to low hovering altitude over water.2. Unlatch both doors and exit passengers.3. Hover aircraft clear of all personnel in water.4. Turn off master and alternator switches.5. Complete hovering autorotation into water.6.As collective pitch reachesfull up and aircraft settles in

water, apply full lateral i=yclic in direction aircraft tends to roll.7.After rotor stnkes water and stops, climb out and clear

aircraft.

DliCHING WITHOUT POWERi. Tum off master and alternator switches.2. Unlatch both doors.3.Complete normal autorotation to land in water at zero

airspeed.4. As collective pitch reaches full up and aircraft settles in

water, apply full lateral cyclic in direction aircraft tends to roll.5. After rotor strikes water and stops, exit all occupants and

clear aircraft.

ALTERNATOR FAILURE

A malfunction of the altematorwill be indicated by zero charge rateor constant discharge on the ammeter. To put the alternator backon line, proceed as follows:NOTE: Use the following procedure if the alternator excite

circuit breaker (ALT EXC or ALTNTR EXC) is notinstalled

i. Altemator circuit breaker in.2. Cycle the MASTER and ALTERNATOR switches.3. If the alternator: is not restored or goes off line again, turn off

the alternator switch and all nonessential electricalequipment. Land as soon as pradicable.

NOTE: Use the following procedure if the alternator excitecircuit breaker (ALT U(C or ALTNTR U(C) isinstal led.

1. Alternator circuit breaker in.2. Altemator excite circuit breaker in.3. Cycle the ALTERNATOR switch.4. If the alternator is not restored or goes off line again, turn off

the alternator switch and all nonessentia I electricalequipment. Land as soon as practccale.

FAA Approval: April 20, 1978Revised: May 22, 1998 Report No. 28-AC-017

FM-4-6ENSTROM F28C

MAIN ROTOR GEARBOX

If, in nonnal flight, the main rotor gearbox red line temperature isexceeded, the aircraft should be landed at the next suitable landingsite

ELECTRIC FUEL BOOST PUMP

Failure of the fuel boost pump will be evidenced by illumination ofthe red low boost pressure waming light. In the event of a fuelboost pump failure, the helicopter engine will continue to operatein a normai manner as long as the engine driven fuel pumpcontinues to function properly.If the helicopter experiences a fuel boost pump failure, terminatethe night at the earliest practical time and have the malfunctioncorrected prior to next flight.CAUTION: If flight is continued after the fuel boost pump failure

and the engine-driven fuel pump malfunctions, theengine will stop due to fuel starvation. Gravity fuelfeed is insufficient to supply fuel to the engine.

LOW ENGINE OIL PRESSURE

If low oil pressure is accompanied by normal oil temperature, thereis a possibility the oil pressure gauge or relief valve ismalfundioning. This is not necessarily cause for an immediateprecautionary landing. However, a landing at the nearest airport-helipad would be advisable to inspect the source of trouble.If a total loss of oil pressure is accompanied by a rise in oiltemperature, there is good reason to suspect an engine failure isimminent. Reduce engine power immediately and select a suitableforced landing field.TURBOCHARGER FAILURE:(SEIZURE)Turbocharger seizure will be evidenced by a power loss (manifoldpressure drop) if operating at manifold pressures above ambientatmospheric pressure. It should be possible to maintain level flightat reduced airspeeds and altitude as the engine will then beoperating essentially as a non-turbocharged engine with manifoldpressure available essentially equal to ambient atmosphericpressure. A power check should be perfonned to confirm poweravailable for landing. A landing should be accomplished as soonas practicable. Plan for and perform a high altitude type (Nnning)landing, see page FM-3-7.

FAA Approval: April 20, 1978Revised: May 22, 1998 Report Na. 28-AC-0~7

FM-4-7ENSTROM F28C

ABNORMAL VIBRATIONS

Vibrations in this helicopter can usually be classified as either lowfrequency or high frequency. Low frequency vibrations aregenerally caused by the main rotor system while the highfrequency vibrations usually originate from the engine, drivesystem, or tail rotor. Any abnormal vibrations are an indicationthat something is not cx~rred and should be referred to a mechanicbefore further flight. If a vibration suddenly appears during a flight,it Is an indication that something has suddenly changed. Thehelicopter should be landed as soon as practical and inspected tofind the cause of the vibrations. After the cause of the vibrationhas been identified, the pilot and the mechanic can determinewhetherthe helicopter can be safely flown orshould be repaired onthe spot. An abnormal vibration is reason to get the aircraft downas soon as possible, but the pilot must also use caution and selectthe safest possible landing site, wor)ring around wires, people andother obstructions.

FAA Approval: April 20, 1978Revised: May22,1998 Report No. 28-AC-017

FM-51

ENSTROM F28C

SECTION 5 PERFORMANCEV never exceed VS. DENSITY ALTITUDE

(Vne demonstrated at 2750 engine rpm)2350 Ib. gross weight

MAX. APPROVED CEILING12000

10000

Vne(PWRION)

t 8000

0000

6

4000L3 Vne

(PWRIOFF)2000

S.L.

-2000

0 20 40 60 80 100 120

Indicated Airspeed M.P.H.

FAA Approval: April 20, 19f8 Report No. 28-AC-017

FM-5-2

ENSTROM F28C

AIRSPEED CALIBRATION

120

~f 100

so

ul

so

ow

~5: 40

c~ 20

0 20 40 60 80 100

INDICATED AIR SPEED M.P.H,

NOTE: Indicated speeds below 20 MPH are not reliable.

FAA Approval: April 20, 1978 Report No. 28-AC-017

FM5-3

ENSTROM F28C

MOVER CEILINGi IN GROUND EFFECT3H FOOT SKID HEIGHT

13000

\I\ n\Max. Approved Ceiling

1Xx~o cbc*

~t 10000

U.( I I \1\ 4\r$

sooo

sooo

u,3I

Standard Day4000

Max. Approved WeightXxx, i (2350 Lbs,)

S.L.

1800 1800 2000 2200 2400

FAA Approval: April 20, 1978 Report No. 28-AC-017

FM-54

ENSTAOM F28C

H EIG HT VELOCITY DIAG RAM

(Tests conducted on prepared surfaces)2350 LB. GR. WT.

AVOID OPERATION IN THISAREA

600O,G,E,Hoover May Be Precluded ByAtmospheric Conditions In This Area.

SAF5E OPERATING AREA600

Note:Critical points were demonstrated

at S,L, 8, 7000 Pt. Hdu

i Intermediate altitude curvesd 400 1~ \W"" developed analytically

k4) Tko(f Proflk

F300 XIC iJP

u

c XX,o,

I

IUI CIY(lon In Ih100 r to ~vdd

lo.n(cl ~t 1II rotorgurd with ground.

0 20 40 60 120

Indicated Airspee~ ~IPH

FAA Approval: April 20, 1978 Report No. 28-AC-017

FM-5-5

ENSTAOM 8288

EFFECT O F::OFFILOADINGON

CHOICE OF H-V ENVELOPE

The H-V envelopes shown on FM-5-4 must be used for the den-sity altitudes shown on the curves when operating at 2350 Ibs.Operations at gross weights less than 2350 Ibs, can be conduct-ed using a less restrictive H-V curve,

The chart below provides a method to select a more representa-tive envelope. For example, a gross weight of 2000 Ibs, and3900 ft, density altitude would allow use of the S.L. envelope(i,e, see example 1), A gross weight of 2200 Ibs. and 4500 ft.density altitude would require a 2800 ft. curve. To be consen/a-tive, use the next highest envelope, 4000 ft.

7000

8000?h,

Jx* C

LL

5000

C ;C

IfOQ) 024000 n

w 1

3000Examples IS

~Io,v, 2000P r

it:1000

1600 1800 2000 2200 2400

FAA Approval: April 20, 1978 Report No. 28-AC-017

FM-5-6

ENSfROM F28C

DENSITY ALTITUDE CHART

SET ALTIMETER fO 29.92 IN. HG.WHEN READING PRESSURE ALTITUDE

15,000 dP/14,000

43f

13,000 Cd~

12,000

11,00o

10,000

9000

8000

;i 7000 C~mla~p,

Z 6000

5000

,dS:4000

3000

2000

4

C?~: /1\1 ~FP/1000S.L.

--20 -10 0 10C 20 30 40 50Ly I I I I L .I-ll-1 I I 1 1 I0 10 20 30 40 50 60 70 80 90 100110120

F

OUTSIDE AIR TEMPERATURE

FAA Approval:April 20, 1978 Report No, 28-AC-017

FM-5-7

ENSTROM F28C

RATE OF ALTITUDE2350 LBS. GROSS WEIGHT

BEST RATE OF CLIMB SPEED VARIES WITHALTITUDE; 57 MPH AT S.L. DECREASING TO 49MPH, IAS AT 12,000 FT.

12000

10006

IL 8000

6000

?iC

4000

2000

400 800 800 1000 1200 1400

Rite Ot Climb, Feet Per Minute

FAA Approval: April 20, 1978 Report No. 28-AC-017

FM61ENSTROM F28C

SECTION 6 WEIGHT 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, emptyweight C.G. and useful loads are noted on the weight-balancesheet included in this Manual for this particular helicopter.The longitudinal and lateral c.g. range for the Model F28C varywith gross weight. Satisfactory aircraft handling qualities havebeen established throughout the c,g, envelopes shown on pageF=M-6-7 of this manual. Although the envelopes presented covera wide range of typical loading conditions, pilots must calculateany unusual loading conditions to insure that the aircraft c.g,remains in the approved envelope. Sample calculations areshown on pages FM-6-6 and FM-6-7 for reference.

The lateral c.g. limit is defined in terms of lateral moment in thatthe calculation of lateral c.g. is not part of the primary aircraftweight and balance records, Lateral moment is the algebraicsummation of the left and right hand loads times their respectivelateral moment arms. A sample calculation is shown on pageFM-6-6 for reference. The aircraft centerline is used as thedatum reference. Left lateral moment arms considered negative;right lateral moment arms are considered positive.

WEIGHT AND BALANCE

The removal or addition of fuel or equipment results in changesto the center of gravity and weight of the aircraft, and the per-missible useful load is affected accordingly. The effects of thesechanges must be investigated in.all cases to eliminate possibleadverse effects on the aircrafts flight characteristics.Maximum Gross Weight........,,,,.................~...........,..,..,.2350 Ibs.Estimated Empty Weight

(no accessories, fuel or oil) ,,.1495 Ibs.Useful Load

....................,......,.,.........,...................,,....,.,,.855 Ibs,Approved Forward C.G. Limit .2350 Ibs. station 92.0Approved Aft C.G. Limit............................2350 Ibs, station 94.6Approved Aft C.G. Limit. ........2000 Ibs. station 100.0

Report No. 28-AC-017

FM-6-2

ENSTROM F28C

Approved Lateral Offset Moment2350 Ibs.

.,.............................................-3250.+3700 in. Ibs.

Below 2015 Ibs., see FM-6-7.Centerline of aircraft is "O" lateral moment arm.

TOOLS AND EQUIPMENTTape Measure ......CommercialScale (two) ..................1 000 Ibs. capacityScale tail tone) ...............................................1 00 Ibs. capacityLevel bubble-type.... .........CommercialWork stand.............................~.....................................As required

DETAILED PROCEDURE FOR WEIGHING F28C 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 placedin a level flight attitude.

c, Check for proper installation of all accessory items, Check todetermine if the scales that are being used have been calibrat-ed recently, and check to see that the scales will zero outbefore weighing helicopter.

d. The helicopter will be weighed without fuel, but the weight andbalance record will reflect corrections to indicate the amountof unusable fuel 2 U.S. gallons. The helicopter may beweighed with full oil or without oil, but the weight and balancereport should be corrected accordingly.

e. Tare will be noted when helicopter is removed from thescales.

NOTE: Check oil level of main transmission and tail rotortransmission, Check to see that the main rotorblades are in uniform position, 120" 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.

Report No. 28-AC-017

FM-6-3

ENsTRoM F?BC

i. Position a pipe nipple in the center of left and right handscales at 17.7 inches aft of the center line of the forward 3-inch diameter aluminum landing gear cross beam assembly.(Detail No. 1)The 17.7 inch dimension must be taken perpen-dicular to the centerline of the helicopter.

In order to simplify defining the fulcrum position, Enstrom toolT-1794 is shown below. This tool may be purchased through theEnstrom Customer Service Department.

WEIGHT AND BALANCETOOL POSITIONING

Detail No. i

ORIGINALAs Received By

ATP

RBPOTt ND. 2B-*C-017

FM-6-4

ENSTROM 280C

ORLGINACFig. 1 As.8Rceived By

ATP

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

identified. (Detail No. 2). Fig. i.i. Lateral level taken at lower forward pylon tube

m. Small scale will be located under tail rotor at the center line ofthe tail rotor output shaft, Fig. 2.

n. Vsing 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.

o. Read and record weight from each of three scales.

p. Calculate weight and center of gravity on attached form, withweight data. Empty weight will be "dry weight."

q. All items added or subtracted will be listed on the attachedform with weight, arm, and moment.

Rspon No 28-AC-017

ORIGINALAc Received By FM-6-5

ATP ENST~MF28C

Fig. 2

CAUTION: Weight and measurement headings 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 connectionwith each helicopter presented for air-worthiness certificationat the Enstrom Corporation. All these reports are marked"actual weight."

t. This weight and balance report, and equipment list will be pre-pared and supplied with each helicopter.

u. Use Form No. F-165 (page FM-6-9) Basic Weight andBalance Report to give you a continuous history of weightchanges throughout the life of your helicopter.

Report No. 28P1C017

FM-6-6

ENSTROM F28C

LOADING INFORMATION

NOTE: It is the responsibility of the helicopter pilot to insurethat the helicopter is loaded properly. The emptyweight, empty weight c.g. and useful load are notedon the weight and balance sheet included in thismanual for this helicopter.

C.G.Range: Variable with Gross Weight 92.0 to 100

Maximum Gross Weight ..........................2350 Ibs.TYPICAL LOADING F28C

Weight Arm MomentRearward C.G. (Ibs.) tin.) tin. Ibs.)Empty Weight (includingundrainable engine oil,gearbox oil and unusablefuel) ....1495.0 101.4 151593.0Baggage Box 10.0 135.0 1350.0Engine Oil 15.0 100.0 1507.5Pilot 120.0 62.0 7440.OBaggage 60.0 135.0 8100.0

99.99 169990.5

Weight Arm MomentForward C.G. (Ibs.) tin.) tin. IbsEmpty Weight .......1495.0 101.4 151593.0Baggage Box 10.0 135.0 1350.0Additional Panel Instr. 20.0 36.0 720.0Engine Oil 15.0 100.5 1507.5Fuel, 40.0 Gal.

..........................240.096.0 23040.0

Pilot Passengers 530.0 62.0 32860.040 Ibs. of Baggage 40.0 135.0 5400.0

2350.0 92.11 216470.5Lateral Offset Moment

Pilot (left seat) .........190 -13.5 -2565.0Copilot (right seat) ...130 +12.12 +1575.6

-989.4

(Centerline of aircraft is "zero" lateral moment arm)

Report No. 28-AC-017

FM-6-7

ENSTR6M ~F28C

APPROVED CENTER OF GRAVITV ENVELOPESLONGITUDINAL C,G.

240025~6--jl

2200

aoooI nPpAov~o nqEn

1800

160092 94 96 98 100

LONGITUDINAL C.G. -INCHES AFT OF DATUM

LATERAL OFFSET MOMENT ENVELOPE

2400(I -L1I~ 1) 7

2200

ui I I I I APPROVED AREA

Si I I I I,

v, I II I I I I/

Ieoo

v

leOO-4000 -2000 O 2000 +4000

LEFT RIGHTLATERAL OFFSET MOMENT

(IN. LBS.)

Report No. 28-AC-017

FM-6-8

ENSTROM F28C

ENSTROM F28C EQUIPMENT LIST

Serial No.

FAA Approved Registration NO. Date

Check DateNo. Item Wt. ArmOn 011

INSTRUMENTS REQUIRED

Aitimeter 1 1.2 36Airspeed .5 36Tachometer 1.3 36Manilold Fuel Pressure 1.5 36Instrument Cluster 2.0 36

Oil TemperatureOil PressureGear Box TemperatureCylinder TemperatureFuel QuantityAmmeter

Compass 1.0 40OAT Gauge 0.5 55Ball Bank IndicatorE.G,T, Gauge 0.5 36OPTIONAL EQUIPMENT

1 Night lighting equipment (including combinationstrobe and position lights, internally lit instrumentcluster)

2 Map light (Reqd for night flight) .5 803 8dayclock 1 .5 384 Hour meter .75 885 Soundproofing6 Defroster F28A, F28C7 Strobe lights F28A8 Float build up9 Center radio console (F28A, F28C)

10 Cargo Hook1~ Extra head set 2.0 8012 Cabin heater g delrosler combination 280, 280C 3.5 4813 Snow shoe installation I 18.0 100.914 Cabin healer (F28A, F28C) 4.1 36.0t5 Baggage compartmenl 10.0 135.0(6 Flolation gearlwilh hardware17 Dual controls 12.0 5018 Floor carpet, int. trim 8 headliner 6.0 66.019 Fed. 12V. twin speaker--siren 11.3 7920 Litter kit-single 24.0 100.021 King KT 76 transponder 4.0 34.022 Shoulder harness wlreel single 3 8223 Shoulder harness wlreel double 6 8224 First aid kit 5.2 13525 Ashtrays 8 lighter 1.0 32.026 Fire extinguisher 5.7 80.027 External power unit (APU) 1.0 76.028 Narco com 11 An wlintercom 4.0 34.029 Narco nev 11 3.5 32.030 Narco ADF 140 4.3 33.031 Nerco DME 190 6.6 34.032 Narco ATS0A transponder 4.2) 34.033 King KR88 ADF 3.9 34.034 Oyro horiron model R,C. Alien 25 3.4 32.035 RCA-1SA1 directional gyro 2.3 31.036 King KX1758 NAVICOM 7.0 34.037 ADF 140 loop (L sense antenna 3.1 138.038 Presidentlat doors (door pockets) 6.0 60,039 Instantaneous vertical speed indicator 1.3 34,040 Aim 200 directional gyro 3.8 39.041 Antenna (vor) 1.3 194.042 Nerco 00010 4.7 32.043 Deul lending Ilght (Reqd for night flight) 3.2 25.044 King KR 85 wlindicator 7.0 34.045 Chadwick lank46 Ground handling wheel(s) 13.0 104,747 King Kl-225-01 indicator 1.3 34.048 Narco NAV 14 2.25 34.049 Narco ELT 1 3.3 135

Standard equipment not requ(red by FAA.

*Standard equipment not required by FAA,Report No. 28-AC-017

i B

Item Weight added Weight removed Running bezic total n,oItem co o

Date Desaiption of article or modification s aNo. Inl Out Weight ArmlMom.lW~ightlArm Mom.lWeightlC.G. /Mom.~o it m

ACTUAL DELIVERED WEIGHT AND BALANCE DATA I 1 I I acr V)

71

I I I I I I I I I I -I I I I 1z ImOo o m

371 I I I I 1 I I I I t I I I a, Ic~1,a, (p

mz z

cn

z

U OI 13

m 71I h,

r mo o

r

II zo 11 O

Dm

n I ;1)n I I 1 i I 1 1 I i 1 i I r I C. It,(D o a

o 3Oo

I I I I I 1 I I I I I I I I I I OIr f i I I 1 I I I I I I I I I I c 11 30

m II Dhi(3)

(D-n

o

b 5 11 I ir,co cb

FM-6-10

ENSTROM F28G

WEIGHT AND BALANCE REPORT

(00.0C ROTOA Hue

11-"1

ge~01)9.75LCGO

0 64.0 93.446 135.0 320.0FWD AFT

WEIGHING WEIGHINGSTATION STATIONWL WA WT

Modal Serial No. Registra~ion No.

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

Left gear (W,)Right gear

Tail (WT)Total

WT (320.0) (WL WRI (93 4461LCGWT C W~+ WR

Date Weighed by

Form No. F-166 Report No. 28-AC017

FM6-11

ENSTROM F28C

AIRCRAFT ACTUAL WEIGHT REPORTModel Serial No. keo. No.

(Standard equipment not installed( IOptional surplus equipment inat weighin aircraft at weighin

Moment X I I I I Moment XItem No. Wt. Arm 1000 in./lbr.l I Item No. Wt. Arm 1000 in./lb~.

Total I I I I I Total

We10hin0 wItneseed by DateForm No. F167

Report No. 28-AC-017

FM-6-12

ENSTROM F28C

AIRCRAFT WEIGHT AND C. G. CALCULATIONModel Serlsl No. ReO No.

Weight Arm MomentIbr, in. 1000 in.llbr,

Weight let weighed)

Le~r: optional iurplur weight

Plui: miuing ~td, equipment

ComputedTotel Hieight empty ~td, eircrft

Actuel

Plur: engine oil

Flue: optionel equipment 8 ki(i

fotl b~ic weight

Form No. Fl~

Report No. 28-AC-017

FM7-1

ENSTROM F28C

SECTION 7 AIRCRAFT AND SYSTEMDESCRIPTION

One of the first steps in obtaining the utmost performance, ser-vice, and flying enjoyment from your F28C, is to familiarize your-self with its ecluipment, systems, and controls.The Enstrom F28C Helicopter is designed for high performance,mechanical simplicity, and maximum versatility. By virtue ofcomponent longevity and minimum maintenance requirements,the F28C enjoys the lowest operating cost of any helicopter. Therugged, patented rotor head, combined with the (51 Ibs. each)rotor blades, gives unheard of stability and excellent autorota-tional characteristics.

INTERIOR ARRANGEMENT

The cabin interior is a full, three-place, side-by-side seatingarrangement with a spacious 61" width for maximum pilot andpassenger comfort and safety. The instrument panel is on thevertical plane for more natural scanning and is convenientlylocated for dual pilot viewing. Excellent visibility is offeredthroughout the tinted Plexiglas windshield and doors with over-head and lower deck windows. Extra-width, swing-open doorsclose securely with simple-to-operate safety lock handles. Thehelicopter can be flown with either left, right, or both doors off.

AIR INDUCTION SYSTEM

The air induction system consists of a filtered non-ram air intakelocated within the engine campartment. It incorporates a spring-loaded, automatic alternate air source.

POWER PLANT

An Avco Lycoming HIO-360-E1AD 205 he engine is used in thishelicopter. The engine is a direct drive, four cylinder, fuel inject-ed, horizontally opposed, air cooled engine, This engine incorporates features for turbocharging. Platinum spark plugs aresupplied with the engine.

NOTE: It is recommended that the appropriate LycomingOperators Manual be consulted prior to any adjust-ment or repair to the engine.

Report No. 28-AC-017

FM-7-2

ENSTROM F28C

OIL SYSTEM

The Lycoming engine employs a wet sump lubrication systemhaving a capacity of 8 quarts. The engine oil pump circulates theoil through a remote mounted oil cooler to provide cooling.lt islocated on the right-hand side of the engine compartment. Athermostatic bypass and pressure relief valve are supplied asstandard equipment. Restricted pressure engine oil is also circu-lated through the turbocharger bearing housing. A separateengine scavenge pump returns the oil to the engine sump. Abayonet-type oil quantity gauge with graduated markings is partof the oil filler cap and is accessible through the left fuel drainaccess door.

The total oil system has a capacity of 10 quarts. This includesthe oil in the engine, oil filter, oil cooler, and oil lines.Oil System Indicators-0il Temperature and Pressure Gauges.Standard type gauges are pro~ided for both the engine oil tem-perature and oil pressure indications. Both gauges are markedto provide visual engine operating limitations and are located onthe instrument panel.

ENGINE CONTROLS

Throttle. A twist-grip type throttle is located on the collectivepitch control stick for direct control of engine power. It is manual-ly connected to the fuel servo-throttle valve on the engine.Mixture Control. A vernier mixture control knob is provided onthe instrument console. This vernier control incorporates the fea-tures of a standard push-pull cable. Full rich is in the "in" posi-tion. Full lean is in the "out" position. The vernier feature allowsa screw type of adjustment tP fine tune any preset mixture posi-tion.

Magneto Switch. The magneto switch is a key-operated switchlocated on the left side of the switch circuit breaker panel. Forstarting, place the switch in the "Both" position.Ignition Safety Switch. This switch closes the circuit to thestarter button on the collective control.

Stat~er Button. The starter button is located on the end of thecollective control. Push to engage.Master Switch. The master switch is located on the left side ofthe switch circuit breaker panel. It is a single-throw, two-positionswitch.

Report No. 28-AC-017

FM-7-3

ENSTROM F28C

TURBOCHARGER

The turbo unit has only one moving part, a rotating shaft \t~itt, a tur-bine wheel on-one end, a compressor impeller on the other, all pre-cision balanced and each contained in its own housing. The turbinewheel, driven by exhaust gas energy, drives the impeller whichcompresses intake air to a density equivalent of near sea revel anddelivers it to the engine intake~ Shis increased volume of air allowsthe engine to "f~reath" with the same volumetric efficiency that itdoes at low levels. The engine can produce the equivalent power ata)) altitudes up 5a12,000 feet density altitude.EXHAUST GAS TEMPERA7URE SYSTEM

The exhaust gas temperature, as shown on the panel mounted indi-cator, is used as an aid for fuel mixture leaning in cruising flight.fhe panel indicator is red-lined at 1650 "F. The exhaust tempera-ture probe is located on the exhaust stack lust before the inlet to theturbocharger. This allows an actual temperature measurement ofthe exhaust gases that are delivered into the turbocharger unit.CABIN HEAT

The cabin heat control is located at the left-hand side of the pitotsseat, on the floor, By moving the control in or out, the operator regu-lates the amount of cabin heat through the output louvers located inthe center of the floor under the instrument panel.CLUTCH ENGAGING LE\IER

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

as a means of engaging and disengaging the rotor drivesys(em~ The rotor drive system is engaged by pulling the clutchlever upward and rearward until the lever hits the stop and thewarning tight goes out. The handle can then be stowed by lifting itstraight up and pivoting it down to the floor, When it is in the stowedposition, the handle should lie flat on the floor, If it does not tie flaton the floor in the stowed position; the clutch rigging should be

as described in Section 8 of the Maintenancs Manual. Theclutch lever must be stowed whenever the rotor drive system isengaged.FUEI, SYSTEMThe system consists of two interconnected 20 US gallon fueltanks, which feed simultaneously to the engine. 7he tanks arelocated on the left and right side of the aircraft over the enginecompartment. The tanks have a total fuel capacity of 4Q US Qal-ions, with a total of two gallons unusable fuel, one gallon unus-able fuel in each tank,,Each tank is gravity fed to a centralFAA Approved: Ap~li 20, 1978Revised: August 29, 1985 Report No. 28ACD17

FM-7-4

ENSTROM F28C

distributing line which connects to the electric boost pump andengine driven pump. The fuel control valve is an off-on type andis located on the firewall next to the pilots left shoulder. Eachtank has an individual drain valve in the bdtto~. There is also amain gascoiator filter located aft of the firewali in the enginecompartment. The control is on the right-hand side of the enginecompartment and extends beyond the side panel.Auxiliary Fuel Pump Switch The fuel boost pump switch andfuel pressure warning lights are located on the switch circuitbreaker panel. The green warning light will stay illuminated aslong as the fuel boost pump is operational. The red light will illu-minate at any time the fuel boost pump is shut off or fails tofunction properly.Fuel Quantity Indicator. The fuel quantity gauge continuouslyindicates the total quantity of fuel. It is hooked up through a sim-pie type liquidometer float located in the right-hand fuel tank. Atranslucent strip on each tank provides a direct, visual indica-tion of fuel level.

Fuel Flow-Fuel Pressure Indicator. The fuel pressure providespounds per hour and pressure readings of the fuel as deliveredto the flow divider. The indicator is marked for normal operatingrange from 0 to 160 pounds per hour and 0 to 25 psi index linesin 5 psi increments.TRANSMISSION SYSTEMThe main transmission unit provides an 8.277 reduction ratiobetween the engine and the main rotor. The transmission incor-porates a free-wheeling unit in the upper pulleyassembly whichis mounted on the pinion input shaft. The free-wheeling unit pro-vides a disconnect from the engine in the event of a power fail-ure and permits the main and tail rotors to rotate in order toaccomplish safe autorotation landings. Six pints of S.A.E. 90 wt.E.P, gear oil are used in the transmission. The main rotor trans-mission has a sight gauge which is located on the aft right-handside and is visible through an opening in the baggage compart-ment or the right access panel.Main Rotor Transmission Temperature Indicator. A mainrotor transmission gauge is located on the instrument panel andis redlined at 220 "F.

Tail Rotor Transmission. The tail rotor transmission, mountedat the aft end of the tail cone, supports and drives the tail rotor.The tail rotor transmission is equipped with a self-containedlubricant supply and level gauge at the rear of the housing andmagnetic plug can be removed to inspect for metal particles. Its

Report No. 28-AC-017

FM-7-5

ENSTROM F28C

capacity is 5 ounces of S,A.E:il-lOl~;r i~n-detergent motor oil.ROTOR SYSTEM

Main Rotor. The main rotor is a three-blade, fully articulatedsystem. The fully articulated system in the F28C Helicopter pro-vides smooth control responses in all modes of flight; and due tothe kinetic energy stored in the heavy rotor blades, allows foreasy-to-perform, safe autorotation landings in the event ofpower failure. The rotor assembly consists of three all-metalbonded blades, upper and lower rotor hub plates, universalblocks, blade grip assemblies, and lead lag hydraulic dampers.Tail Rotor. The tail anti-torque rotor counteracts the toque of themain rotor and functions to maintain or change the helicopterheading. The tail rotor is a two-bladed, teetering, delta-hingetype assembly.Rotor Tachometer. The rotor RPM indicator is part of a dual-purpose tachometer which also reads engine RPM.FLIGHT CONTROLS

Cyclic Control. The cyclic control stick is similar in appearanceto the control stick of a fixed-wing aircraft. The direction of stickmovement results in a change of the plane of rotation of themain rotor and will produce a corresponding directional move-ment of the helicopter through the longitudinal and lateral modesof flight. The stick grip incorporates a trigger-type switch usedfor radio transmissions and intercom. A trim switch is also locat-ed on the cyclic stick grip to control the longitudinal and lateraltrim motion.

Stabilizer. An all-metal, fixed-position stabilizer is installed onthe tail cone assembly for longitudinal trim.Collective Pitch Control. The~collective pitch control lever islocated to the left of the pilots position and controls the verticalmode of flight. A rotating, grip-type throttle is located at the endof the collective control.

Directional Control Pedals. The directional control pedals arelocated in the cabin forward of the pilot and/or co-pilot. Whenmoved, these adjustable pedals change the pitch of the tail rotorblades and thereby provide the method of changing directionalheading.

Report No. 28-AC-017

FM-7-6

ENSTROM 8282

FLIGHT .INSTRUMENTS

The standard flight instruments which are installed in the F28Cas basic equipment comply with the requirements under visualflight rules for day or night operation. The panel arrangementprovides ease of visual observance and includes space provi-sions for installation of additional instruments to meet individual

requirements.Airspeed Indicator. The single-scale airspeed indicator is cali-brated in MPH and provides an indicated airspeed reading dur-ing forward flight. The pitot tube, which provides air pressuresource, is located below the cabin nose section. Static air pres-sure for instrument operation is derived from two static ventslocated on either side of the tail cone assembly. The openings inthe pitot tube and static vent ports must belmaintained obstruc-tion-free and clean at;iil times for proper instrument operation.Altimeter. The altimeter is a sensitive type that provides dis-tance-height readings from O to 25,000 feet. The long hand in asingle complete sweep of the dial totals 1,000 feet, and the shorthand totals the thousands of feet altitude. The instrument isvented to the same static port vents as the airspeed indicator.

Compass. A standard aircraft eluality magnetic compass ismounted on the center windshield support within easy sight ofpilot or co-pilot. It is to be used in conjunction with a compasscorrection card located adjacent to the instrument.Free Air Temperature Indicator. The free air temperature indi-cator is a direct reading, bi-metallic instrument with a stainlesssteel probe. This instrument provides ambient temperature infor-mation which, when utilized, will assist in determining perfor-mance capabilities of the helicopter at the existing climatic con-dition. The indicator is located in the top of the cabin.

ELECTRICAL POWER SUPPLY SYSTEM

Direct Current Power System. The basic power supply systemis a 12-volt direct current system, with a negative ground to thehelicopter structure. A belt-drive 70 amp alternator is located onthe aft part of the engine. One 12 volt battery is located in theright-hand side of the pilots compartment and serves as astand-by power source supply power to the system when thealternator is inoperative.

Report No. 28-Ac-017

FM-7-7

ENSTROM F28C

OBIGINAba:i::;-i-(;:,-: Asi Weceived By

ATP

_I Q

28

1112

14

00000~00

F28C INSTRUMENT PANEL

1. Manifold pressure/fuel flow 15. Engine hour meter2. Fuel quantity (not shown)3. Oil pressure 16. Clock (not shown)4. Main rotor-gear box 17. Instrument lights5. Oil Temperature !8. Navigation lights6. Ammeter 19. Anti-collision lights7. Cylinder temperature 20. Landing light8. Altimeter 21. Alternator switch

9. Airspeed 22. Panel light circuit breaker10. Rotor/engine tachometer 23_ Bank indicator11. Panel light dimmer switch 24. Mixture control12. Ignition switch 25. Compass13. Master switch and circuit breaker 26. Ignition safety switch14. Fuel pressure indicator and boost 27. Trim motor switch

pump switch. 28. EGT gauge

Report Na. 28-AC-017

FM-7-8

ENSTROM F28C

Electrical Power Panel. The following switches/combination cir-cuit breakers are located on the switch circuit breaker panelmounted on the instrument console within easy reach of pilot orco-pilot: magneto key switch, master switch, alternator switchand alternater circuit breaker, boost pump switch, navigationposition lights switch, anti-collision light switch, landing lightswitches, panel light switch, starter switch, and trim motorswitch

LIGHT1NG EQUIPMENTThe helicopter lighting kit includes the required tights necessaryfor VFR night operation plus additional lighting equipment forutility and convenience purposes. The electrical panel on theright-hand side of the instrument console contains the protectivecircuit breakers and control: panels for the lighting equipment.Position Lights. Two position lights are located one on eitherside of the forward cabin structure and two lights are located aftof the stabilizer on the tail cone.

Anti~Collision Lights. The anti-collision lights have a rotating,flashing action that privides for adequate identification of thehelicopter. One anti-collision light is located on top of the fuse-lage aft of the cabin, and the other light is located forward of thecabin structure under the pilots compartment, They are operat-ed by the anti-collision switch located on the panel.Landing Lights. The landing lights are of the permanent extendtype, one is mounted on the nose and the other on the under-side of the aircraft and set in the desired angle for the best for-ward and down illumination. The switches for operation of thelanding lights are located on the instrument panel in the electri-cal console section. The light on the underside of the aircraft isprimarily designed to provide illumination while hovering.

GROUNCI HANDLING WHEELS

Each landing gear skid tube has a manually operated over-cen-tering device to lower the wheels or retract them for flight. Theground handling wheels should be retracted and the helicopterallowed to rest on the skids when engine run-up is being per-formed or when helicopter is parked.

Report No. PB-AC-O11

FM-7-9

ENSTROM F28C

BAGGAGE COMPARTMENT

The compartment for storage of baggage is provided in the areaaft of the engine compartment. Access is through a single doorlocated on the right-hand side which has a locle for external lock-ing. The capacity of the compartment is approximately 10 cu. ft.and has an allowable loading capacity of 60 ibs. at Station 135.

FUEL SHUTOFF

CONTROL

ROTOR CLUTCH

COLLECTIVE CONTROL

COLLECTIVE TiiiC1 ON

AIL ROTOR PEOALS

ARTER aUTTON

ORIGINALR~port No. ZBAc4(7As Received By

ATP

FM-8-1

ENSTROM F28C

SECTION 8 AIRCRAFT HANDLING,SERVICING AND MAINTENANCEIf you wish to obtain maxi:mum performance and dependabilityfrom your F28C Helicopter, certain inspection and maintenancerequirements must be followed. It is always wise to follow aplanned schedule of lubrication and maintenance based on theclimatic and flying conditions encountered in your locality. Keepin touch with your Enstrom dealer and take advantage of hisknowledge and experience. Your dealer is ready and willing toassist you and to keep you abreast of all changes, whether it bemaintenance or periodic servicing of the helicopter.GROUND HANDLING

To lower the ground handling wheels, insert the slotted handlefacing forward. While applying a constant pressure to handle,release pin. Pull up and aft with a lifting motion until the holesline up. Insert the locking pin. Keep a firm grip on the handleuntil pin is in place.CAUTION: 1. Keep your feet from under the skids.

2. Stay on outside of skid, do not straddle.MOORING

Although it is not generally necessary to tie down the helicopter,a nylon rope can be attached to the landing gear cross tube atthe oleo attach points. One blade should be placed parallel totail cone and tied to tail cone.

TRANSPORTING

If transporting helicopter on trailer or truck, skids may besecured to bed of trailer allowing oleos to function.a. Remove three main rotor blades and store in blade box.

b. Secure tail rotor.

c. Disconnect battery.STORAGEThe metal-fiberglass construction of your F28C makes outsidestorage practical, although inside storage will increase its lifejust as inside storage will increase the life of your car. If yourF28C must remain inactive for a time, cleanliness is probablythe most important consideration. It is suggested that a canvasor nylon cover be placed over the rotor head. If storage is for anextended period, see your Lycoming Manual for preservationinformation

Report No. 28-AC-017

FM-8-2

ENSTROM F28C

HOISTING

To lift the entire helicopter, the use of a nylon sling of approxi-mately 3,000 Ibs. capacity is required. The nylon sling is placedaround each grip assembly.JACKING

It is possible to jack up the helicopter inboard of upper oleoattach points on forward and aft cross tubes.CAUTION: Support the tail cone at extreme end.EXTERIOR PAINT

The finish of your helicopter should be kept clean. It requires nospecial care. When washed, however, water should not besprayed directly into any bearings. Any good grade of car waxwill help to maintain the condition of the factory finish. It is veryimportant that the main rotor blades be kept clean and free ofdirt. After all, the blades arean airfoil, and to get maximum lift,they must be clean.WINDOWS AND DOORSThe windows and doors are made from a fine grade of acrylicplastic. These surfaces can be scratched if dirt, bugs or otherforeign material are not removed promptly. If the windshield isexcessively dirty, a water and mild soap solution will help lift thedirt.

CAUTION: Never take a rag to wipe dirt from the glass areason your helicopter. There are many good productsmade especially for the cleaning of acrylic plasticsurfaces

UPHOLSTERY AND CARPETS

No special care is required to keep the interior of your helicopterclean. A good stiff broom will help remove the imbedded dirt;vacuum the interior whenever possible. Any good upholsterycleaner can be used on the carpets and seats, but a word ofcaution when cleaning the seat belts. They are nylon, and cer-tain cleaning agents will destroy the material used in their con-struction.

LANDING GEAR SHOCK STRUTS

The oleo struts are of the air-oil type and require little mainte-nance. It is suggested that the oleo be wiped off frequently tokeep the abrasive action of dirt and oil to a minimum.

Report No. 28-AC-017

FM-8-3

ENSTROM F28C

AIR CLEANER OR FILTER

The air cleaner is an important part of your engines inductionsystem. If it becomes dirty or clogged, your engine will use morefuel and will not produce maximum power. Excessively dirty fil-ters will allow particles of dirt to be sucked into the cylinders,causing major damage. If your helicopter is operated in anydusty and high grass areas, check the air filter more frequently.LIGHTS

Check the electrical system of the helicopter daily and alwaysbefore night flying is planned. Keep the light lens clean for maxi-mum brilliance.

BATTERV

The battery will normally require only routine maintenance.However, if you should operate in a warm climate, an occasionalcheck for fluid level is recommended. Keep the battery terminalsand battery compartment free of corrosion.

DAMPERS-MAIN ROTOR

To check for lead-lag operation, raise the blade off its droop stopand move each blade fore and aft by gripping blade at tip. Aresistance indicates damper operation. There should be noundamped motion.TRANSMISSION-MAIN

The transmission requires no special attention other than check-ing the sight gauge on the rear of the transmission on the right-hand side.

TRANSMISSION-TAIL ROTOR

The transmission requires no special attention other than check-ing the oil