bht-412-fm-4 bell 412ep flight manual

POST OFFICE BOX 482 FORT WORTH, TEXAS 76101

BHT-412-FM-4

NOTICE

Please insert attached BHT-412-FM-4, REVISION 24 dated05 NOVEMBER 2002 into Flight Manual in accordance with Log ofPages.

23 JUNE 1994REVISION 24 05 NOVEMBER 2002

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BHT-412-FM-4

ROTORCRAFTFLIGHT MANUALBHT 36087 AND SUBSEQUENT

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COPYRIGHT NOTICECOPYRIGHT 2002BELL HELICOPTER TEXTRON INC.AND BELL HELICOPTER TEXTRONCANADA LTD.

ALL RIGHTS RESERVED


BHT-412-FM-4

ROTORCRAFTFLIGHT MANUAL

BHT 36087 AND SUBSEQUENT

THIS MANUAL SHALL BE IN THE HELICOPTER DURING ALL OPERATIONS

23 JUNE 1994REVISION 24 05 NOVEMBER 2002

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BHT-412-FM-4

NP Rev. 24 05 NOV 2002

Additional copies of this publication may be obtained by contacting:Commercial Publication Distribution Center

Bell Helicopter Textron Inc.P. O. Box 482

Fort Worth, Texas 76101-0482

NOTICE PAGE

Manufacturers Data portion of this supplement is proprietary to BellHelicopter Textron Inc. Disclosure, reproduction, or use of these data forany purpose other than helicopter operation is forbidden without priorwritten authorization from Bell Helicopter Textron Inc.

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BHT-412-FM-4

MODEL

ROTOR CRAFTFLIGHT MANUAL

(f U 36087 AND SUBSEQUENT

GHIORARY REVISIONMAST TFRQf SIGNAL CONDITIONER

-v/ M 32-97-90

This Temporary Ren current publishedperfrmance and pro ew ace data aftercompliance with ASB 412

Attach these temporary revis^e ? like numberedpages in light Manual after con 412-97-90.

DO NOT remove existing pages rua

Infornaton contained herein suppenn basicFlight Manual. For Umitations, Proced acData not contained in this supplement, Manual.

THIS MANUAL SHALL BE IN THE HELICOPTER DURING T

Bell HelicoptertmE lr'l' lCOfRIIT NOICE A Suidauy t tton It,

COpYRulIr 2000BlDTULICPTER ia RSN 2i oA DIVSION OF TERf LTD 23 JUNE 1994

AL RIGHnS RESolD TEMPORARY REVISION - 8 AUGUST 1997CANCELED - 5 SEPTEMBER 2000

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BHT-412-FM-4

ROTOR CRAFT

FLIGHT MANUAL

SIN 36067 AND SUBSEQUENT

TEMPORARY REVISION

MAST TORQUE SIGNAL CONDITIONER

ASB 412-97-90

THlS MANUAL SHALL SE IN THE HELICOPTER DURING ALL OPERATIONS

Bell

TEMPORARY REVISION - 8 AUGUST 1997 REVlSlON 1 - 18 DECEMBER 1997

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LOG OF REVISIONS

Temporary 8 AUG 97 Revision 1 .......... 18 DEC 97

LOG OF PAGES

Revision Page NO. Page

Title Temp/REV 1 A-B . . . . . . . . . . . . . . . . . . . . ..Temp/Rev 1 NOTE: Figures 4-4 through 4-8 are provided in their entirety for ease of handling 4-11 4-15 ..... Temporary 4-15A-4-15H Temporary 4-16 -4-18 (no change) Temporary 4-19 -4-30 Temporary 4-30A - 4-30M Temporary 4-31-4-36 ................................... TemplRevl

Revision NO.

TEMPORARY REVlSlON - 8 AUG 97 REVISION 1 -18 DEC 97 A

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BHT-412-FM-4

05 NOV 2002 Rev. 24 A

NOTE

Revised text is indicated by a black vertical line. Insert latest revision pages; dispose of superseded pages.

LOG OF REVISIONS

Original ....................... 0.................... 23 JUN 94Revision ...................... 1.................... 23 DEC 94Revision ...................... 2.................... 06 JUN 95Revision ...................... 3.................... 23 JUN 95Revision ...................... 4....................29 AUG 95Revision ...................... 5.................... 26 OCT 95Revision ...................... 6.................... 23 FEB 96Revision ...................... 7....................22 AUG 96Revision ...................... 8.................... 10 SEP 96Revision ...................... 9................... 12 MAR 97Revision ..................... 10.................. 12 MAR 97Revision ..................... 11....................23 JUL 97Revision ..................... 12...................08 AUG 97

Revision......................13 .................. 14 NOV 97Revision......................14 .................. 14 NOV 97Revision......................15 ..................26 MAR 98Revision......................16 .................. 21 APR 98Revision......................17 .................. 14 MAY 98Revision......................18 .................. 28 OCT 98Revision......................19 .................. 20 DEC 99Revision......................20 .................. 26 MAY 00Revision......................21 ...................05 SEP 00Revision......................22 ...................11 JUN 01Revision......................23 .................. 23 MAY 02Revision......................24 .................. 05 NOV 02

LOG OF PAGES

REVISION REVISIONPAGE NO. PAGE NO.

Cover........................................................24Title...........................................................24NP.............................................................24A B .......................................................24C/D............................................................24i ...................................................................0ii ................................................................19iii/iv .............................................................01-1.............................................................181-2.............................................................191-3.............................................................241-4.............................................................231-4A/1-4B .................................................181-5.............................................................201-6.............................................................221-7...............................................................91-8 1-10 ................................................171-11...........................................................231-12...........................................................191-13 1-16 ................................................51-17...........................................................201-18 1-21 ................................................51-22...........................................................17

1-23 1-24 ............................................. 102-1 2-2 ................................................. 192-3 .............................................................. 02-4 ............................................................ 152-5 ............................................................ 202-6 ............................................................ 172-7 ............................................................ 192-8 .............................................................. 02-9 2-12 ............................................... 172-12A/2-12B............................................. 202-13 .......................................................... 172-14 .......................................................... 222-15 ............................................................ 92-16 .......................................................... 192-17 .......................................................... 202-18 .......................................................... 192-19 .......................................................... 232-20 .......................................................... 202-20A/2-20B............................................. 192-21 .......................................................... 152-22 .......................................................... 132-23/2-24 .................................................... 03-1 3-2 ................................................. 19

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BHT-412-FM-4 FAA APPROVED

LOG OF APPROVED REVISIONS

Temporary ......................... 8 AUG 97Revision 1 .......................... 18 DEC 97Canceled .......................... 05 SEP 00

NOTICE

This Temporary Revision has been cancelled. Subject datahas been incorporated in BHT-412-FM-4 at Revision 21.Remove and discard all Temporary pages dated 8 August1997 from this manual including these canceled pages.

APPROVED: SEP 52000

MANAGER

ROTORRAFT CERTIFICATION OFFICEFEDERAL AVIATION ADMINISTRATIONFT. WORTH, TX 76193-0170

TEMPORARY REVISION - 8 AUG 97B CANCELED-5 SEP 2000

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LOG OF APPROVED REVISIONS

Temporary ...................... .8 AUG 97 Revision 1 .......................... 18 DEC 97

FAA APPROVED

MANAGER

ROTORCRAFT CERTIFICATION OFFICE FEDERAL AVIATION ADMINISTRATION FT. WORTH, TX 76193-0170

TEMPORARY REVISION 8 AUG 97 B REVISION 1 - 18 DEC 97

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LOG OF FAA APPROVED REVISIONS

Original ....................... 0.................... 23 JUN 94 Revision......................13.................. 14 NOV 97Revision ...................... 1.................... 23 DEC 94 Revision......................14.................. 14 NOV 97Revision ...................... 2.................... 06 JUN 95 Revision......................15 .................. 26 MAR 98Revision ...................... 3.................... 23 JUN 95 Revision......................16.................. 21 APR 98Revision ...................... 4....................29 AUG 95 Revision...................... 17.................. 14 MAY 98Revision ...................... 5.................... 26 OCT 95 Revision......................18.................. 28 OCT 98Revision ...................... 6.................... 23 FEB 96 Revision...................... 19.................. 20 DEC 99Revision ...................... 7....................22 AUG 96 Revision......................20.................. 26 MAY 00Revision ...................... 8.................... 10 SEP 96 Revision......................21 ................... 05 SEP 00Revision ...................... 9................... 12 MAR 97 Revision......................22 ................... 11 JUN 01Revision ..................... 10.................. 12 MAR 97 Revision.....................23.................. 23 MAY 02Revision ..................... 11....................23 JUL 97 Revision......................24.................. 05 NOV 02Revision ..................... 12...................08 AUG 97

APPROVED: DATE: NOV 5 2002

MANAGER

ROTORCRAFT CERTIFICATION OFFICEFEDERAL AVIATION ADMINISTRATIONFT. WORTH, TX 76193-0170

05 NOV2002 Rev. 24 C/D

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ORGANIZATION

The Rotorcraft Flight Manual is dividedinto five sections as follows:

Section 1 - LIMITATIONS

Section 2

Section 3

Section 4

BHT-412-FM-4FAA APPROVED

GENERAL INFORMATION

- NORMALPROCEDURES

- EMERGENCY ANDMALFUNCTIONPROCEDURES

- PERFORMANCE

Section 5 - WEIGHT ANDBALANCE

Appendix A - OPTIONALEQUIPMENT

Sections 1 through 4 contain the FAAapproved data necessary to operate thebasic helicopter in a safe and efficientmanner. Section 5 contains Weight andBalance data. Appendix A contains thelisting of approved Supplements foroptional equipment which shall be used inconjunction with the basic Flight Manualwhen respective optional equipment kitsare installed.

The Manufacturer's Data manual, (BHT-412-MD-4) contains additional informationto be used in conjunction with the FlightManual.

TERMINOLOGY

WARNINGS, CAUTIONS, AND NOTES AREUSED THROUGHOUT THIS MANUAL TOEMPHASIZE IMPORTANT AND CRITICALINSTRUCTIONS AS FOLLOWS:

AN OPERATING PROCEDURE,PRACTICE, ETC., WHICH, IF NOTCORRECTLY FOLLOWED, COULDRESULT IN PERSONAL INJURYOR LOSS OF LIFE.

. .................

CAUTION

AN OPERATING PROCEDURE,PRACTICE, ETC., WHICH, IF NOTSTRICTLY OBSERVED, COULDRESULT IN DAMAGE TO ORDESTRUCTION OF EQUIPMENT.

NOTE

AN OPERATING PROCEDURE,CONDITION, ETC., WHICH ISESSENTIAL TO HIGHLIGHT.

USE OF PROCEDURAL WORDS

The concept of procedural word usage andintended meaning which has been adheredto in preparing this manual is as follows:

"Shall" has been used only whenapplication of a procedure is mandatory.

"Should" has been used only whenapplication of a procedure isrecommended.

"May" and "need not" have been used onlywhen application of a procedure isoptional.

"Will" has been used only to indicatefuturity, never to indicate a mandatoryprocedure.

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BHT-412-FM-4

ABBREVIATIONS

Abbreviations used through out this manual aredefined as follows:

AC

ADD

ADF

ADI

AFCS

AHRS

ALTN

AOG

API

AP1/AP2

ATT or ATTD

AUX

BAT

BLWR

C

CDI

I CCP

CG

CPL

CPLT

CRS

CYC CTR

- Alternating Current

- Air Data Display

- Automatic Direction Finder

- Attitude Director Indicator

- Automatic Flight ControlSystem

- Attitude Heading andReference System

- Alternate

- Aircraft on Ground

- Actuator Position Indicator

- Autopilot 1/ Autopilot 2

- Attitude

-Auxiliary

- Battery

- Blower

- Celsius

- Course Deviation Indicator

- Compass Control Panel

- Center of Gravity

-Couple

- Copilot

- Course

- Cyclic Center

DC

DCPL

DECEL

DECR

DEG

DH

DET

EEPROM

EMERG

ENC

F

FTFUELTRANSGENGOV

HDHDGHp

HSI

HYDRIAS

ICS

IFRIGEIMC

INCRINTCON

- Direct Current

-Decouple

- Deceleration

- Decrease

- Degrees

-Decision Height

- Detector

- Electrically ErasableProgramable Read OnlyMemory

-Emergency

- Encoding

- Fahrenheit

- Force Trim or foot/feet- Fuel Transfer- Generator- Governor- Density Altitude

- Heading- Pressure Altitude

- Horizontal Situation Indicator

- Hydraulic- Indicated Airspeed

- Intercommunication System- Instrument Flight Rules- In Ground Effect- Instrument MeteorologicalConditions- Increase- Interconnect

II Rev. 19

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FAA APPROVED BHT-412-FM-4

INV

ITT

IVSI

KCAS

KIAS

LE

LF

LH

LRC

LT

MAG

MAX END

MCP

N,

Nil

NAV

NON-ESNTL

NORM

NR

OAT

OEI

OGE

OVRD

PART SEP

- Inverter

- InterturbineTemperature

- Instantaneous VerticalSpeed Indicator

- Knots CalibratedAirspeed

- Knots IndicatedAirspeed

- Level

- Low Frequency

- Left Hand

- Long Range Cruise

- Light

- Magnetic

- Maximum Endurance

- Maximum ContinuousPower

- Gas Producer RPM

- Power Turbine RPM

- Navigation

- Non-essential

- Normal

- Rotor RPM

- Outside AirTemperature

- One EngineInoperative

- Out of Ground Effect

- Override

- Particle Separator

PNL

PWR

PSI

RAD ALT

REL

RH

SAS

SBY ATT

SL

STBY

SYNC

SYS

VAC

VDC

VEL HLD

VFR

VG

VLF

VMC

VNE

VTOCS

XPDR

XFEED

XMSN

- Panel

- Power

- Pounds per SquareInch

- Radar Altimeter

- Release

- Right Hand

- StabilityAugmentation System

- Standby Attitude

- Sea Level

- Standby

- Synchronize

- System

- Volts AlternatingCurrent

- Volts Direct Current

- Velocity Hold

- Visual Flight Rules

- Vertical Gyro

- Very Low Frequency

- Visual MeteorologicalConditions

- Never Exceed Speed

- Takeoff ClimboutSpeed

- Transponder

- Crossfeed

- Transmission

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Section 1

TABLE OF CONTENTSPage

Subject Paragraph Number

INTRODUCTION ........................................................................ 1-1.................... 1-3BASIS OF CERTIFICATION ........................................ ......... 1-2.................... 1-3TYPES OF OPERATION ............................................................. 1-3.................... 1-3

PASSENGER ............... ......................... 1-3-A .............. 1-3CARGO ................................................................................... 1-3-B .............. 1-3

FLIGHT CREW ......................................................................... 1-4.................... 1-4CONFIGURATION....................................................................... 1-5.................... 1-4

REQUIRED EQUIPMENT........................................................ 1-5-A .............. 1-4OPTIONAL EQUIPMENT ........................................................ 1-5-B .............. 1-4DOORS OPEN/REMOVED ........................................ 1-5-C.............. 1-4A/1-4B

WEIGHT AND CENTER OF GRAVITY ....................................... 1-6.................... 1-4A/1-4BWEIGHT................................................................................... 1-6-A.............. 1-4A/1-4BCENTER OF GRAVITY .......................................................... 1-6-B.............. 1-4A/1-4B

AIRSPEED................................................................................... 1-7.................... 1-5ALTITUDE................................................................................... 1-8.................... 1-5MANEUVERING.......................................................................... 1-9.................... 1-6

PROHIBITED MANUEVERS................................................. 1-9-A .............. 1-6CLIMB AND DESCENT........................................................... 1-9-B .............. 1-6SLOPE LANDING ........................................ ......... 1-9-C .............. 1-6

HEIGHT - VELOCITY ........................................ 1-10.................. 1-6AMBIENT TEMPERATURES...................................................... 1-11.................. 1-6ELECTRICAL.............................................................................. 1-12.................. 1-6

BATTERY................................................................................ 1-12-A ......... 1-6GENERATOR ............... ...................... ... 1-12-B ............ 1-6STARTER .............................................................................. 1-12-C ............ 1-7GROUND POWER UNIT ........................................................ 1-12-D ............ 1-7

POWER PLANT .......................................................................... 1-13.................. 1-7GAS PRODUCER RPM........................................................... 1-13-A ............ 1-7POWER TURBINE RPM (Nl) ................................................. 1-13-B ............ 1-7INTERTURBINE TEMPERATURE .......................................... 1-13-C ............ 1-8ENGINE TORQUE................................................................... 1-13-D ............ 1-8FUEL PRESSURE................................................................... 1-13-E ............ 1-8ENGINE OIL PRESSURE ................................................. 1-13-F ............ 1-8ENGINE OIL TEMPERATURE................................................ 1-13-G ............ 1-9COMBINING GEARBOX OIL PRESSURE ............................. 1-13-H ............ 1-9COMBINING GEARBOX OIL TEMPERATURE ..................... 1-13-J ............. 1-9

TRANSMISSION ........................................ ......... 1-14.................. 1-9TRANSMISSION OIL PRESSURE .......................................... 1-14-A............ 1-9TRANSMISSION OIL TEMPERATURE .................................. 1-14-B ............ 1-9MAST TORQUE ........................................ ...... 1-14-C ............ 1-10

Rev.18 -11

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TABLE OF CONTENTS (CONT)Page

Subject Paragraph Number

ROTOR....................................................................................... 1-15 ........... 1-10ROTOR RPM - POWER ON ................................................ 1-15-A ............ 1-10ROTOR RPM - POWER OFF .............................................. 1-15-B ............ 1-10ROTOR RPM - GROUND OPERATION ............................... 1-15-C ............ 1-10

HYDRAULIC................................................................................ 1-1 ................ 1-10HYDRAULIC PRESSURE....................................................... 1-16-A ............ 1-11HYDRAULIC TEMPERATURE ............................................... 1-16-B ............ 1-11

FUEL AND OIL ......................................... 1-17 ................. 1-11FUEL ....................................................................................... 1-17-A ............ 1-11OIL....................................................................................... 1-17-B ............ 1-11

ROTOR BRAKE ............................................. 1-18................ 1-11LANDING GEAR ......................................................................... 1-19................ 1-12INSTRUMENT MARKINGS AND PLACARDS........................... 1-20................ 1-12HEATER...................................................................................... 1-21 ................ 1-12HOIST PENALTY REGION ......................................................... 1-22................ 1-12AHRS ALIGNMENT .................................................................... 1-23................ 1-12

LIST OF FIGURESFigure Page

Title Number Number

Gross weight center of gravity charts ..................................... 1-1 .................. 1-13Weight-altitude-temperature limitations for takeoff,landing, and in-ground-effect maneuvers ............................... 1-2.................. 1-15Maximum speed - sideward and rearward flight,crosswind and tallwind at a hover ........................................... 1-3.................. 1-16Height-velocity diagram (OEI) ................................................ 1-4.................. 1-17Instrument markings ................................................................. 1-5.................. 1-18Placards and decals.................................................................. 1-6.................. 1-23Hoist C.G. envelope................................................................... 1-7......... 1-......... 1-24

1-2 Rev. 19

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!ection 1*IMITATION!

1-1. INTRODUCTION

Compliance with limitations in this section isrequired by appropriate operating rules.

1-2. BASIS OF CERTIFICATION

This helicopter is certified under FAR Part 29,Category A and B. Refer to BHT-412-FMS-62.4for Category A Operations.

1-3. TYPES OF OPERATION

Basic configured helicopter is approved as afifteen-place helicopter and is certified foroperation under day or night VFR and IFRnonicing conditions.

1-3-A. PASSENGER

NOTERefer to Section 5 for loading tablest o b e u s e d i n w e i g h t / C Gcomputations.

Outboard fac ing seats shou ld no t beoccupied unless at least four forward or aftfacing passenger seats are occupied.

Above loading does not apply if cargo or acombination of cargo and passengers arebeing transported. It shall then be pilot

responsibility to ensure helicopter is properlyloaded so entire flight is conducted withinlimits of gross weight center of gravity charts(Figure 1-1).

1-3-B. CARGO

Maximum allowable deck loading for cargo is100 pounds per square foot (4.9 kg/100sq cm). Deck mounted cargo tiedown fittingsare provided and have an airframe structuralcapacity of 1250 pounds (567.0 kilograms)vertical and 500 pounds (226.8 kilograms)hor izon ta l per f i t t ing . P rov is ions forinstallation of cargo tiedown fittings areincorporated in aft cabin bulkhead andtransmission support structure and have anairframe structural capacity of 1250 pounds(567.0 kilograms) at 90 degrees to bulkheadand 500 pounds (226.8 kilograms) in anydirection parallel to bulkhead. Cargo shall besecured by an approved restraint method thatwill not impede access to cargo in event ofemergency.

NOTERefer to the applicable operatingrules for internal cargo operations.

Baggage compartment has a load limit of 400pounds (181 kilograms), not to exceed 100pounds per square foot (4.9 kg/100 sq cm).Refer to Section 5.

05 NOV 2002 Rev. 24 1-3

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1-4. FLIGHT CREW

The minimum flight crew consists of one pilotwho shall operate helicopter from right crewseat. Refer to Section 5. for minimum crewstation weight.

The lef t crew seat may be used for anadditional pilot when approved dual controlsare installed.

1-5. CONFIGURATION

1-5-A. REQUIRED EQUIPMENT

1-5-A-1. AFCS

AFCS shall be disengaged or operated in SASmode during prolonged ground operation,except as required for AFCS check.

AHRS shall be certified only on helicoptersS/N 36248 and subsequent.

1-5-A-2. REQUIRED EQUIPMENT IFR

Both autopilots, AP 1 and AP 2, shall be engaged in ATT mode during flight.

Heated pitot-static system.

Pilot windshield wiper.

Two VHF communications radios.

Two navigation receivers with auxiliary equipment appropriate to intended IFR route of flight.

DME equipment.

ATC transponder.

Marker beacon receiver.

3 inch standby attitude indicator.

Pilot IVSI.

Force trim.

Roof window blackout curtains.

EMERGENCY COMM panel, (if installed) (single pilot only).

Digital AFCS preflight test (level 1 minimum)shall be accomplished prior to first flight ofthe day or before planned flight into IMC.

1-5-B. OPTIONAL EQUIPMENT

Refer to appropr ia te F l ight ManualSupplement(s) for additional limitations,procedures, and performance data withoptional equipment installed. See Appendix A.

When a CVR is required by the operatingru les , on ly headse ts wi th a dynamicmicrophone are approved. CVR operation withother types of microphones requires FAAapproval.

1-4 Rev. 23 23 MAY 2002

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1-5-C. DOORS OPEN/REMOVED

Helicopter may be flown with doors open orremoved only with Bell Standard Interior (412-705-501) or Bell Deluxe Interior (412-705-500)installed. Flight operation is approved forfollowing alternative configurations duringVFR conditions only:

Symmetrical configurations:

Both crew doors removed.

Both sliding doors locked open orremoved with both hinged panelsinstalled or removed.

Asymmetrical configurations:

Cargo dooors can be opened or closedasymmetrically, to a locked position, withfollowing restrictions:

1. Two way communications betweenpilot and cabin crew member.

2. All crew members and passengers aresecured with an approved restraint.

NOTEOpening or removing doors shiftshelicopter center of gravity andreduces VNE. Refer to Section 5 and toAirspeed limitations.

1-6. WEIGHT AND CENTER OFGRAVITY

1-6-A. WEIGHT

Maximum gross weight for takeoff andlanding is 11,900 pounds (5398 kilograms).

Refer to Weight-Altitude-TemperatureLimitations chart (figure 1-2) for maximumallowable weight for takeoff, landing, and IGEhover operation.

Minimum gross weight for flight is 6400pounds (2903 kilograms).

Minimum combined crew weight at fuselagestation 47.0 is 170 pounds (77.1 kilograms).

1-6-B. CENTER OF GRAVITY

1-6-B-1. LONGITUDINAL CENTER OFGRAVITY

Longitudinal center of gravity limits vary fromstation 130 to 144, depending on grossweight. Refer to Gross weight center ofgravity charts (figure 1-1).

1-6-B-2. LATERAL CENTER OF GRAVITY

Lateral center of gravity limits are 4.5 Inches(114.3 millimeters) left and right of fuselagecenterline for all gross weights.

Rev. 18 1-4A /1-4B

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1-7. AIRSPEED VNE with doors symmetrically open orremoved is 100 KIAS with Bell Helicopter

Minimum IFR airspeed is 60 KIAS. installed Blanket Interior (412-705-501) orDeluxe Interior (412-705-500).

Basic VNE is 140 KIAS from sea level to 3000feet density altitude at all gross weights. VNE Maximum allowable airspeed for sideward ordecreases for ambient conditions in rearward flight at or below 3000 feet HD is 35accordance with airspeed limitations placard knots. See figure 1-3 for additional limitations.(paragraph 1-20).

(paragraph 1- 20).Maximum allowable tailwind or crosswindAirspeed shall not exceed 105 KIAS (or speeds for hover operations at or below 3000placarded VNE, if less) when operating above feet HD is 35 knots. See figure 1-3 for81% mast torque. additional limitations.

VNE with only one autopilot engaged is 115 Refer to Critical relative wind azimuthsKIAS (or placarded VNE, if less). If both diagram in Section 4.autopilots are disengaged, basic VNE applies. 1-8. ALTITUDE

VNE for steady state autorotation is: NOTENOTE105 KIAS at or below 10,000 feet (3048 Refer to applicable operating rules formeters) pressure altitude; high altitude oxygen requirements.

80 KIAS above 10,000 feet (3048 meters) Maximum operating pressure altitude ispressure altitude. 20,000 feet (6096 meters).

Maximum density altitude for takeoff, landing,and in-ground-effect maneuvers is 14,000 feet(4267 meters). Refer to Weight-Altitude-

VNE with cargo doors opened asymmetrically Temperature Limitations chart (figure 1-2).is 80 KIAS.

Above 15,000 feet (4,572 meters) pressureVNE with cargo doors in transit or in an altitude, restart shall be attempted in manualunlocked position Is 60 KIAS. fuel control mode only.

VNE with doors symmetrically open orremoved is 60 KIAS with Bell Helicopterinstalled energy attenuating passenger seats(412-706-002).

NOTEAsymmetric door configuration is notauthorized with energy attenuatingseats installed.

Rev. 20 1-5

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Below 15,000 feet (4,572 meters) pressure Minimum ambient temperature for operationaltitude, restart may be attempted In either at all altitudes is -40C (-40F).manual or automatic fuel control mode.

1-9. MANEUVERINGNOTE

1-9-A. PROHIBITED MANEUVERS Refer to paragraph 1-13-F, EngineOil Pressure.

Aerobatic maneuvers are prohibited.

1-9-B. CLIMB AND DESCENT 1-12. ELECTRICALMaximum IFR rate of climb or descent is 1000 1-12-A. BATTERYfeet per minute. Maximum battery case temperature is 54.5C

(130F), as Indicated by illumination ofMaximum IFR approach slope is 5 degrees. BATTERY TEMP warning light.

1-9-C. SLOPE LANDING WARNINGWARNINGSlope landings are limited to side slopes notto exceed 10 degrees. BATTERY SHALL NOT BE USED

FOR ENGINE START AFTER1-10. HEIGHT-VELOCITY ILLUMINATION OF BATTERY

TEMP LIGHT. BATTERY SHALLThe height-velocity limitations are critical in BE REMOVED AND SERVICED INthe event of single engine failure during ACCORDANCE WITH MANUFAC-takeoff, landing, or other operation near the TURER'S INSTRUCTIONS PRIORsurface (figure 1-4). The AVOID area of the TO RETURN TO SERVICE.Height-Velocity diagram defines thecombinations of airspeed and height above Minimum ambient temperature for batteryground from which a safe single engine start when battery and helicopter have beenlanding on a smooth, level, firm surface cold soaked is -25C (-13F).cannot be assured.

1-12-B. GENERATORThe H-V diagram Is valid only when theWeight-Altitude-Temperature limitations are Continuous operation 0 to 75 ampsnot exceeded (figure 1-2). The diagram does Caution 75 tonot define the conditions which assure Caution 75 to 150 ampscontinued flight following an engine failurenor the conditions from which a safe power NOTEoff landing can be made. During OEI operation electrical

loads may have to be reduced to1-11. AMBIENT TEMPERA- remain below maximumTURES continuous limits.

The maximum sea level ambient airtemperature for operation is +51.7C (+125F)and decreases with pressure altitude at thestandard lapse rate of 2C (3.6F)/1000 feet(305 meters) to 20.000 feet (6096 meters).

1-6 Rev. 22 11 JUN 2001

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FAA APPROVED

Maximumcontinuous

BHT-412-FM-4

helicopter logbook detailing the extent ofoperation In excess of twin engine takeoffpower limits. This does not apply toapproved ITT limits for starting.

150 amps (each)

NOTE

Ammeter needle may deflect fullscale momentarily duringgenerator assisted start of secondengine.

1-12-C. STARTER

1-13-A. GAS PRODUCER RPM(N1)

1-13-A-1. TWIN ENGINEOPERATION

I

Starter energizing times shall be limited asfollows:

30 seconds ON

60 seconds OFF

30 seconds ON

5 minutes OFF

30 seconds ON

15 minutes OFF

1-12-D. GROUND POWER UNIT

28 vdc ground power units for startingshall be limited to 1000 amps maximum.

1-13. POWER PLANT

Pratt and Whitney Aircraft of Canada, Ltd.PT6T-3D.

NOTE

Operation in 2'/2 minute orContinuous OEI range is intendedfor emergency use only, when oneengine becomes inoperative dueto an actual malfunction.

Anytime an engine is operated in an OEIrange, an entry shall be made in the

Continuous operation

Maximum continuous

Maximum for takeoff

61 to 103.1%

103.1%

103.1%

1-13-A-2. ONE ENGINEINOPERATIVE (OEI)

Continuous OEI

2 1/2 minute OEI

Maximum OEI

103.7

103.7 to 109.2%

109.2%

1-13-B. POWER TURBINE RPM(Ni.)

Minimum in cruise

Minimum for hover,takeoff, and climb

Maximum continuous

Operation with ENGtorque at or below 30%

Maximum with ENGtorque at or below 30%

97%

100%

100%

100 to 104.5%

104.5%

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1-13-C. INTERTURBINETEMPERATURE

NOTEEither ITT gage shall be installedin pairs.

1-13-C-1. TWIN ENGINEOPERATION

GAGE PN 212-075-067-115Continuous 300 to 810 CMaximum continuous 810 CMaximum transient (5seconds maximumabove 810) 925 C

Maximum for starting (2seconds maximumabove 960) 1090 C

2 1/2 minute OEIMaximum OEI

820 to 940 C940 C

1-13-D. ENGINE TORQUEONE ENGINE INOPERATIVE (OEI)

Continuous OEI

Maximum ContinuousOEI21/2 minute OEIMaximum OEI

5 to 73.2%

73.2%73.2 to 81%81%

1-13-E. FUEL PRESSURE

MinimumContinuous operationMaximum

4 psi4 to 35 psi35 psi

GAGE PN 212-075-067-119Continuous 300 to 810 CMaximum continuous 810 C

Maximum transient (5seconds maximumabove 810) 940 C

Maximum for starting (2seconds maximumabove 960) 1090 C

CAUTION

INTENTIONAL USE OF ITT ABOVE810C IS PROHIBITED DURINGNORMAL OPERATIONS EXCEPTDURING START.

1-13-C-2. ONE ENGINEINOPERATIVE (OEI)

GAGE PN 212-075-067-115

Maximum continuousOEI 820 C

2 1/2 minute OEI 820 to 925 CMaximum OEI 925 C

GAGE PN 212-075-067-119

Maximum continuousOEI 820 C

1-13-F. ENGINE OIL PRESSURE

NOTEDuring extremely cold ambienttemperatures, Idle rpm will behigh and the ENGINE OILpressure may exceed maximumlimits for up to two minutes afterstarting.

NOTEEither Engine Oil Pressure/Temperature gage shall beinstalled in pairs. Refer toparagraph 1-11, AMBIENT AIRTEMPERATURE.

GAGE PN 209-070-262-113

Minimum for flight Idle 40 psiOperation below 79% N,rpm 40 to 90 psiContinuous operation 90 to 115 psiMaximum 115 psi

GAGE PN 209-070-262-109

Minimum for flight idle 40 psiOperation below 79% N,rpm 40 to 80 psiContinuous operation 80 to 115 psiMaximum 115 psi

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1-13-G. ENGINE OILTEMPERATURE

Continuous operation 0 to 115 C

Maximum for MIL-L-7808oil

Minimum 0 C Maximum for MIL-L-23699oil

Maximum for DOD-L-85734 oil

115 C

120 C

120 CContinuous operation 0 to 115 C



Maximum for DOD-L-85734 oil

115 C1-14. TRANSMISSION

120 C1-14-A. TRANSMISSION OILPRESSURE

120 C

1-13-H. COMBINING GEARBOX OILPRESSURE

NOTEDuring extremely cold ambienttemperatures, idle rpm will behigh and the XMSN OIL pressuremay exceed maximum limits forup to two minutes after starting..

NOTE

During extremely cold ambienttemperatures,GEAR BOX OILpressure may exceed maximumlimits for up to two minutes afterstarting.

Minimum for idle 30 psi

Idle range 30 to 40 psi

Continuous operation 40 to 70 psi

Maximum 70 psi

Minimum for idle

Operation below 94%N11 rpm

40 psi

40 to 60 psi

1-14-B. TRANSMISSION OILTEMPERATURE

Continuous operation 15 to 110 CContinuous operation 60 to 80 psi

Maximum 110 CMaximum 80 psi

1-13-J. COMBINING GEARBOX OILTEMPERATURE

Minimum 0 C

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1-14-C. MAST TORQUE

1-14-C-1. TWIN ENGINEOPERATION

Maximum continuous 81%

Takeoff range (5 minutesmaximum) 81 to

Maximum continuous 100%

Operation with ENGtorque at or below 30% 100 to 104.5%

Maximum with ENGtorque at or below 30% 104.5%

100%

100%Maximum

TAKEOFF POWER SHALL NOT BEUSED ABOVE 105 KIAS.

CAUTION

WHEN OPERATING NEAR THEMAXIMUM MAST TORQUE LIMIT,INADVERTENT OVERTORQUEMAY OCCUR DURINGMANEUVERING FLIGHTCONDITIONS INVOLVING TURNSAND/OR NOSE DOWN ATTITUDECHANGES. DECREASE POWERTO 90% MAST TORQUE PRIOR TOMANEUVERING HELICOPTER.

Intentional use of mast torque over 100%is prohibited.

1-15-B. ROTOR RPM - POWEROFF

Minimum for autorotationwith gross weight below8000 pounds (3629 kg) 80%

Power off operation withgross weight below 8000pounds (3629 kg) 80 to 104.5%

Minimum for autorotationwith gross weight at orabove 8000 pounds (3629kg) 91%

Maximum 104.5%

1-15-C. ROTOR RPM - GROUNDOPERATION

Minimum

Minimum with stickcentering indicatorsystem inoperative

Transient (avoid steadystate operations)

77%

97%

26 to 77%

1-15. ROTOR 1-16. HYDRAULIC

1-15-A. ROTOR RPM - POWERON

Minimum 97%

Continuous operation 97 to 100%

NOTERefer to BHT-412-MD-4 forapproved fluids and vendors.

Hydraulic fluid type MIL-H-5606 (NATO H-515) shall be used at all ambienttemperatures.

Both hydraulic systems shall be operativeprior to takeoff.

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WARNING

THE HELICOPTER IS NOTCONTROLLABLE WITH BOTHHYDRAULIC BOOST SYSTEMSINOPERATIVE.

1-16-A. HYDRAULIC PRESSURE

1-16-B. HYDRAULIC TEMPERATURE

1-17. FUEL AND OIL

NOTE

Refer to BHT-412-MD-4 for lists ofapproved fuels, oils, capacities, andvendors.

1-17-A. FUEL

Fuel conforming to ASTM D-1655 Type B,NATO F-40, or MIL-T-5624 Grade JP-4 maybe used at all ambient temperatures.

Fuel conforming to ASTM D-1655 Type Aor A-1, NATO F-44, MIL-T-5624 Grade JP-5,NATO F-34, or MIL-T-83133 Grade JP-8,limited to ambient temperatures above-30C (-22F).

1-17-B. OIL

1-17-B-1. ENGINE AND COMBINING GEARBOX

Oil conforming to PWA Specification No.521 Type I and MIL-L-7808 (NATO 0-148)may be used at all ambient temperatures.Oil conforming to PWA Specification No.521 Type Il and MIL-L-23699 (NATO 0-156),or DOD-L-85734AS limited to ambienttemperatures above -40C (-40F).

1-17-B-2. TRANSMISSION, INTERMEDIATE AND TAIL ROTOR GEARBOX

Oil conforming to DOD-L-85734AS (TurbineOil 555) is the only approved oil for use inthe transmission and gearboxes.

1-18. ROTOR BRAKE

Engine starts with rotor brake engaged areprohibited. Rotor brake application is limitedto ground operation and shall not be applieduntil both engines are shut down and rotor rpmhas decreased to 40% NR or below.

Minimum 600 psi

Caution 600 to 900 psi

Continuous operation 900 to 1100 psi

Maximum 1100 psi

Maximum 88C

23 MAY 2002 Rev. 23 1-11

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1-19. LANDING GEAR for Bell Helicopter approved Hoists.

No Flight Manual Limitations.WARNING

1-20. INSTRUMENT MARKINGSAND PLACARDS THIS PENALTY REGION IS VALID FOR

ALL HOIST INSTALLATIONS.NOTE

Illustrations shown in figure 1-5 are OPERATION IN PENALTY REGIONartist representations and may or may AFFECTS AIRWORTHINESSnot depict actual approved instruments LIMITATIONS OF ROTORdue to printing limitations. Instrument COMPONENTS (REFER TO BHT-412-operating ranges and limits shall agree MM).with those presented in this section. ALIGNMENT1-23. AHRS ALIGNMENT

Refer to Figure 1-5 for instrument rangemarkings and Figure 1-6 for placards and To perform in-flight/shipboard AHRSdecals. alignment, the following conditions must be

met:

1-21. HEATER

Heater shall not be operated when OAT isabove 21C (69.8F). Pitch Less than 10

1-22. HOIST PENALTY REGION Roll Less than 5Yaw Rate Less than 1/sec

Pilot shall know C.G. at time of hoist operationto determine if C.G. is within penalty region of Lateral and Less than 0.05gfigure 1-7, Hoist C.G. envelope. Logitudinal

Each hoist operation performed is defined as Accelerationan extension and retraction of hoist cablewhile hovering with any weight attached. For a minimum of 30 seconds for attitude and

heading to become valid.Refer to BHT-412-FMS-7 or BHT-412-FMS-26

1-12 Rev. 19

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ENGLISH UNITS

BHT-412EP-FM-1-1-1

Figure 1-1. Gross weight center of gravity charts (Sheet 1 of 2).

Rev. 5 1-13

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3432 359400 5398-

5200 /

5000-

-- 4800

4400

-4200 3302

4000 3992 FOWARD LIMIT AFT LIMIT

3800

3600 -

3400I

3200

3000


MINIMUM WEIGHT 3658

3250 3300 3350 3400 3450 3500 3550 3600 650

LONGITUDINAL C.G. FUSELAGESTA.-mm

METRIC UNITS

BHT-412EP-FM-1-1-2

Figure 1-1. Gross weight center of gravity charts (Sheet 2 of 2).

1-14 Rev. 5

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NOTE: ALLOWABLE GROSS WEIGHTS OBTAINED FROM THIS CHART MAY EXCEEDCONTINUOUS HOVER CAPABILITY UNDER CERTAIN AMBIENT CONDITIONS.REFER TO HOVER CEILING CHARTS IN SECTION 4.

-40-20 0 20 40 60OAT- C

9 10 11 12 LBX1000

4.0 4.5 5.0 5.4 kg x 1000GROSS WEIGHT

BHT-412EP-FM-1-2

Figure 1-2. Weight-altitude-temperature limitations for takeoff, landing, and in-ground-effect maneuvers.

Rev. 5 1-15

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NOTE:

OGE CRITICAL RELATIVE WIND AZIMUTH IGE CRITICAL RELATIVE WIND AZIMUTH

14,000 FT. DENSITY ALTITUDE

Figure 1-3. Maximum speed - sideward and rearward flight, crosswind and tailwind at ahover.

Rev. 5

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HEIGHT - VELOCITY DIAGRAM

FOR SMOOTH. LEVEL. FIRM SURFACES

400 120AND ABOVE NOTE: HELICOPTER CONFIGURATION AND ABOVE

SHALL COMPLY WITH THE WEIGHT .375 380 ALTITUDE TEMPERATURE LIMITS -114.3

AS PRESENTED IN FIGURE 1-2FOR360 HEIGHT - VELOCITY DIAGRAM TO BE -110

VALID.

340

320 -100

300

280

260 80

220

200 60

180

160 0

14040

120

10 30

80-20

40 10

0 10 20 30 40 VNE

INDICATED AIRSPEED - KNOTS

BHT-412EP-FM-1-4

Figure 1-4. Height-velocity diagram (OEI).

Rev. 20 1-17

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I Figure 1-5. Instrument markings (Sheet 1 of 5) 1-18 Rev. 5

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412EP-F-1-5-2

Figure 1-5. Instrument markings (Sheet 2 of 5) I

Rev. 6 1-19

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412EP-F-1-5-4

Figure 1-5. Instrument markings (Sheet 4 of 5) I

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........:,.:':.

Oo

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o

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Section 2TABLE OF CONTENTS

PageNumberSubject Paragraph

INTRODUCTION .........................................................................FLIGHT PLANNING ....................................................................

TAKEOFF AND LANDING ......................................................W EIGHT AND BALANCE .......................................................

PREFLIGHT CHECK...................................................................BEFORE EXTERIOR CHECK.................................................EXTERIOR CHECK.................................................................

INTERIOR AND PRESTART CHECK.........................................ENGINE START ..........................................................................

ENGINE 1 START ...................................................................ENGINE 2 START ...................................................................POST START ..........................................................................ENGINE FAILS TO START.....................................................DRY M OTORING RUN............................................................COLD W EATHER START.......................................................

SYSTEM S CHECK......................................................................STICK CENTERING INDICATOR CHECK.............................FORCE TRIM CHECK.............................................................PRELIMINARY HYDRAULIC CHECK ....................................ENGINE FUEL CONTROL CHECK........................................GOVERNOR CHECK ..............................................................FUEL CROSSFEED AND INTERCONNECT VALVE CHECKELECTRICAL SYSTEMS CHECK..........................................HYDRAULIC SYSTEMS CHECK............................................AFCS CHECK .........................................................................AHRS CHECK (S/N 36248 AND SUB) ...................................CABIN HEATER CHECK........................................................

BEFORE TAKEOFF....................................................................POWER ASSURANCE CHECK..............................................PROLONGED GROUND OPERATION ..................................OPERATION IN OR NEAR MAGNETIC DISTURBANCES(AHRS EQUIPPED SHIPS - S/N 36248 AND SUB).............

TAKEOFF....................................................................................IN-FLIGHT OPERATIONS ..........................................................

MANEUVERING WITH AFCS IN SAS MODE ........................MANEUVERING WITH AFCS IN ATT MODE.........................

DESCENT AND LANDING..........................................................ENGINE SHUTDOW N.................................................................

2-1..................2-2..................2-2-A ..............2-2-B ..............2-3..................2-3-A ..............2-3-B ..............2-4..................2-5..................2-5-A ..............2-5-B ..............2-5-C ..............2-5-D ..............2-5-E ..............2-5-F ..............2-6 ..................2-6-A ..............2-6-B ..............2-6-C ..............2-6-D ..............2-6-E ..............2-6-F ..............2-6-G ..............2-6-H ..............2-6-J...............2-6-K ..............2-6-L ..............2-7..................2-7-A ..............2-7-B ..............

2-7-C ..............2-8 ..................2-9..................2-9-A ..............2-9-B ..............2-10................2-11................

2-32-32-32-32-42-42-42-72-92-92-112-112-122-12

2-12A/2-12B2-132-132-132-132-142-142-142-152-152-162-172-182-182-192-19

2-192-192-202-202-202-202-21

Rev. 19 2-1

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POSTFLIGHT CHECK ................................................................

LIST OF FIGURES

2-12................ 2-22

FigureNumber

PageNumberTitle

Preflight check sequence ..................................................... 2-1................ 2-23/2-24

1 2-2 Rev. 19

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Section 22-1. INTRODUCTION

This section contains instructions andprocedures for operating the helicopterfrom the planning stage, through actualflight conditions, to securing thehelicopter after landing.

Normal and standard conditions areassumed in these procedures. Pertinentdata in other sections is referenced whenapplicable.

The instructions and procedures containedherein are written for the purpose ofstandardization and are not applicable toall situations.

The minimum, normal, maximum, andcautionary operation ranges for thehelicopter and its subsystems areindicated by instrument markings andplacards.

Anytime an operating limitation isexceeded, an appropriate entry shall bemade in the helicopter logbook. The entryshall state which limit was exceeded, theduration of time, the extreme valueattained, and any additional informationessential in determining the maintenanceaction required.

These instrument markings and placardsrepresent careful aerodynamiccalculations that are substantiated byflight test data.

2-2. FLIGHT PLANNINGEach flight should be planned adequatelyto ensure safe operations and to providethe pilot with the data to be used duringflight. Essential weight, balance, andperformance information should becompiled as follows:

Check type of flight to be performed anddestination.

Select appropriate performance chartsto be used.

2-2-A. TAKEOFF AND LANDING

Refer to the Limitations section for takeoffand landing weight limits and to thePerformance section for takeoff andlanding distance information.

2-2-B. WEIGHT AND BALANCE

Determine proper weight and balance ofthe helicopter as follows:

Consult Section 5 for instructions.

Compute takeoff and anticipated landinggross weight, check helicopter center ofgravity (CG) locations, and determineweight of fuel, oil, payload, etc.

Check that loading limitations listed inSection 1 have not been exceeded.

Refer to Section 1, Limitations, forsubsystems restrictions.

2-3

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BHT-412-FM-4

2-3. PREFLIGHT CHECK

The pilot is responsible for determiningwhether the helicopter is in condition forsafe flight. Refer to figure 2-1 for preflightcheck sequence.

NOTE

The pilot walk-around and interiorchecks are outlined in thefollowing procedures. Thepreflight check is not intended tobe a detailed mechanical check,but simply a guide to help thepilot check the condition of thehelicopter. It may be made ascomprehensive as conditionswarrant, at the discretion of thepilot.

All areas checked shall include avisual check for evidence ofcorrosion, particularly whenhelicopter is flown near or oversalt water or in areas of highindustrial emissions.

2-3-A. BEFORE EXTERIORCHECK

Flight planning - Completed.

Gross weight and CG - Compute (referto Section 5).

Publications - Checked.

Portable fire extinguishers - Conditionand security.

Aft fuel sumps - Drain samples asfollows:

FUEL TRANS switches - OFF.

BOOST PUMP switches - OFF.

ENGINE 1 and ENGINE 2 FUELswitches - OFF.

BAT BUS 1 switch - ON.

FAA APPROVED

Aft fuel sump drain buttons (left andright) - Depress.

NOTE

If aft sumps fail to drain, sumpvalves may be operated manually.

Forward and middle fuel sumps - Drainsamples as follows:

Press-to-drain valves - Press.

Fuel filters - Drain before first flight ofday as follows:

BOOST PUMP switches - ON.

ENGINE 1 and ENGINE 2 FUELswitches - ON.

Fuel filter (left and right) - Drainsamples.

ENGINE 1 and ENGINE 2 FUELswitches - OFF.


BAT BUS 1 switch - OFF.

Main and tail rotor blade tie downs -Remove and stow.

Pitot tube cover(s) - Remove andstow.

No. 1 and 2 engine air intake covers -Remove and stow.

2-3-B. EXTERIOR CHECK.

WARNING

IF HELICOPTER HAS BEENEXPOSED TO SNOW OR ICINGCONDITIONS, SNOW AND ICESHALL BE REMOVED PRIOR TOFLIGHT.

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1. FUSELAGE - FRONT N11 governor spring - Check condition.

Cabin nose - Condition; all glass clean; Engine fire extinguisher - Check bottlewipers stowed. pressure gauge and temperature range.

Remote hydraulic filter bypass indicator Combining gearbox filter - Check- Verify normal. bypass indicator retracted.

Pitot tube(s) - Unobstructed. Oil cooler blower - Unobstructed.

Static ports (left and right) - Avionics compartment - Security ofUnobstructed. components; check OVER TRQ warning

flag (cat's eye) for indication ofCabin nose ventilators - Unobstructed.overtorque. AFCS computers - Secured;

Nose compartment door - Secure. compartment door secured.

Battery vent and drain tubes - Access doors and engine cowling -Unobstructed. Secured.

Searchlight and landing light - Stowed. Drain lines - Clean and unobstructed.

Antennas - Condition and security. Engine exhaust ejectors - Coversremoved; unobstructed.

2. FUSELAGE - CABINE LEFT SIDE.

Copilot door - Condition and operation;glass clean. Check security ofemergency release handles. Tailboom - Condition; access covers

Position lights - Condition. secured.

Passenger door - Condition and Tail rotor driveshaft covers - Secured.operation; glass clean. Condition of pop-out windows.

CAUTIONLanding gear - Condition; handlingwheels removed. DO NOT BEND ELEVATOR TRAILING

EDGE TAB.Passenger step (if Installed) - Conditionand security. Elevator - Condition and security.

Check for spring condition by moving3. FUSELAGE - AFT LEFT SIDE elevator toward the leading edge down

position.No. 1 engine compartment - Check.

Tail rotor (90x) gearbox - Verify actualNo. 1 engine oil level - Verify actual presence of oil in sight gauge. Visuallypresence of oil In sight gauge. Visually check oil level, check filler cap and chipcheck oil level. Filler cap secured. detector plug for security.

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Tail rotor blades - Visually check 6. FUSELAGE - CABIN RIGHT SIDEcondition and cleanliness.

Passenger door- Condition andTail rotor - Condition and free operation, glass clean. Condition ofmovement on flapping axis. pop-out windows.

Tail rotor yoke - Evidence of static Transmission oil - Verify actualstop contact damage (deformed static presence of oil in sight gauge.stop yield indicator). Visually check oil level.

Tail skid - Condition and security. Position lights - Condition.

Intermediate (42) gearbox - Verify Landing gear - Condition, handlingactual presence of oil in sight gauge. wheels removed.Visually check oil level. Check fillercap and chip detector plug for Passenger step (if installed)

security. Condition and security.

Condition and security. Pilot door - Condition and operation,glass clean. Check security ofTailboom - Condition. emergency release handles.

Baggage compartment - Cargo 7. CABIN TOPsecured, smoke detector condition, Hub and sleeve assembly - Checkdoor secured. condition.

5. FUSELAGE - AFT RIGHT SIDE. Swashplate, support assembly, and

compartment - Check collective lever - Check condition.

unobstructed. Main rotor pitch links - Security andcondition.

Tail rotor actuator - Check.Main rotor hub - Check general

Engine fire extinguisher - Check condition:bottle pressure gauge andtemperature range. Mast retaining nut - Secured.

Combining gearbox oil level - Verify Yoke assembly - Condition.actual presence of oil In sight gauge.Visually check oil level. Pitch horns - Security and

condition.Oil cooler blower - Unobstructed.

Elastomeric bearings, lead-lagNo. 2 engine compartment - Check. dampers - Check general

condition.No. 2 engine oil level - Verify actualpresence of oil in sight gauge. Blade retention bolts - SecurityVisually check oil level. Filler cap and proper latching.secured.

Droop restrainers - Security andAccess doors and engine cowling - condition.Verify droop stop clevis isSecured. in lower position of cam plate.

Fuel filler - Visually check quantity; Simple pendulum absorbers -secure cap. Security and condition.

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Rotor blades - Visually check conditionand cleanliness.

Main driveshaft and coupling -Condition, security and grease leakage.Check Temp-Plates (four places eachcoupling) for evidence of elevatedtemperature indicated by dot changingcolor to black.

CAUTION

IF ANY TEMP-PLATE IS MISSING ORHAS BLACK DOTS, MAINTENANCEPERSONNEL SHALL ASSIST INDETERMINING AIRWORTHINESS.

Transmission oil filler cap - Secured.

No. 1 and No. 2 hydraulic reservoirs -Visually check fluid levels; caps secured.

Antenna(s) - Condition and security.

Combining gearbox oil filler cap -Secured.

Anticollision light - Condition andsecurity.

No. 1 and No. 2 engine air intakes -Unobstructed; check particle separatordoors closed.

Engine and transmission cowling -Secured.

Fresh air inlet screen - Unobstructed.

Rotor brake reservoir cap - Security.

2-4. INTERIOR AND PRESTARTCHECK

Cabin interior - Cleanliness and securityof equipment.

Cargo and baggage (if applicable) -Check security.

Protective breathing equipment (ifinstalled) - Condition and properlyserviced.

NOTE

Opening or removing doors shiftshelicopter center of gravity andreduces VNE. Refer to Section 1 andSection 5.

Passenger doors - Secured.

Seat and pedals - Adjust.

Seat belt and shoulder harness - Fastenand adjust.

Shoulder harness inertia reel and lock -Check.

Directional control pedals - Checkfreedom of movement, position forengine start.

Flight controls - Position for start,friction as desired.

EEPROM READ switch - Locked indown position.

Transmission chip detector indicators -Check, reset if required.

Lower pedestal circuit breakers - IN.

Collective control head switches - OFF.

COMPASS CONTROL panel switches -MAG position (normal slaved).

AHRS control panel switches - MAGposition (locked). (S/N 36248 andsubsequent)

Radio equipment - OFF.

FUEL INTCON switch - NORM.

FUEL TRANS switches - OFF.


FUEL XFEED switch - NORM.

Rev. 19 2-7

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ENGINE 1 and ENGINE 2 FUEL switches- OFF.

PART SEP switches - NORM.

ENGINE 1 and ENGINE 2 GOV switches- AUTO.

HYDR SYS NO.1 and NO.2 switches -ON.

STEP switch (if installed) - As desired.

ROTOR RPM audio switch - Springloaded to AUDIO.

FORCE TRIM switch - ON, cover down.

Instruments - Static check.

STATIC SOURCE switch (if installed) -PRI.

APPROACH PLATE AND MAP LIGHTknob(s) - OFF.

AUX SYS PITOT and STATIC switches (ifinstalled) - NORM.

Altimeter(s) - Set.

Clock - Set and running.

FIRE EXT switch - OFF.

FIRE PULL handles - In (forward).

AFT DOME LIGHT rheostat and switch -OFF.

PITOT STATIC HEATERS switch - OFF.

WIPER switches - OFF.

CARGO RELEASE switch (if installed) -OFF.

HEATER switch - OFF.

AFT OUTLET switch - OFF.

VENT BLOWER switch - OFF.

EMERG LT switch (if installed) -DISARM.

STBY ATT switch (if installed) - TEST;check standby attitude indicator lightilluminates and OFF flag retractsmomentarily, then switch OFF.

WSHLD HEAT switches (if installed) -OFF.

Overhead circuit breakers - In.

All LT rheostats - OFF.

UTILITY LIGHT switch - OFF.

POSITION light - OFF.

ANTI COLL light - ON.

EMERG LOAD switch - NORMAL.

NON-ESNTL BUS switch - Springloaded to NORMAL.

INV 1 and 2 switches - OFF.

GEN 1 and 2 switches - OFF.

IF EXTERNAL POWER IS USED -CONNECT (1000 AMPS MAXIMUM).CHECK 27 1 VDC; ADJUST POWERSOURCE IF REQUIRED.

BATTERY BUS 1 and BUS 2 switches -ON; check BATTERY caution lightilluminates.

NOTE

Test operate all lights when nightflights are planned or anticipated.Accomplish light tests withexternal power connected orduring engine runup.

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INV 1 and 2 switches - ON.NOTEIf Anticollision light is desired,NON-ESNTL BUS - MANUAL.

ROTOR BRAKE lights - Test. Pullbrake ON and check that both lightsilluminate; return to OFF and checklights extinguish.

NOTE

Rotor brake shall be off at alltimes when the engines arerunning.

FIRE 1 and 2 warning lights test button- Press to test.

BAGGAGE FIRE warning light testbutton - Press to test (verify lightflashes).

OVER TORQ caution light - Press.Check light illuminates and MASTTORQUE indicator reads 105 1%.

CAUTION

IF MAST TORQUE INDICATORINDICATES AN ERROR GREATERTHAN 1% FROM THE 105%POSITION, THE MAST TORQUESYSTEM IS UNRELIABLE.MAINTENANCE ACTION ISREQUIRED.

CYC CTR caution lights - Press to test.

Caution panel TEST switch - PNL (Allsegments extinguish except CAUTIONPANEL).

Caution panel TEST switch - LT (Allsegments illuminate).

Caution panel RESET button - Press(MASTER CAUTION light extinguishes).

FUEL SYS test switch - FWD TANK,then MID TANK; note digital and needleindications.

FUEL SYS DIGITS TEST button - Press(digital display reads 888).

2-5. ENGINE START

NOTE

If the helicopter has been coldsoaked in ambient temperaturesof -18C (0F) or less, boththrottles will be difficult to moveand follow through coupling maybe increased.

Throttles - Rotate engine 1 throttle fullopen, then back against idle stop.Actuate ENG 1 IDLE STOP release, rollengine 1 throttle to full closed, thenapply friction as desired. Repeatprocedure using engine 2 throttle andENG 2 IDLE STOP release.

NOTE

When either IDLE STOP release isactivated, the appropriate idlestop plunger will not release ifpressure is applied toward theclosed position of the throttle.

Moderate frictions should be applied toovercome follow-through couplingbetween throttles.

RPM INCR/DECR switch - DECR for 8seconds.

2-5-A. ENGINE 1 START

NOTE

Either engine may be started first.However, the following procedureis provided for starting engine 1first.

At ambient temperatures 5C(41F) and below, refer toparagraph 2-5-F.

Engine 1 FUEL TRANS switch - ON,check NO. 1 FUEL TRANS caution lightextinguished.

Rev. 17 2-9

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Engine 1 BOOST PUMP switch - ON,check NO. 1 FUEL BOOST lightextinguished.

Engine 1 FUEL switch - ON. (FUELVALVE caution light will illuminatemomentarily.)

Engine 1 FUEL PRESS indicator -Check.

Rotor - Clear.

CAUTION

PROLONGED EXPOSURE TOAMBIENT TEMPERATURES OF0C (32F) OR LESS MAY FREEZEMOISTURE IN THE ENGINE FUELCONTROL SYSTEM. MONITORENG RPM (N) DURING COLDWEATHER STARTING FOROVERSPEED. IF AN OVERSPEEDAPPEARS IMMINENT, ABORTSTART AND CLOSE THROTTLETO OFF POSITION.

START switch - ENG 1 position.Observe starter limitations.

Engine 1 ENGINE OIL pressure -Indicating.

Engine 1 throttle - Open to idle at 12%GAS PROD RPM (N,) minimum.

Engine 1 ITT - Monitor to avoid a hotstart. Maximum ITT during start is1090C, not to exceed two secondsabove 960C. If ITT continues to rise,abort start by activating idle stoprelease and rolling throttle to fullyclosed. Starter should remain engageduntil ITT decreases. Do not attemptrestart until corrective maintenance hasbeen accomplished.

NOTE

If engine fails to start, refer toparagraph 2-5-D procedures.

Collective pitch - Ensure in full downposition.

CAUTION

IF STICK CENTERING INDICATORSYSTEM IS INOPERATIVE,GROUND OPERATION SHALL BECONDUCTED AT 97% ROTORRPM OR ABOVE.

NOTE

On side slopes greater than fivedegrees, disregard CYC CTRcaution lights and position cyclicas desired.

Cyclic - Position as necessary toextinguish CYC CTR caution lights.

NOTE

CYC CTR caution lights areinhibited between 95 and 105%ROTOR RPM.

START switch - Centered (off) at 55%GAS PROD RPM (N,).

GAS PROD - Check 61 + 1% whenthrottle is on idle stop.

NOTE

Do not increase ROTOR above85% RPM until XMSN oiltemperature is above 15C.

ENGINE, XMSN, and GEAR BOX OILPRESSURES- Check.

Engine 1 PART SEP OFF caution light -Check extinguished.

CAUTION

DURING RPM INCREASE, ANYABNORMAL INCREASE IN ONE-PER-REV VIBRATION MAYINDICATE ONE OR MORE MAINDROOP RESTRAINERS FAILEDTO DISENGAGE FROM STATICPOSITION. VERIFY PROPEROPERATION PRIOR TO FLIGHT.

I

2-10 Rev. 17

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Engine 1 throttle - increase to 77 - 85%ENG RPM (Ni). Friction as desired.

NOTE

Minimize blade flapping bymaintaining highest rotor RPM(NR) within allowable range.

Rotor RPM (NR) - Minimum 77 - 85%, asdesired.

Engine 2 FUEL PRESS - Check.

START switch - ENG 2 position.Observe starter limitations.

Engine 2 ENGINE OIL pressure -Indicating.

Engine 2 throttle - Open to idle at 12%GAS PROD RPM (N,).

Engine 2 ITT - Monitor. Observe ITTlimitations.

NOTE

If external power is used, proceedto engine 2 start. If battery wasused, proceed as follows:

N, RPM - Check 71% minimum.

GEN 1 switch - ON.

NOTE

Before attempting generatorassisted start on second engine,it is recommended that the batterybe charged until the ammeter loaddrops below 150 amps.

AMPS 1 indicator - Check at or below150 amps.

2-5-B. ENGINE 2 START

NOTE

At ambient temperatures of 5C(41F) and below, refer toparagraph 2-5-F.

Engine 2 FUEL TRANS switch - ON.Check NO. 2 FUEL TRANS caution lightextinguished.

Engine 2 BOOST PUMP switch - ON.Check No. 2 FUEL BOOST light out(FUEL XFEED caution light willilluminate momentarily.)

Engine 2 FUEL switch - ON (FUELVALVE caution light will illuminatemomentarily).

START switch - Centered (off) at 55%GAS PROD RPM (N,).

GAS PROD - Check 61+1% RPM (N,)when engine 2 throttle is on Idle stop.

CAUTION

ENSURE SECOND ENGINEENGAGES AS THROTTLE ISINCREASED. A NONENGAGEDENGINE INDICATES 10 TO 15%HIGHER N,, RPM THAN THEENGAGED ENGINE AND NEARZERO TORQUE. IF ANONENGAGEMENT OCCURS,CLOSE THROTTLE OF THENONENGAGED ENGINE. WHENTHE NONENGAGED ENGINE HASSTOPPED, SHUT DOWN THEENGAGED ENGINE.IF A SUDDEN (HARD)ENGAGEMENT OCCURS, SHUTDOWN BOTH ENGINES.MAINTENANCE IS REQUIRED.

Engine 2 throttle - Increase slowly tomatch Engine 1 N,, rpm. Monitortachometer and torquemeter to verifyengagement of second engine.

Engine 2 oil pressure - Check.

ENG 2 PART SEP OFF caution light -Check extinguished.

2-5-C. POST START

Rev. 17 2-11

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Radios - ON as required.

N R - 77 - 85% or above.

NOTE

If external power was used -Disconnect. GEN 1 switch - ON.

ELT (if installed) - Check forinadvertent transmission.

2-5-D. ENGINE FAILS TO START

GEN 2 switch - ON. (BAT BUS 1 willswitch off automatically.)

CAUTION

ONLY BATTERY BUS 2 SWITCHSHOULD REMAIN ON WITH BOTHGENERATORS OPERATING.

NOTE

During rpm increase, anyabnormal increase in 1 per revvibration may indicate one ormore main rotor droop restraintsfailed to disengage from staticposition. Verify proper operationprior to operating.

When the engine fails to start within 15seconds after the throttle has beenopened to idle, the following action isrecommended:

IDLE STOP release - Actuate.

Throttle - Fully close.

Starter - Disengage.

BOOST PUMP switch - OFF.

FUEL switch - OFF.

After GAS PROD RPM (N1) hasdecreased to zero, allow 30 secondsfor fuel to drain from engine.

Caution lights - Check all extinguished(except AFCS).

ENGINE, XMSN, and GEAR BOX OILtemperatures and pressures - Withinlimits.

AMPS 1 and 2 - Within limits.

NOTE

AMPS 2 will indicate a higher loadthan AMPS 1 until battery is fullycharged.

Conduct a DRY MOTORING RUN beforeattempting another start.

2-5-E. DRY MOTORING RUN

The following procedure is used to clearan engine whenever it is deemednecessary to remove internally trappedfuel and vapor.

Throttle - Fully closed.

BOOST PUMP switch - ON.

2-12 Rev. 17

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FUEL switch - ON.

IGN circuit breaker- Pull out.

Starter - Engage for 15 seconds, then At ambient temperature 5C (41 F) and below,disengage. incorporate warmup procedures as follows:

BOOST PUMP switch - OFF.

FUEL switch - OFF.FUEL switch - OFF. ENG 1/2 throttle - Open slowly to

IGN circuit breaker - Push in. maintain 77 - 85% ENG RPM as desired(minimum 3 minutes).

Allow the required cooling period forthe starter before proceeding. Follow After warm-up:normal start sequence as described onpreceding pages. Throttle - Reduce to idle.

GOV switch - Return to AUTO.2-5-F. COLD WEATHER START

This procedure is applicable to either engine. CAUTION

DO NOT ALLOW GAS PRODUCER TODECREASE BELOW 50% RPM (N1).

NOTE

During extremely cold ambienttemperatures, idle rpm will be high andthe ENGINE, XMSN, and GEAR BOX OILpressure may exceed limits for up totwo minutes after starting. Warm upshall be conducted at 77 - 85% NR atflat pitch.

Continue start sequence per paragraph 2-5-Aor 2-5-B.

Rev. 20 2-12A / 2-12B

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2-6. SYSTEMS CHECK2-6-B. FORCE TRIM CHECK

2-6-A. STICK CENTERING Flight controls - Friction off, collective2-6-A. STICK CENTERING lock removed.lock removed.INDICATOR CHECK

Cyclic and pedals - Move slightly eachCAUTION direction to check force gradients.

CAUTION Yaw trim release switch (if installed) -Press forward. Check yaw trim onlyreleases, reengages with switchreleased.

DURING EXTREME COLDAMBIENT TEMPERATURES LIMIT Cyclic FORCE TRIM release button -CYCLIC MOVEMENTS UNTIL Depress. Check trim releases withXMSN OIL TEMPERATURE button depressed, reengages withREACHES 15C. button released.

FORCE TRIM switch - OFF. Check trimadisengages and FT OFF caution light

CAUTION illuminates.

FORCE TRIM switch - ON, cover down.DO NOT DISPLACE CYCLIC MORETHAN 1.5 INCHES FROM CENTER 2-6-C. PRELIMINARY HYDRAULICTO CHECK THE SYSTEM. IF CYC CHECKCTR CAUTION LIGHTS DO NOTILLUMINATE WITHIN THE 1.5 Throttles - Set to idle.INCH DISPLACEMENT, THESYSTEM IS INOPERATIVE. NOTE

Uncommanded control movementDO NOT DISPLACE CYCLIC or motoring with either hydraulicBEYOND POINT AT WHICH CYC system off may indicate hydraulicCTR CAUTION LIGHT system malfunction.ILLUMINATES. NO. 1 HYD SYS switch OFF, then ON.

NOTE NO. 2 HYD SYS switch - OFF, then ON.

CYC CTR caution lights areinhibited between 95 and 105%ROTOR RPM.

Cyclic - Displace approximately 1.25Inch (31.7 mm) forward, aft, left and. right. Check CYC CTR caution lightilluminates each time when displacedand extinguishes when centered.

Rev. 17 2-13

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BHT-412-FM-4 FAAAPPROVED

2-6-D. ENGINE FUEL CONTROL Engine 2 throttle - Full open. Check No. 1CHECK engine Increases 2% ENG RPM (Ni,) and

both engines stabilize at 97 1% ENG RPMThrottles (both) - Idle. (Nil).

(NOTECAUTION Helicopters rigged for Category A

operations will obtain 103% ENGDO NOT ALLOW GAS PROD TO RPM (Nn). Refer to Flight ManualDECREASE BELOW 50% RPM Supplement BHT412-FMS-62.3 &(N.). 62.4 for Airspeed Limitations.

NOTE RPM INCR/DECR switch - Full INCR. CheckIn the vicinity of 8000 feet ENG does not exceed 101.5% RPM (Nn). Setpressure altitude, GAS PROD at 100% ENG RPM (Nn).RPM (N.) may not changesignificantly when manual fuel 2-6-F. FUEL CROSSFEED ANDcontrol is selected. INTERCONNECT VALVE CHECK

GOV switch (ENGINE 1 or 2) - MANUAL FUEL XFEEDNTCON test switch TESTobserve a change in GAS PROD RPM (N|) BUS 1 and hold.and GOV MANUAL caution light illuminates.

Open respective throttle carefully to ensure NOTEGAS PROD RPM (N|) responds upward, then After turning either boost pumpreturn to idle position. off, FUEL BOOST caution light

should illuminate on failed sideReturn GOV switch to AUTO. Check for a only.return to original GAS PROD RPM (N|) andGOV MANUAL caution light extinguishes. ENGINE 1 BOOST PUMP switch - OFF.

Check Engine I FUEL PRESSURECheck second governor in like manner. decreases, then returns to normal. (This

indicates crossfeed valve has been openedThrottles (both) - Increase slowly above by Bus No. 1 power and check valve is85% ROTOR RPM. functioning properly). Return switch to ON.

2-6-E. GOVERNOR CHECK FUEL INTCON switch - OPEN. Check FUELINTCON caution light Illuminates thenextinguishes. (This Indicates interconnect

CAUTION valve has been opened by BUS NO. 1 powerand that the valve is functioning properly).

IF HELICOPTER IS SITTING ONICE OR OTHER SLIPPERY OR FUEL INTCON switch - OVRD CLOSE.LOOSE SURFACE, ADVANCE Check FUEL INTCON caution lightTHROTTLES SLOWLY TO illuminates then extinguishes.PREVENT ROTATION OFHELICOPTER. FUEL XFEED/INTCON test switch - TEST

Engine 1 throttle - Fully open. BUS 2 and hold.

ENGINE 2 BOOST PUMP switch - OFF.ENG - Stabilized at 95 1% RPM (N||). ENGINE 2 BOOST PRESS decreaseCheck engine 2 FUEL PRESS decreases,then returns to normal. Return switch to ON.

2-14 Rev. 22 11 JUN 2001

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FAA APPROVEDFAA APPROVED BHT-412-FM-4

BHT-412-FM-4

FUEL INTCON switch - OPEN. CheckFUEL INTCON caution light illuminatesthen extinguishes. (This indicates thatthe interconnect valve has been openedby BUS NO. 2 power and that the valveis functioning properly).

FUEL INTCON switch - NORM. CheckFUEL INTCON caution light illuminatesthen extinguishes.

FUEL XFEED/INTCON test switch -NORM.

FUEL XFEED switch - OVRD CLOSE.

ENGINE 1 BOOST PUMP switch - OFF.Check fuel pressure drops to zero onaffected system. Return switch to ON.Repeat procedure for ENGINE 2 BOOSTPUMP switch.

FUEL XFEED switch - NORM.

2-6-G. ELECTRICAL SYSTEMSCHECK

DC VOLTS - Check 27 1 volts.

AC VOLTS - Check 104 to 122 volts

AMPS 1 and 2 - Check within limits.

GEN 1 and 2 switches - OFF.

EMERG LOAD switch - EMERG LOAD.Check that the following items remainoperational:

AP 2.

EMERG LOAD switch - NORMAL

GEN 1 and 2 switches - ON

INV 1 switch - OFF; check INVERTER 1caution light illuminates. Check No. 1and No. 2 AC VOLTS for indication thatinverter 2 has assumed all ac loads.Return INV 1 switch to ON.

INV 2 switch - OFF; check INVERTER 2caution light illuminates. Check No. 1and No. 2 AC VOLTS for indication thatinverter 1 has assumed all ac loads.Return INV 2 switch to ON.

STBY ATT switch (if installed) - ON.

EMERG LT switch (if installed) - TEST;check all emergency lights illuminate.Switch to ARM; check lights dim to faintglow.

2-6-H. HYDRAULIC SYSTEMSCHECK

NOTE

The Hydraulic Systems Check isto determine proper operation ofthe hydraulic actuators for eachflight control system. If abnormalforces, unequal forces, controlbinding or motoring areencountered, it may be anindication of a malfunctioningflight control actuator.

FORCE TRIM switch - OFF.

VHF #1.

Pilot map light

Pilots ICS

STBY ATT indicator

Collective - Full down, frictionremoved.

Rotor - Set to 100% RPM.

Cyclic - Centered, friction removed.

Essential engine instruments (Refer toBHT-412-MD-4 for a complete list ofEMER BUS components).

HYDR SYS NO. 1 switch - OFF. CheckNO. 1 HYDRAULIC caution light andMASTER CAUTION light illuminate andsystem 1 pressure drops to zero.

Rev. 9 2-15

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Cyclic - Check normal operation bymoving cyclic forward, aft, left, and rightapproximately one inch. Center cyclic.

Collective - Check for normal operationby increasing collective control 1 to 2inches. Repeat 2 to 3 times as required.Return to full down position.

Pedals - Displace slightly left and right.Note an increase in force required tomove pedal in each direction.

NOTE

An electrical interlock prevents bothhydraulic systems from being switchedoff at the same time. If one system is offand the second system is switched off,the second system will remain on.

HYDR SYS NO. 2 switch - OFF. Checkhydraulic system 2 remains operationaland system 1 remains off.

HYDR SYS NO. 1 switch - ON. CheckNO. 1 HYDRAULIC caution lightextinguishes and system 1 regainsnormal pressure. Check NO. 2HYDRAULIC caution light illuminates andsystem 2 pressure drops to zero.

Cyclic - Check normal operation bymoving cyclic forward, aft, left, and rightapproximately one inch. Center cyclic.

Collective - Check for normal operationby increasing collective control 1 to 2inches. Repeat 2 to 3 times as required.Return to full down position.

Pedals - Displace slightly left and right.Note the pedals are now boosted.

HYDR SYS NO. 2 switch - ON. CheckNO. 2 HYDRAULIC caution lightextinguishes, system 2 pressure returnsto normal, and hydraulic system 1remains operational.

Cyclic and collective friction - Set asdesired.

FORCE TRIM switch - ON. Check FTOFF caution light extinguishes.

WARNING

BOTH HYDRAULIC SYSTEMS SHALLBE OPERATIONAL PRIOR TOTAKEOFF.

NOTE

System 1 will normally operate 10 to 20C cooler than system 2.

2-6-J. AFCS CHECK

NOTE

Verification of AFCS actuator centeringis necessary. Failure of the actuators tocenter could result in reduced controlmargins (pitch and roll) and abnormalcontrol positions (pitch, roll, and yaw).

NOTE

For S/N 36087 - 36247, if fast slaving isdesired, center ADI roll trim knob, thenpush and hold VG FAST ERECT buttonuntil attitude indicator displays zerodegrees bank angle. Use of VG FASTERECT button will disengage therespective autopilot.

I

Pilot and copilot attitude indicators -Erect and set as necessary.

WARNING

IF AFCS IS LEFT ENGAGED IN ATTMODE DURING GROUND OPERATION,IT CAN DRIVE THE CYCLIC STICK TO ACONTROL STOP.

2-16 Rev. 19

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Verify AP 1 and AP 2 are disengaged. completion of AFCS CHECK.

Cyclic force trim switch - Check ON. Press TEST switch to exit AFCS test.

For helicopters not equipped with Flight 2-6-K. AHRS CHECK (S/N 36248 ANDDirector Kit: Press and hold the CPL switch SUBSEQUENT)on autopilot control panel. While holding CPLswitch, press the TEST switch. Release both Confirm AFCS TEST flashing, ADI Pitch andswitches -verify TEST ON. Roll adjustment indicies aligned, press and

hold AHRS control Panel No. 1 and No. 2NOTE TEST switches.

AUTO TRIM light will remainilluminated during AFCS test. NOTE

Test may be performed in MAG or DGmode.If TEST accomplished in DGmode, heading must be manuallyaligned.

Verify following responses for each system:AFCS TEST switch - ON for level 1 test.

Verify AL-300 Air Data Display (ADD) HSIreads LE 1.

Heading Rotates to 015Verify AP 1 light flashes, then press.Heading OFF Flag In view

NOTEADI

Pilot shall closely monitor controlsduring test, taking care not to restrict Pitch 5 nose upcontrol movements. To preventnuisance failures, hands must remain Roll 45 rightoff controls.

Cyclic-- Verify movement aft rightapproximately one inch, then return to ATT Flag In viewneutral.

Verify AP 2 light flashes, then press. RT Flag In view

Cyclic - Verify movement aft right AHRSapproximately one inch, then return to CONTROLneutral. PANEL

Upon completion of test, verify AP 1 andAP 2 lights extinguish and AL-300 reads * / + Indicator Needle Deflection - *END 1.

If error codes are present, press SBY (orcyclic NAV STBY switch) once to vieweach code until END 1 is displayed (referto table 3-3 for a list of error codes).(AHRS equipped helicopters) - Proceedto paragraph 2-6-K AHRS CHECK prior to Press AFCS TEST switch to exit test mode.

Rev. 20 2-17

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2-6-L. CABIN HEATER CHECK Within operating ranges.

GAS PROD - Check 75% RPM (N1) Caution and warning lights -minimum (both engines). Extinguished.

Thermostat knob - Full COLD. Flight instruments - Check operationand set. When flying IFR check asfollows:

CAUTION IVSI - Needle near zero.

HEATER SWITCH SHALL BE Altimeter - Set and check.TURNEDOFF WHEN HEATED AIRFLOWDOES NOT SHUT OFF AFTER HSI - Check.THERMOSTAT IS TURNED TO FULLCOLD, HEATER AIR LINE LIGHT ADI - Check.ILLUMINATES, OR CABIN HTR CIRCUITBREAKER TRIPS. Radio Altimeter - Zero altitude, OFF flag

retracted, DH set as desired.

CAUTIONWARNING

DO NOT OPERATE HEATER ABOVE 21C OAT. IF AFCS IS LEFT ENGAGED IN ATT

HEATER switch - ON. MODE DURING GROUND OPERATION,IT CAN DRIVE THE CYCLIC STICK TO A

VENT BLOWER switch - ON. CONTROL STOP.

Thermostat setting - Increase and AFCS - AP 1 and AP 2 engaged andobserve heated airflow. select ATT or SAS mode as desired (ATT

mode shall be used during IFR flight;DEFOG lever - ON. Check airflow is SAS mode recommended for grounddiverted from pedestal outlets to operations, hover, andtakeoff).windshield nozzles. Return lever to OFF.

TRIM/FD 1 or 2 - As desired.AFT OUTLET switch - ON. Check airflow TRIM/FD 1 or 2-As desired.distributed equally between pedestal FORCE TRIM Switch - ON in ATT mode,outlets and aft outlets. Return switch to as desired in SAS mode.OFF.

Auxiliary navigation Panel - As desired.

NOTE

Heater operation affects performance.Refer to Hover Ceiling and Rate ofClimb charts for HEATER ON in Section MODERATE FRICTION SHALL BE4. APPLIED TO OVERCOME FOLLOW-

THROUGH COUPLING BETWEENHEATER switch - As desired. THROTTLES.

VENT BLOWER switch - As desired. Throttles - Full open. Adjust frictions.

2-7. BEFORE TAKEOFF ENG - 100% RPM (N11) for both engines.

Engine, gearbox, transmission, POSITION lights - As required.hydraulic, and electrical instruments -2-18 Rev. 19

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ANTI COLL light Check ON.

PITOT-STATIC HEATERS switch ON. Check ammeter for load indication. Leave ON in visible moisture when temperature is below 4.4C (40F) OFF if not required.

Radio(s) Check functioning.

EMERGENCY COMM panel (If installed) Check for single pilot operations.

Cyclic control Centered or slightly into the wind.

bht-412-fm-4 bell 412ep flight manual

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