TECHNICAL MANUAL MAINTENANCE MANUAL FOR ARMY CH-47D HELICOPTER (1992)

TM 55-1520-240-10

NOTE

26. Ignition lock switch - OFF, key removed as

required.

Monitor temperatures during shutdown. If

27. EMERGENCY POWER panel - Check flag

temperatures rise above 350°C, motor en-

indicators for tripped position.

gine immediately until temperature de-

creases below 260°C. Both engines cannot

8-43. Before Leaving Helicopter.

be motored at the same time.

1. Walk-around inspection - Perform. Checking

FL* 17.1

714A

DECU SHUTDOWN BIT - Check

for damage, fluid leaks and levels.

displays read 88.

2. Check the following:

NOTE

a. Fluid levels.

If DECU display is other than 88, advance

b. Bypass indicators and filter buttons.

respective ECL to GND without starting en-

gines. If 88 is displayed, then a nuisance fault

c. Jam indicators.

has been verified. If other than 88 is dis-

d. Cabin and mission equipment secured.

played, refer to maintenance.

e. Tiedowns, grounding cables, and covers.

18. Avionics - OFF.

3. Complete all forms and records.

18.1 HUD - OFF.

4. Helicopter - Secure as required.

19. Radar altimeters - OFF.

20. MAINTENANCE PANEL - Check record any

8-44. Instrument Flight - General.

bite indications on DA Form 2408-13.

21. PWR XFER 1 and 2 switches - OFF after

This aircraft is qualified for operation in instrument

rotors have stopped.

meteorological conditions.

21.1

714A

FADEC B/U PWR - OFF.

8-45. Instrument Flight Procedures. Refer to FM

22. APU GEN switch - OFF.

1-240, FM 1-230, FLIP, AR 95-1, FAR Part 91, and

procedures described in this manual.

23. APU switch - OFF. The APU may be shut

down after the rotors have stopped and there

8-46. Night Flying.

is no further need to motor the engines.

24. Light switches - OFF as required.

Refer to FM 1-204, Night Flight Techniques and Proce-

25. BATT switch - OFF.

dures.

Change 17

8-14.1/(8-14.2 blank)

TM 55-1520-240-10

SECTION III FLIGHT CHARACTERISTICS

8-47. GENERAL.

partially dislodge the housing and engage

or activate the forward and aft hook emer-

The flight characteristics of the helicopter throughtout the

gency release mechanism. This may

flight envelope and at all gross weights are good. The

cause an inadvertent release of loaded

flight characteristics remain essentially the same

forward and aft hook assemblies in flight.

throughout the CG and GW range. There is no marked

degradation of flying qualities as altitude increases.

CAUTION

8-48. AFCS Off Flight Characteristics.

External loads must not be rigged entirely

The AFCS is required to provide the helicopter with ade-

with steel cable (wire rope) slings. To

quate stability. Therefore, the stability of the helicopter

dampen vibration tendencies, a nylon ver-

will be reduced when operating with AFCS off. With prac-

tical riser at least 6 feet long must be

tice, the pilot will know in advance what to expect and

placed between the steel cable sling and

should have little trouble controlling the helicopter as

the nylon loop or metal shackle which at-

long as established limitations (refer to Chapter 5) and

taches to the cargo hook. Nylon and chain

certain techniques are adhered to. In general, the AFCS

off flight characteristics are enhanced by spoilers on the

leg slings and pure nylon slings must

forward pylon, strakes on the fuel pods and ramp, and a

have at least 6 feet of nylon in each leg.

blunted aft pylon. The AFCS may be turned off at any

airspeed and turned back on at or near the turn-off air-

CAUTION

speed. If airspeed at turn-on is different from that at turn-

off, a low rate pitch transient accompanied by momentary

When combination internal and external

illumination of the AFCS OFF caution capsules may oc-

loads are carried during the same flight

cur. These symptoms indicate that a DASH error signal

and the external load exceeds

12,000

existed a turn-on and that the DASH actuator is running

pounds, position the internal load forward

at a reduced rate to cancel the error signal. When the

cautions are extinguished, the error signal is cancelled,

of the utility hatch. This procedure will

and normal DASH operation has resumed. During this

preclude encountering an excessively aft

period, when the error signal is being cancelled, the re-

CG.

maining AFCS features function normally. AFCS off flight

will not be difficult when the following techniques are

8-50. Low Density Loads When carrying low density

used:

loads, airspeed is limited by the amount of clearance

which can be maintained between the load and the un-

a. Maintain airspeed below established limits.

derside of the helicopter since the load will tend to trail aft

b. Enter all maneuvers smoothly, keep control move-

as speed is increased.

ments coordinated and avoid overcontrol.

8-51. High Density Loads. High density loads can

c. Consistently scan the turn-and-slip indicator to

usually be flown at cruise airspeed and in some cases up

maintain trim flight.

to Vne, depending on the configuration of the load, air

d. React positively but smoothly to divergent move-

turbulence, or accompanying vibration.

ments.

8-52. Aerodynamic Loads. Aerodynamic loads,

8-49. CENTER HOOK LOADS.

such as tow targets, drones, light aircraft, aircraft parts,

wings, and tail sections have certain inherent dangers

In general, the helicopter possesses excellent flight char-

because of their aerodynamic lift capabilities. Therefore,

acteristics when performing an external load mission.

the lift capabilities of external loads must be eliminated

The combination of power available, the load carried

before they are lifted. Airspeed and bank angles will be

beneath the CG, and the design of the cargo hook sys-

governed by the reaction of the load to the airspeed.

tem make loads of minimum or maximum weight relative-

Drogue chutes shall also be used to streamline the load.

ly easy to carry and handle safely. The type loads carried

However, the chute must be attached to the load with a

can usually be broken down into three major groups: low

swivel fitting.

density, high density, and aerodynamic. Each type load

8-53. Multi-Hook Loads. Handling characteristics

mentioned displays characteristics all its own and there-

are improved when loads are slung using two-point (for-

fore must be discussed separately.

ward and aft hook) sling suspension. Load motion is

substantially reduced. Potentially unstable loads are di-

CAUTION

rectionally restrained by two-point suspension; airspeed

capability is increased above the airspeed for single-

Do not lift or rotate the center cargo hook

point suspension. When low-density high-drag cargo is

into the cabin area or allow the mid hook

carried, the risk of single-hook failure in a two-point sus-

to lay on the cargo floor or access door

pension is reduced by the addition of a safety sling from

panel during inspection or use. The exces-

the center hook to the forward load attachment point. The

sive tension placed on the triple emergen-

multi-hook configuration also enables the carrying of

cy release cable housing assembly may

three independent loads within the CG limit.

Change 18

8-15

TM 55-1520-240-10

SECTION IV ADVERSE ENVIRONMENTAL CONDITIONS

8-54. COLD WEATHER OPERATION.

8-57. Heater Operation.

Refer to FM 1-202, Environmental Flight.

8-58. Normal Operation - Heating and Ventilat-

ing System.

8-55. General. Operating the helicopter in an envi-

ronment of extreme low temperature and the associated

weather phenomena requires that certain techniques

and operating procedures be implemented in addition

Cycling of the heater blower may disable

to the normal operating procedures in section II. The

power steering control.

following operating techniques and procedures have

been developed from actual arctic flight testing and

Starting.

other pertinent information.

(1)

Inlet and outlet covers - Remove.

8-56. Preparation for Flight. The following addi-

(2)

BATT switch - ON

tional exterior checks are to be performed during cold

weather operation.

(3)

APU - Start (para. 8-23).

a. Check that ail ice, snow, and frost have been

(4)

APU GEN switch

- ON. RECT OFF cau-

tion capsule extinguishes.

removed from the exterior surfaces, particularly the

rotor blades.

(5) R (right) MAIN FUEL PUMP switches -

ON.

CAUTION

Ice removal should never be accomplished by

chipping or scraping. Deicing fluid should be

Pull out the cockpit air knobs slowly to

used.

preclude dirt and debris from being blasted

into the air and the pilot’s eyes.

b. Landing gear shock struts, wheel brakes and flight

(6) Push in the air control knobs.

control system actuators should be checked to make

certain that exposed piston areas are free of dirt, ice,

(7) Heater function switch -

As desired (BLWR

etc.

ONLY or HTR ON).

(8) HTR START switch - Press.

c. While checking the engines, the compressor should

be manually checked for freedom of rotation. Heat must

NOTE

be applied if the compressor is frozen.

If the left side of the helicopter is exposed to

d. When operating the ramp, it maybe necessary to

the sun, the cabin thermostat may be heated

cycle it once or twice to achieve proper closure.

to 34°C which is sufficient to prevent starting

the heater.

e. Ensure that the manually operated vent valves on

the rotary-wing shock absorbers are open at tempera-

tures below

-18°C. At temperatures between

-18°C

(9) CABIN TEMP SEL switch - As desired.

and

-1°C, the vent valves may be open or closed. At

b. Heat Distribution.

temperatures above

-1°C, the vent valves must be

closed.

(1) For maximum cockpit heat proceed as fol-

lows:

f. If seasonal temperatures are

+4°C and below, the

(a) Pilot and copilot cockpit air control

aft rotor droop stop shrouds should be installed.

knobs - Pull.

g. At temperatures below

-18°C, preheating aircraft

(b) DEFOG OR DEFROST handle - Pull.

is recommended for a minimum of

1-1/2 hours. Empha-

sis should be placed on engine fuel control units.

(d) CABIN TEMP SEL switch - Full clock-

h. Refer to Chapter 5 for icing limitations.

wise.

(2) For maximum cabin heat proceed as follows:

(a) Pilot and copilot air control

knobs - Push.

8-16

TM 55-1520-240-10

(b)

DEFOG OR DEFROST handle - Push.

8-64. Taxiing. Difficulty will be encountered when

taxiing on ice and snow covered surfaces where braking

(c)

CABIN AIR handle - Pull.

action is poor. Taxiing on the aft gear (front wheels off

(d)

Cabin adjustable outlets - Full open.

the ground) is recommended; however, caution should

be taken because of the poor visibility resulting from

(e) CABIN TEMP SEL switch - Full clock-

blowing snow.

wise.

c. Stopping.

8-65. Takeoff. No unusual problems are associated

with either the hovering, rolling, or vertical-type take-

(1)

Heater function switch - OFF.

offs other than the effects of blowing snow and slippery

(2)

Wait two minutes before turning generator(s)

surfaces. Depending on the weight of snow and ice

off.

accumulated on or in the fuselage, takeoff and overall

performance can be seriously affected.

(3) After heating and ventilating system has been

stopped with the APU GEN ON, the blower

8-66. During Flight. Initial hovering with cold hy-

will continue to operate until the tempera-

draulic fluid may produce insensitive control inputs.

ture within the heater combustion chamber is

Hovering above 10 feet (aft wheel clearance) is recom-

below 49°C.

mended under these conditions until operation is nor-

mal. With AFCS on, light pitch and roll oscillations can

8-59. Alternate Operation - Heating and Venti-

be expected during the first 10 or 20 minutes of flight.

lating System.

The following paragraphs describe heating and ventilat-

8-67. Descent. No unusual problems are encountered

ing system failure modes.

during a descent. Use windshield heat if necessary.

8-60. Vibrator Contact Failure. The heater may be

8-68. Landing in Snow. Landing in loose snow from

equipped with either a solid-state vibrator or an elec-

a hover presents the unusual problem of low visibility

tromechanical vibrator. The electromechanical vibra-

caused by blowing snow. This helicopter does not

tors may experience vibrator contact failure, which will

produce this effect to any greater extent than other

result in failure of the heater to operate. Heaters

helicopters; however, caution should be exercised dur-

equipped with electromechanical vibrators are identi-

ing this type landing.

fied by a rotary selector switch on the heater junction

box. The electromechanical vibrator is equipped with

8-69. After Landing. Maneuvering the helicopter into

two separate sets of contacts designated NORMAL and

a slippery parking area may be difficult to accomplish

RESERVE. Upon failure of the normal contacts, the

and towing may be necessary. Taxiing on the aft gear

reserve set maybe brought into operation by placing the

should not be used to position the helicopter among

switch on the junction box to RESERVE. The junction

other parked aircraft.

box is on the ignition unit next to the heater.

8-70. Engine Shutdown. No unusual problems are

8-61. Heater Overheat Condition. If the HEATER

encountered during engine shutdown as long as the

HOT caution illuminates, proceed as follows:

procedures in section II are adhered to.

CAUTION

8-71. Before Leaving Helicopter. If the helicopter is

to be parked outside for extended periods, maintenance

The heater function switch shall remain ON

personnel should install all protective covers and secure

while performing steps a. through c.

the rotor blades. When ambient temperatures of -18C

and below are expected and the helicopter is to be

Wait two minutes for cooldown.

parked outside,

maintenance personnel should also

remove the battery and store it in a warm area until

HTR START switch - Press.

required for further operation.

c. H E A T E R H O T

caution - Monitor.

The

HEATER HOT caution will not extinguish until

8-72. DESERT AND HOT WEATHER OPERATION.

combustion chamber temperature is

below 177°C

Refer to FM 1-202, Environmental Flight.

and the HTR START switch is pressed.

8-73. General. The reduction in power available and

8-62. Engine Starting. No special cold weather start

the resulting decrease in helicopter performance caused

procedures are required.

by reduced air density is the main consideration during

desert and hot weather operation. Therefore, greater

8-63. Warmup and Ground Tests. Allow the engine

emphasis must be placed on determining performance

and transmission oil pressures and temperatures to

during mission planning.

stabilize prior to takeoff. This will require several

minutes of operation at FLT.

8-74. Preparation for Flight. A normal preflight in-

To prevent unnecessary scratches, allow electrical wind-

spection is to be conducted as described in section II.

shield heating to completely soften frost, snow, or ice

Extra emphasis should be placed on equipment which

before using the windshield wipers.

may be affected by higher temperatures, such as tires,

8-17

TM 55-1520-240-10

seals, and hydraulic components. In addition, check

flown. This is accomplished to prevent the

equipment for signs of deterioration or excessive abra-

cyclic trim actuators from cycling.

sion from blowing dust or sand. Windows and doors

5. Loose equipment - Secure.

should be opened to provide increased ventilation.

6. Safety belts and shoulder harnesses - Tighten.

8-75. Engine Starting. The normal engine starting

procedures in section 11 are to be used.

8-83. In Turbulent Air. The thrust control position,

when adjusted for the airspeeds mentioned above,

8-76. Taxiing. Braking should be kept to a minimum

should be maintained and the attitude indicator should

to prevent overheating. Ground operation in general

be used as the primary pitch instrument. The altimeter

should be kept to a minimum.

and vertical velocity indicator may vary excessively in

turbulence and should not be relied upon. Airspeed

8-77. Takeoff, Climb, Cruise, and Descent. Heli-

may vary as much as 40 knots. By maintaining a constant

copter performance may be reduced; therefore, tech-

thrust control position and a level flight attitude on the

niques should be adjusted accordingly,

attitude indicator, airspeed will remain relatively con-

stant even when erroneous readings are presented by

8-78. Landing. The landing procedures in section II

the airspeed indicator.

apply. Braking should be kept to a minimum to prevent

overheating.

8-84. Flight in Thunderstorms. Flight in or in close

proximity to thunderstorms is to be avoided because of

8-79. Engine Shutdown. It maybe necessary to mo-

the accompanying severe turbulence and restricted vis-

tor the engines if temperature does not decrease below

ibility. If a thunderstorm is inadvertently encountered

350°C. It may not be possible to lower the temperature

during flight, the procedures for flight in turbulent air

to 260°C. If the temperature will not decrease below

are to be followed and the flight path altered to leave

260°C, terminate motoring when the temperature indi-

the area. Should a thunderstorm be encountered during

cation stabilizes.

a night flight, the cockpit dome light should be turned

on with white light selected to minimize the blinding

NOTE

effect of lightning. Refer to chapter 5 for limitations.

Pilots should make an attempt to avoid

motoring periods in excess of 15 seconds.

8-85. ICE AND RAIN.

8-86. Ice. The helicopter is equipped with pitot tube,

8-80. Before Leaving the Aircraft. Leave all win-

AFCS yaw port heating, and windshield anti-icing sys-

dows and doors open

^-to increase ventilation, except

terns to enable safe flight in light icing conditions.

during conditions of blowing dust or sand.

Operation of these systems is described in Chapter 2.

Additional information and specific procedures are also

8-81. TURBULENCE AND THUNDERSTORM OP-

included in this section under Cold Weather Opera-

ERATION.

tions. The greatest damage caused by ice accumulation

is lowered rotor blade efficiency resulting in decreased

8-82. Prior to Entering Turbulent Air.

range and endurance.

If icing is encountered during IMC flight, consideration

must be given to reduced range and endurance due to

To prevent engine overtorque, do not enter

increased fuel consumption. Refer to chapter 5 for

forecast moderate or stronger turbulence

limitations.

with the thrust brake (portion of the CCDA)

inoperative or BARO ALT engaged.

8-87. Exterior Inspection. Refer to paragraph 8-15.

8-88. Taxiing. Taxi at slow speeds to ensure positive

Prior to entering moderate or stronger turbulent air, the

braking action during turns. The forward tilt of the

following should be accomplished:

rotors will cause the helicopter to continue moving

1. BARO ALT switch

- Disengaged.

forward if icy conditions prevent braking.

2. Crew - Alert.

8-89. Before Takeoff. When the takeoff is to be

3. Airspeed

- Adjust as follows:

accomplished into possible icing conditions, the follow-

ing are to be accomplished as part of the Before Takeoff

a. In severe turbulence, decrease

airspeed to

Check.

Vne minus 15

knots or to maximum range,

whichever is slower. (Refer to chapter

7.)

ANTI-ICE switches

- ON. Refer to chapter 5 for

limitations.

b. In moderate

turbulence, decrease airspeed

to Vne minus 10

knots or to maximum range,

8-90. During Flight. Since all of the systems on this

whichever is slower. (Refer to chapter

7.)

helicopter are of the anti-icing rather than the de-icing

4. Longitudinal cyclic trim - Select MAN, then

type, always start systems at least

5 minutes before

adjust both actuators for the airspeed to be

entering a suspect or forecast icing area. In addition,

8-18

TM 55-1520-240-10

engine icing can occur at temperatures above freezing.

with a number of factors. The flight regime, gross

weight, wind direction and velocity, pilot technique,

a. Extended flight in light icing conditions may result

duration of maneuver, salinity of the water, and the

in lateral and vertical vibrations caused by asymmetric

relative density of the salt spray, all have a bearing on

self-shedding of ice. Minor rotor blade damage may

performance deterioration. Intermittent operation in

occur from ice shedding at 10°C and below. One-per-

moderate salt spray conditions could expose the engines

rev lateral vibrations from asymmetric shedding at any

to enough salt spray to cause noticeable performance

temperature may occur. If vibrations are encountered,

deterioration. During prolonged operations (such as

airspeed should be reduced and the aircraft should be

low hovering) in heavier spray conditions, power dete-

flown out of the icing area.

rioration will be apparent and is more critical. Maneu-

b. Extended flight in icing conditions can result in ice

vers such as hovering close to the water in light winds, or

accumulating on the helicopter heater fuel drain. If the

low flights at low speeds will generate maximum rotor

heater shuts down during icing, do not attempt restart

downwash spray conditions. Careful operation, follow-

until ice is removed from the heater intake, exhaust, and

ing the procedures and limitations contained herein, in

heater fuel drain.

strict adherence to the prescribed maintenance proce-

dures when operating in these conditions, should result

8-91. Approach and Landing. Accomplish a normal

in the preservation of rated engine power.

approach and landing; but if icing is present, increased

power will be required. The forward and aft wheels

8-95. Hovering. Hovering over salt water at altitudes

accumulate ice, which can result in the brakes freezing.

that cause concentrated spray into the engine inlets

If icing conditions have been encountered, a zero

results in gradual power deterioration and eventual

forward ground speed landing should be accomplished.

reduction of compressor stall margin. Operation in

these conditions should be avoided or minimized. The

8-92. Rain. It is considered that rain will have no

following procedures are grouped according to wind

detrimental effect on the flight characteristics or per-

conditions. Maximum hovering altitude, consistent with

formance of the helicopter. The windshield wipers

safety and mission accomplishment, is recommended to

should be adjusted to FAST during an instrument

reduce possibility of salt spray ingestion. Prolonged

approach in rain, as rain may present a restriction to

hovering over salt water which results in spray ingestion,

visibility. Pitot heat should be used for flights in rain to

indicated by spray on the windshield, must be avoided.

prevent moisture from accumulating in the pitot tube

The amount of spray observed on the windshield is

and AFCS yaw ports and tubing.

usually the best indication of spray ingestion into the

engine inlets.

8-93. SALT WATER OPERATION.

a. No wind. Hovering in a no-wind condition nor-

8-94. Power Deterioration. Salt spray ingestion in

mally results in a relatively low spray concentration at

turbine engines may result in a loss in performance as

all hovering altitudes.

well as a loss in compressor stall margin. This reduction

b. Light winds (approximately 5 to 16 knots).

Hov-

in stall margin makes the engine susceptible to stalls

ering in these conditions results in the heaviest or most

during acceleration, and, more particularly, under de-

critical spray concentrations. Spray can be minimized by

celeration conditions. As spray is ingested and strikes

heading changes with reference to wind direction and

the compressor blades and stator vanes, salt is depos-

ascertaining minimum spray concentration on wind-

ited. The resulting buildup gradually changes the airfoil

shield.

sections, which in turn affects performance. This dete-

rioration will be noticed as a decrease in torque and an

c. Moderate to heavy winds (15 knots and above).

increase in PTIT for a given N1. Should the deteriora-

Higher winds normally result in the lowest of spray

tion reach the point where the compressor actually

concentration at all hovering altitudes. In these condi-

stalls, PTIT will increase, while N1 and torque will

tions, hovering can be accomplished into the wind.

decrease. The circumstances under which power dete-

rioration may occur during salt water operation vary

8-96. After Flight. Refer to Appendix C.

Change 4

8-19/(8-20 blank)

55-1520-240-10

CHAPTER

EMERGENCY PROCEDURES

SECTION I HELICOPTER SYSTEMS

9-1. Helicopter Systems.

c. The term AUTOROTATE

is defined as adjusting the

flight controls as necessary to establish an autorotational

This section describes helicopter systems emergencies which

descent and landing.

may reasonably be expected to occur and presents the

procedures to be followed. Emergency operation of mission

1. Thrust control -Adjust as required to maintain

equipment is contained in this chapter, insofar as its use

RRPM.

affect safety of flight. Emergency procedures are given in

2. Pedals

- Adjust

as required.

checklist form when applicable. A condensed version of

theses procedures is included in TM 55-1520-240-CL. Refer

3. Cyclic - Adjust as required.

to figure 9-1 and

9-2 for emergency equipment, exits, and

d. The term EMER ENG SHUTDOWN

is defined as

entrance.

engine shutdown

without delay.

Engine shutdown in flight

is usually not an immediate-action item unless a fire exists.

9-2 . Immediate Action Emergency Checks.

Before executing an engine shutdown, identify the affected

engine by checking indications of torque, RRPM, N1, PTIT,

NOTE

engine oil pressure and

714A ENG FAIL Caution.

The urgency of certain emergencies requires

immediate and instinctive action by the pilot.

CAUTION

The most important single consideration is he-

licopter control. All other procedures are subor-

When in-flight shutdown of a malfunctioning

dinate to this requirement. The MASTER CAU-

engine is anticipated, positive identification

TION should be reset after each malfunction to

of the malfunctioning engine must be accom-

allow systems to respond to subsequent mal-

plished to avoid shutting down the wrong

functions. When appropriate, a check of the

engine.

affected PDP for open circuit breakers should be

1. ENG COND

lever - STOP.

accomplished, in some cases this may minimize

or eliminate the emergency. An example of this

2. FIRE PULL

handle

- Pull (engine fire only).

would be an apparent failure of an instrument,

3. AGENT DISCH

switch -As required

(engine

whereas reseting the circuit breaker restores

fire only).

operation. If time permits during a critical

e. The term ABORT START

is defined as engine shut-

emergency, jettison external loads, and lock

down to prevent PTIT from exceeding limits or whenever

shoulder harnesses.

abnormal operation is indicated. If high PTIT was indicated,

Those steps that must be performed

immediately

in an

the engine must be motored to decrease PTIT below 260°C.

emergency procedure

are underlined. These steps must be

1. ENG COND

lever -STOP.

performed without reference to the checklist (CL). When

the situation permits, non-underlined steps will be accom-

2. ENG START

switch -MTR

(if high PTIT is

plished with the use of the CL.

indicated).

9-3. Definition of Emergency Terms.

NOTE

For the purpose of standardization, the following definitions

If a second engine start is to be attempted, wait

shall apply:

at least 15 seconds after the N1 tachometer

indicates zero before attempting start. This will

a. The term LAND AS SOON AS POSSIBLE

is defined

allow sufficient time for fuel to drain from the

as executing a landing to the nearest suitable landing area

combustion chamber.

(e.g., open field) without delay.

(The primary consideration

is to assure the survival of occupants.)

9-4. Emergency Warning Signals and Exits.

b. The term LAND AS SOON AS PRACTICABLE

The helicopter is equipped with an emergency troop alarm

defined as executing a landing at the nearest suitable

and jump light system. The following standard signals will

airfield/heliport.

be used to notify occupants of an emergency situation:

Change

9-1

55-1520-240-10

1. Prepare for ditching, or crash landing -

3 short

will have no effect on any of the helicopter systems as long

rings.

as the RRPM is maintained above the minimum speed. On

the 714A a 1% to 3% NR momentary transient can be

2. Water contact

- Sustained ring.

anticipated. Then NR will automatically recover to the

Emergency equipment, exits, and entrance routes are shown

selected NR.

in figures 9-1 and 9-2. Emergency exit door handles are

b. 712 When one engine fails, rotor speed can be

yellow and black striped. Emergency equipment consists of

expected to drop to as low as 93 percent. Safe RRPM can

seven first aid kits, three hand fire extinguishers, one

usually be regained by using engine beep trim and power

emergency escape axe, and three emergency exit lights.

available of the operating engine.

9-5. After-Emergency Action.

c. If sufficient power is not available, normal RRPM is

regained by lowering the thrust control. Procedures to be

After a malfunction of equipment has occurred, appropriate

followed after engine failure will be governed by the

emergency actions have been taken, and the helicopter is on

altitude and airspeed available for helicopter control and for

the ground, an entry must be made in the Remarks Section

maintaining sufficient RRPM for continued flight and

of DA Form 2408-13, describing the malfunction.

landing. The height-velocity diagram (fig. 9-4 and 9-4.2)

presents the airspeeds and wheel heights from which a safe

9-6. ENGINE.

landing can be made at various GW and temperatures

9-7. Flight Characteristics.

following a S/E failure.

a. If an engine failure occurs, no control problems exist

d. Decrease in thrust after engine failure will vary

unless power from the remaining engine is not sufficient to

with altitude and airspeed at the time of occurrence.

maintain the selected RRPM. If sufficient power is not

For example, thrust must not be decreased when an

available to maintain altitude, descend to an altitude where

engine (or engines) fail at a hover in-ground-effect

single-engine (S/E) flight can be accomplished (fig. 9-3 and

(HIGE); whereas, during cruise flight conditions, alti-

9-4.1 for S/E performance data). The best indications of

tude and airspeed are sufficient for a significant reduc-

engine failure are decreased torque on the failed engine and

tion in thrust, thereby allowing rotor speed to be

a compensating increase in torque on the remaining engine,

maintained in the safe operating range. Following an

accompanied by a droop in RRPM, and a continuing

engine failure, cyclic control is adjusted as necessary to

decrease in N1 speed below 60 percent. An engine failure

A66961

Change 13

Figure

9-1. Emergency Equipment

TM 55-1520-240-10

remain in hover over the desired point or to control airspeed

required airspeed. The Autorotation Approach Corridor,

and flight path in forward flight. Pedal pressure is applied as

figure 9-6 and figure 9-4.1, presents those combinations of

necessary to control aircraft heading.

airspeeds and wheel heights from which a safe autorotative

landing may be made following a second engine failure.

e. Airspeed should be maintained at the optimum for

Autorotative approaches are recommended in the caution

existing conditions for continued flight (S/E failure) or for

area. At high gross weights, the rotor may tend to overspeed

autorotational descent (dual-engine failure). As airspeed

increases above 70 KIAS in autorotation, there is a corre-

and may require thrust application to maintain RPM below

sponding increase in rate of descent (R/D). Airspeed up to

the upper limit. Thrust should never be applied to reduce

100 KIAS or Vne, whichever is slower, will increase glide

RPM for extending glide distance because this reduces

distance but should be avoided at low altitude because the

RPM available for use during touchdown. When both

time available to decelerate is critical. At airspeeds below

engines fail at cruise, proceed as follows:

KIAS, R/D in autorotation increases and glide distance

1. AUTOROTATE.

decreases. Gliding the helicopter in autorotation out-of-trim

will also increase R/D and decrease glide distance

2. External cargo - Jettison.

9-8. Minimum Rate of Descent - Power Off.

3. ALT

switch -

Disengage.

The power off minimum R/D is attained at an indicated

9-11. Single Engine Failure.

airspeed of approximately 70 knots and 100% RRPM (fig.

9-5).

The action taken after one engine fails will depend on

altitude, airspeed, phase of flight, areas available for land-

9-9. Maximum Glide Distance - Power Off.

ing, and S/E capability of the helicopter. Immediately after

The maximum glide distance is attained at an indicated

any engine malfunction, the flight engineer should check

airspeed of

100 knots or Vne, whichever is slower, and

the engine for the possibility of fire. If required, external

100%

RRPM (fig. 9-5).

cargo should be jettisoned as soon as possibile after engine

failure. This will help to prevent damage to the helicopter

9-10. Dual Engine Failur..

during touchdown and will reduce weight and drag, thereby

improving S/E performance.

CAUTION

Thrust control adjustments will depend on altitude at the

Jettison external cargo as soon as possible

time of the engine failure. For example, at (HIGE) below 20

after engine failure. This will help to prevent

feet, maintain thrust control position as the operative engine

damage to the helicopter during touchdown

beep trim is increased. At a hover above 20 feet, thrust

and will reduce weight and drag, thereby

should be lowered slightly to maintain at least 96 percent

improving autorotational performance.

RRPM. If altitude permits, thrust may be lowered suffi-

ciently to maintain normal RRPM.

a. Low Altitude/ Low Airspeed.

When both engines fail

at low altitude and low airspeed, sufficient altitude is not

Cyclic inputs will depend on altitude and airspeed. At a

available to increase RRPM. Establish the best autorota-

(HIGE), the helicopter should be maintained in a hovering

tional airspeed, jettison external cargo (if applicable), and

attitude. In forward flight, at low altitude (below 50 feet),

decelerate effectively prior to touchdown. Initial thrust

when S/E flight is not possible a decelerating attitude should

reduction will vary from no reduction at zero airspeed

be assumed to dissipate airspeed and aid in cushioning the

below 20 feet to full reduction at higher airspeeds and

helicopter. If airspeed is slow and altitude permits, the

altitudes. Attempt to maintain at least 96 percent.

helicopter should be placed in an accelerating attitude of up

to 30° nose-low to gain airspeed as the operative engine

CAUTION

beep trim is increased. This nose-low attitude should not be

used at an extremely low altitude because of reduced

The helicopter must be maneuvered into the

reaction time, R/D, and the response of the helicopter. Any

autorotation approach corridor prior to land-

time the helicopter assumes a decelerating attitude in close

ing to assure a safe outcome of the maneuver.

proximity to the ground, avoid rotating the aft gear into the

b. Cruise. In cruise flights up to Vne, reduce thrust

ground at touchdown.

immediately to full down position to regain RRPM. Adjust

cyclic pressure as necessary to attain and maintain the

Change 13

9-5

TM 55-1520-240-10

Continued flight is not possible:

9-11.1. 714A ENG 1 FAIL or ENG 2 FAIL.

Land as soon as possible.

The ENG 1 FAIL or ENG 2 FAIL caution is illuminated

whenever the engine failure logic within the DECU recog-

9-13. Engine Restart During Flight.

nizes any one of the following:

1. Power turbine shaft failure. N2 is greater than

WARNING

RRPM by more than 3%.

N1 underspeed. N1 speed is below 48%.

Fire detector and extinguishing systems are

not provided for the APU. Crewman must

Engine flameout.

monitor APU area for fire.

Over temperature start abort (Primary mode only).

CAUTION

5. Primary system fail freeze (Primary and Rever-

sionary mode hard faults, FADEC caution is

If abnormal indications are present during

illuminated).

the restart, shut down the engine immedi-

ately.

6 . During normal shutdown as the N1 rpm goes

below 48% the ENG 1 FAIL or ENG 2 FAIL

1. APU - Start.

caution is illuminated and then is turned off 12

2. 712 ENG COND lever (inoperative engine) -

seconds after the N1 rpm drops below 40%.

STOP

2.1

714A ENG COND lever (inoperative engine)

- STOP, then GND.

9-12. Single Engine Failure - Low

FIRE PULL handle - In.

Altitude/Low Airspeed and Cruise.

All FUEL PUMP switches - ON.

If an engine fails under conditions that will permit S/E

flight, thrust 712 engine beep trim must be adjusted as

XFEED switch - As required.

required to maintain safe RRPM. Initial thrust reduction

Starting engine - Perform.

will vary from no reduction at zero airspeed below 20 feet

to a significant reduction at higher altitudes and airspeeds.

7. APU - OFF.

Attempt to maintain at least

96 percent RRPM. If the

helicopter is below the best S/E climb airspeed, forward

9-14. 712 Normal Engine Beep Trim System Fail-

cyclic must be applied to attain that speed. When (HOGE),

ure (High Side) or N2 Governor Failure.

forward cyclic pressure must be applied to attain a nose-low

Fail&e of the normal engine beep trim system to the high

attitude of up to 30° in order to gain airspeed. As airspeed

side may be recognized by increasing torque on the affected

increases to 30 knots, adjust the pitch attitude of the aircraft

engine, decreasing torque on the unaffected engine, an

to accelerate to the best S/E climb speed.

increase in RRPM, and a lack of response of normal engine

beep trim. These indications should be confirmed by ob-

If an engine fails under conditions that

will not permit S/E

serving all the engine instruments.

flight, the procedures will be essentially the same as for

continued flight, except that cyclic pressures are applied to

Controlling RRPM with the ECL must be done smoothly

decelerate the helicopter for touchdown, rather than contin-

and with care. Engine response is much faster and it is

ued acceleration. During deceleration, just prior to touch-

possible to cause the RRPM to exceed limitations or

down, avoid rotating the aft landing gear into the ground.

decrease to the point that the generators will be discon-

nected from the buses. If the thrust control is moved, it is

Continued flight is possible:

necessary to control RRPM with the engine condition lever

1..

Thrust control - Adjust as necessary to main-

and the No.1 & 2 ENGINE BEEP TRIM switch. If a

tain RRPM.

malfunction to the high side occurs, perform the following:

ENGINE BEEP TRIM

switch -

RPM

Thrust control - Adjust as required to maintain

INCREASE as required.

RRPM within limits.

External cargo - Jettison (if required).

ENG COND

lever (affected engine) -

Adjust to

ALT switch -

Disengage.

a position between FLT and GND that will control

RRPM.

Land as soon as practicable.

ENGINE BEEP TRIM

switch NO. 1 & 2 -

6. EMER ENG SHUTDOWN (when conditions

Adjust as required.

permit).

4. Land as soon as practicable

NOTE

9-15. 712 Normal Engine Beep Trim System Fail-

If S/E flight can be maintained, an attempt to

ure (Low Side or Static).

restart the inoperative engine may be made if

there is no evidence of fire or obvious mechani-

Failure of the normal engine beep trim system to the low

cal damage.

side can be recognized by decreasing torque on the affected

9-12

Change 13

TM 55-1520-240-10

engine, increasing torque on the unaffected engine, a loss of

Two different reactions can occur depending if the engine

RRPM, a lack of response to ENGINE BEEP TRIM and N1

with the failed FADEC went into fixed fuel flow at a high

stabilized at or above ground idle (60 to 63% N1). These

fuel flow or a low fuel flow.

indications also accompany an engine failure; therefore,

In a high fuel flow situation, the FADEC on the non

engine instruments must be monitored to determine which

malfunctioning engine may cause the non malfunctioning

event has occurred. A static failure may be recognized by

engine to drop off line in an effort to maintain 100 percent

failure of one or both engines to respond to beep commands

NR (since the failed engine has a high fixed fuel flow).

or may resemble a high or low side failure when the thrust

Conversely, if the failure occurred at a low power setting,

control is lowered or raised

the malfunctioning engine will provide little or no power

If the thrust control is moved with either EMERG ENG

upon demand. These indications must be confirmed by

TRIM AUTO/MANUAL switch in MANUAL, it is neces-

observing the engine instruments display since the non-

sary to control RRPM and torque by use of the appropriate

malfunction engine could have low or high torque in

EMERG ENG TRIM INC or DECR switch. Perform the

comparison to the fixed fuel flow engine.

following:

This fixed fuel flow condition may cause an increase in NR

1. EMERG ENG TRIM

switch (affected engine)

when THRUST CONT lever is reduced. Another indication

- Adjust as required.

would be a split in TQ with upward or downward THRUST

CONT applications.

2. EMERG ENG TRIM AUTO/MANUAL

switch

(affected engine)

- MANUAL.

This fixed fuel flow condition may be capable of providing

3. EMERG ENG TRIM

switch (affected engine)

partial power at THRUST CONT application depending on

- Adjust in coordination with the ENGINE

the power that was required when the system sustained the

BEEP TRIM NO. 1 & 2 switch to normal operat-

hard failure.

ing RRPM and match torque.

Failure of the REV engine control system to a fixed fuel

flow may require the engine to be shutdown at some point

9-15.1. 714A FADEC FAILURES.

before landing to prevent NR overspeed. The ENG COND

lever will be inoperative, therefore unable to modulate

9-15.2. 714A FADEC 1 or FADEC 2 Caution.

engine N1. The FIRE PULL handle or the manual FUEL

VALVE must be used to secure the engine (if desired).

1. FADEC INC-DEC beep switch (affected engine)

- Match TQs.

9-15.5. 714A REV 1 and/or REV 2 (WITH) FADEC

LIGHT ON.

If a malfunction to the high side

2. Reduce rate of THRUST CONT lever change.

occurs, perform the following:

3. Land as soon as practicable.

1. THRUST CONT lever - Adjust.

9-15.3.

714A FADEC 1 and FADEC 2 Cautions.

2. FIRE PULL handle (affected engine) - Pull as

required.

1. FADEC ENG 1 and ENG 2 INC-DEC beep

switches

- Beep to 100 percent, match TQs.

3. NR

- Check 100 percent.

2. Reduce rate of THRUST CONT lever changes.

4. Land as soon as practicable.

3. Land as soon as practicable.

9-15.6.

714A

REV 1 and/or REV 2 (WITHOUT)

FADEC LIGHT ON

9-15.4.

714A

Reversionary System Failures.

1. Land as soon as practical.

NOTE

CAUTION

The aircrew should be alert to the possibility of

abrupt NR changes when operating the FADEC

Do not manually select Reversionary mode

in single or dual engine REV mode (s).

on affected engine as uncommanded power

changes may occur.

NOTE

9-15.7.

714A Torque Measuring System Malfunc-

The following procedure assumes the primary

tions.

and reversionary FADEC modes have failed.

Malfunctions in the torque measuring system can appear as

a frozen indication, a zero torque indication or no indica-

When operating in the reversionary mode and the reversion-

tion. If a torque measuring system malfunction occurs

ary mode sustains a hard fault, REV lor REV 2 caution is

proceed as follows:

active, a failed fixed fuel flow condition may exist. The

ENG COND lever will be inoperative, therefore unable to

1. DC Torque circuit breakers - In.

modulate engine N1. The indications may be a change in

sound, vibration absorbers may detune causing vibration,

2. LOAD SHARE switch - Check. If the switch

and a possible increase in NR when the THRUST CONT

is set to TRQ, proceed to

step 3. If the switch is

lever is reduced.

set to PTIT, proceed to

step 4.

Change 13

9-12.1

TM 55-1520-240-10

NOTE

of an engine to accelerate past 70 percent N1 when ad-

vancing the ENG COND lever to FLT. A sudden high

If the DECU fault code is 88, the DECU has not

torque clutch-engagement may cause severe engine and/

detected a fault in the torque measuring sys-

or drive train damage. A sudden engagement is indicated

tem and will continue to try to match the NO.

by a loud noise and/or a sudden large increase in engine

1 and NO. 2 engine torque. The DECU torque

torque. Should the engine transmission fail to engage,

matching logic will try to increase the low en-

perform the following:

gine’s torque. This will cause a transient rotor

speed excursion possibly up to 103% from an

initial 100% selected condition. The power tur-

WARNING

bine governor will automatically bring the rotor

speed back to 100%. However, a split in actual

Do not shut down both engines simulta-

engine torque will occur as evidenced by PTIT

neously. Maintain RRPM with the engaged

and N1 indicators. If the DECU fault code is A1,

engine until affected engine N1 reaches

the DECU has detected a failure of the torque

zero (0).

measuring system and has automatically

switched to N1 load share.

1. ENG COND lever (affected engine only -

3. Load Share switch - Select PTIT.

STOP.

4. Fuel flow - Monitor. 1896 PPH is equal to

When N1 reaches zero (0):

approximately 100% torque at 100% rotor

2. ENG COND lever (engaged engine) - STOP.

speed.

5. Verify that PTITs are matched.

9-17. Engine Shutdown - Complete Electrical

Failure.

6. Minimize power as practical.

1. FUEL VALVE #1 and #2 ENGINE - CLOSE.

7. Land as soon as practicable.

2. Normal shutdown - Perform.

9-16. Engine Transmission Clutch Failure to En-

gage.

9-18. Engine Shutdown - Condition Lever Failure.

An engine transmission clutch failing to engage is most

Should the engine condition lever fail to shut down or

likely to occur when the engine condition lever is ad-

control an engine, use the following procedure for engine

vanced from GND to FLT or during engine start. The

shutdown.

indications of an engine transmission clutch failing to en-

1. FIRE PULL handle (affected engine) - Pull.

gage are: a loss of torque indication for an engine or

erratic torque indications for an engine or failure of the N1

2. Normal shutdown - Perform.

Change 17

9-12.2

TM 55-1520-240-10

9-19. Engine Shutdown with APU or APU Generator

9-21. ROTOR, TRANSMISSION, AND DRIVE SYS-

Inoperative.

TEMS.

WARNING

CAUTION

When the rotors stop turning, no hydraulic

If an interposer block or rotor blade droop

stop is not in place, the flight engineer will

pressure is available to motor the engines.

notify the pilot in command. All

In the event of internal engine fire when

non-crewmembers will evacuate the

engine motoring cannot be accomplished,

aircraft to a safe position. If possible, crew

use fire extinguishing equipment as nec-

will contact maintenance and attempt to

essary to extinguish the fire.

engage interposer block with a high

Apply external electrical and hydraulic power (if avail-

pressure water stream or prepare aircraft

for shutdown in such a way as to minimize

able) and continue with a normal shutdown. If external

damage to aircraft and components and

electrical and hydraulic power is not available, proceed

prevent injury to personnel. If interposer

as follows:

blocks appear to be in place, the flight

1. No. 2 Engine - Perform a normal shutdown.

engineer will clear the pilot to shut down

the first engine. After the first engine is

2. All unnecessary electrical switches (except

shut down, the flight engineer will observe

BATT switch) - OFF.

the rotor blade tip path of the forward and

3. GEN 1 and 2 switches - OFF.

aft rotor heads. A rotor blade drooping

significantly lower than the other blades

4. ENG COND 1 lever - GND. Wait until PTIT

indicates a missing droop stop. In this

decreases and then begins to increase; then,

case the remaining running engine

move the ENG COND 1 lever to STOP.

condition lever (ECL) should be advanced

5. ENG 1 START switch - MTR until rotors stop

until sufficient rotor RPM is achieved to lift

or PTIT is below 260°C.

rotor blades off droop stops to insure no

blade contact with airframe and

6. Normal shutdown - Perform.

maintenance contacted to prepare aircraft

for an emergency shutdown that will

9-20. Engine Oil - Low Quantity/High Temperature/

minimize damage to aircraft and injury to

High or Low Pressure.

personnel.

A low engine oil quantity condition will be indicated by the

9-22. NO. 1 or NO. 2 ENG XMSN HOT Caution.

lighting of the NO. 1 ENG OIL LOW or NO. 2 ENG OIL

1. EMER ENG SHUTDOWN.

LOW caution light. When either one or both of these

2. Affected engine transmission - Check.

caution lights come on, about 2 quarts of usable oil re-

main in the respective engine oil tank. If one or both of the

3. Land as soon as possible.

caution lights come on, check oil temperature and oil

9-23. Transmission Debris Screen Latches.

pressure indicators (affected engine) for abnormal indi-

Trouble developing in any of the five transmissions may

cations. If the indication on the oil temperature indicator

be indicated by a tripped latch indicator. This information

is high or the indication on the oil pressure indicator ex-

will be presented on the flight engineer’s MAINTE-

ceeds limits, high or low, perform the following:

NANCE PANEL but will not be shown in the cockpit. If an

indicator trips:

1. If engine power is required for flight:

FWD, COMB, or AFT DEBRIS SCREEN indicator:

Land as soon as possible.

F RESET/GND/TEST switch - RESET.

2. If engine power is NOT required for flight:

If indicator does not reset:

a. ENGINE CONDITION lever (affected en-

Land as soon as possible.

gine) - STOP.

LEFT or RIGHT DEBRIS SCREEN indicator:

b. Land as soon as practicable.

F RESET/GND/TEST switch - RESET.

9-20.1

Engine Chip Detector Caution Light ON.

If indicator does not reset and engine power is not re-

quired then:

If either NO. 1 or NO. 2 ENG CHIP DET caution light

comes on, perform the following:

1. EMER ENG SHUTDOWN.

2. Land as soon as practicable.

1. If engine power is required for flight:

If engine power is required:

Land as soon as possible.

2. If engine power is NOT required for flight:

9-24. Transmission Low Oil Pressure or High Tem-

a. ENGINE CONDITION lever (affected en-

perature Indications.

gine) - STOP.

Developing trouble in the transmissions can be identi-

b. Land as soon as practicable.

fied by high oil temperature or low oil pressure, as

Change 17

9-13

55-1520-240-10

indicated by transmission temperatLEFT o

RIGHT

tors and cautions. If an abnormal temperature or pressure

Engine power is not required:

indication develops, closely monitor the caution capsules.

1.MER ENG SHUTDOWN.

The XMSN OIL PRESS (main or aux) and XMSN OIL HOT

2. Land as soon as practicable.

caution capsules operate independently of the pressure and

temperature indicating system and Engineepowernisrequired:a low pres-

sure or high temperature conditionLand as soon as possible.

information may be obtained by the flight engineer checking

Malfunctions.

the MAINTENANCE PANEL. The transmi9-28.1.nTorqueMeasuringtSystem

and pressure selector switches shaMalfunctions in the torque measuring sy

mining the defective transmission.the torquemeter as fluctuations, zero t

gish movement, indications that are out

9-25.

XMSN OIL PRESS Caution.

If the XMSN OIL

tionary indication. Fluctuations in tor

PRESS caution capsule comes on. the following actions

indicative of

an electrical malfunction

should be taken:

this occurs. proceed as follows:

FWD

orOMB (MIX):

1. AC and DC TORQUE circuit breakers

1. Al

- Descend to minimum safe a2.N1sde.Monitor when power changes a

2. Airspeed - 100 KIAS or Vne whichinsuring power

outputs are matched.

3.Fuel flow indicator - Monitor for

3. Land as soon as practicable.

flows.

AFT or AFT SHAFT (confirm AFT SHAFT with flight

4.Land as soon as practicable.

engineer):

9-29. FIRE.

Land as soon as possible.

The safety of helicopter occupants is

LEFT

RIGHT

ation when fire occurs; therefore, it i

Engine power is not required.

effort be made by the flight crew to pu

1. EMER ENG SHUTDOWN.

ground, it is essential that engines b

passengers be evacuated, and fire figh

2. Land as soon as practicable.

ately. If the

rborne when fire occurs. the

Engine power

is required:

important single action that

and

Land as soon as possible.

as soon as possible. Whether on the ground or inf

mandatory cockit windows, air control

9-26.

XMSN OIL PRESS and XMSN AUX OIL

cockpit air kno

to prevent smoke enteri

PRESS or XMSN CHIP DET Caution.

cockpit, unless the smoke and fume eli

Land as soon as possible.

has been eIncflight the pilot should

smoke and fume elimination

to pre-

9-27.

XMSN AUX OIL PRESS Caution.

If the

vent smoke and fumes from entering the

XMSN AUX OIL PRESS caution capsule comes on, the fol-

guishers should be used to control or e

lowing actions should be taken:

MAIN XMSN (FWD, COMB (MM), or AFT)

Main transmission oil pressure and temperature are

Use fire extinguisher only in well-ventilated

abnormal:

areas because the toxic fumes of the extin-

Land as soon as possible.

guisher agent can cause injury.

Main transmission oil pressure and temperature are

normal:

9-30. ENGINE HOT START.

A hot start will

Land as soon as practicable.

detected by a rapid and abnormal rise

observing flames and black smoke comin

9-28.

XMSN OIL HOT Caution.

If the XMSN OIL

tail cone. Complete the following on th

HOT caution capsule comes on, the following actions should

be taken:

1. ABORT START.

FWD

orOMB (MIX):

Land as soon as possible.

9-30.1.

RESIDUAL FIRE DURING SHUTDOWN.

AFT transmission is indicated:

residual engine fire may occur during s

Electrical load - Reduce as much as possresidual fuel igniting in the combustio

2. Land as soon as possible.

9-14

Change

TM 55-1520-240-10

After landing:

EMER ENG SHUTDOWN.

5. RAMP EMER - As required.

9-33. Engine Compartment, Fuselage, or Electri-

cal Fire - Ground.

NOTE

EMER ENG SHUTDOWN.

The combination of steps 2, 3, a

2. APU switcOFF

(if operating).

evacuates the cockpit and forwa

3. BATT

switcO

FF.

smoke and fumes at airspeeds abo

Opening the cargo loading ramp e

9-34. Electrical Fire

- Flight. Before shutting off all

main cabin. With items in steps

electrical power, the pilot must consider the equipment that

opened, intensification of a smol

is essential to the current flight regime; e.g. flight instru-

occur. If the source of the fi

ments, flight control

anding as soon

determined, close the cargo load

possible cannot be made, defective circuits may be

keep the pilots windows and the

isolated by selectively turning off electrical equipment

the main cabin door open. This w

and/or pulling out circuit breakers.

pilots to see the instrument pan

references for landing

A dual engine flameout may occur if both

6. Copilot’s sliding window

- C

generator switches are turned off above 6,000

feet PA. All fuel boost pumps will be inop-

7. NVG curtain

- Open (if appli

erative.

9-36. FUEL SYSTEM.

1. Airspeed - 100 KIAS or Vne whichever is

9-37. Aux Fuel Pump Failure.

slower.

An auxiliary fuel pump failure will

NOTE

PRESS indicating light, on the FUE

LCT and DASH actuators will illuminating and/or the fuel quanti

grammed at the airspeed at whicremaining at the

same level. Should

were turned off. Normal enginefollows:disabled

when generators are turned off.

1. FUEL QUANTITY selector switc

2. GEN 1 and 2

swit

-OFF.

If one or both auxiliary fuel tanks have fuel remaining:

Land as soon as possible.

2. AC-DC FUEL PUMP circuit brea

After landing:

in.

EMER ENG SHUTDOWN.

3. FWD and AFT AUX FUEL PUMP

5. BATT

switcO

FF.

(affected side)

- OFF.

9-35. Smoke and Fume Elimination.

4. AUX FUEL PUMP switch - ON (e

with fuel remaining).

1. Airspeed - Above 60 KIAS.

2. Pilot’s sliding window - Open.

If AUX PRESS indicating light remains on:

Helicopter attitude - Yaw left, one half to one

5. AUX FUEL PUMP switch(es)

(

ball width on turn and slip indicator.pump(s)

)

- OFF. Monitor FUEL

4. Upper half of main cabin door - Open.

indicator for the affected tan

6. AUX FUEL PUMP switch(es)

- O

tive pumps or Off for inoperat

The cargo ramp can be opened or closed

9-38. Fuel Venting.

either manually by the flight engineer using

the lever on the ramp control valve or elec-

Fuel venting from either main tank

trically by the pilot using the RAMP EMER

bility of fuel cell overpressurizat

control switch on the overhead HYD panel. If

1. AUX FUEL PUMP switches (affected side) -

the flight engineer is unable to manually

OFF.

position the ramp, the pilot should attempt to

check that the ramp is clear of personnel and

2. Main tank (affected side)

equipment before opening or closing it. Un-

When 1,000 pounds of fuel remain:

announced opening or closing of the ramp

may lead to injury to personnel, or damage to

3. AUX FUEL PUMP switches - ON

equipment.

quantity).

Change

9-15

TM 55-1520-240-10

When tank quantity reaches 1,600 pounds:

If any other system caution comes on or a system is lost, a

bus tie does not exists. The primary caution segment lights

4. AUX FUEL PUMP switches - OFF.

to look for in determmmg whether or not a bus tie exists are

5. Steps 2 through 4 -

Repeat until auxiliary tanks

L and R FUEL PRESS, NO.1 and NO.2 RECT OFF, and

are empty.

NO.1 AND NO.2 AFCS OFF.

9-39. L or R FUEL PRESS Caution.

If no bus tie exists and a generator cannot be restored:

If both main tank fuel pumps fail, fuel will be drawn from

Land as soon as possible.

the main tanks as long as the helicopter is operated below

9-44. NO. 1 and NO. 2 GEN OFF Cautions.

6,000 feet pressure altitude. If the L or R FUEL PRESS

caution comes on.

Should both generators fail, both transformer-rectifiers will

XFEED

switch - OPEN

(above 6000 feet PA).

also be disabled. This condition will be indicated by loss of

both AFCS (which can result in abrupt attitude changes) the

FUEL PUMP(S) circuit breakers - Check in.

lighting of both AFCS OFF, GEN OFF, and RECT OFF

caution. Since there will be a loss of all primary attitude,

Pump(s) are operational -Proceed with step 3.

instrument, navigation, and stabilization systems, the pri-

Pump(s)

are not operational-Proceed with step

mary concern is to restore electrical power. The only

3. XFEED switch - CLOSED.

electrical power available will be 24-volt DC from the

battery.

4. FUEL PUMP switches - OFF (inoperative

pump(s)).

CAUTION

9-40. Fuel Low Caution.

If both generators fail, the main tank boost

If a L FUEL LOW or R FUEL LOW caution comes on,

pumps will be inoperative. If flight is con-

perform the following:

ducted above 6,000 feet PA, descend below

6,000 feet PA as soon as possible to avoid a

1. Fuel quantity -

Check individual tanks.

dual engine flameout. If applicable, reduce

2. XFEED switch - As required.

airspeed to 100 KIAS or Vne, whichever is

slower.

712 Also all normal beep trim func-

3. Land as soon as practicable.

tions will be inoperative. EMERG ENG

TRIM switch for both engines should be

9-41. FUEL LOW and FUEL PRESS Cautions.

placed to manual. The control of engine RPM

If the FUEL LOW and FUEL PRESS cautions come on

will be accomplished via the EMERG ENG

perform the following:

TRIM 1 and 2 switches. LCT and DASH

actuators will remain programmed at the

airspeed at which the generators failed.

WARNING

If both generators fail, perform the following:

Failure of main tank fuel boost pumps with

the crossfeed open and a fuel low condition

1. AFCS SYSTEM SEL

switch -

OFF.

may result in a dual engine flameout. Nose

2. PDPs -

Check circuit breakers and gang bar

low attitude should be avoided.

down.

1. XFEED - CLOSED.

3. Each GEN

switch -

OFF RESET,

then ON.

2. Land as soon as Possible.

Electrical power is restored (from either generator):

9-42. ELECTRICAL SYSTEM.

1. PDP’s -

Gang Bar Up.

2. Land as soon as practicable.

9-43. NO. 1 or NO. 2 GEN OFF Caution.

Electrical power is not restored:

NOTE

1. APU - Start.

If either an AC or DC system fails with no bus

tie, the hydraulic oil cooler fans will not func-

2. APU GEN - ON.

tion.

3. Land as soon as possible.

If only the NO. 1 or NO. 2 GEN OFF caution is illuminated,

a bus exists.

NOTE

Regardless of which condition exists, (one or

1. GEN switch -

OFF RESET, then ON.

both main generators inoperative) the defective

If the caution remains on:

generator(s) must be left OFF. If the fault is

cleared and power is restored and a generator

2. GEN switch - OFF.

switch was unintentionally left ON unantici-

3. Land as soon as practicable.

pated transients in the helicopter may occur.

9-16

Change 13

TM 55-1520-240-10

9-46. NO. 1 and NO. 2 RECT OFF Cautions

1. PWR XFER 1 and 2 switch (affected system) -

ON.

When both transformer-rectifiers (TR) fail, all equipment

on the No. 1 and No. 2 DC buses will be disabled.

MAINTENANCE PANEL - Monitor.

Equipment which will be lost includes all fuel boost pumps,

3. Land as soon as possible.

both AFCS, accompanied by abrupt attitude change, and

both torque indicators.

712

Normal engine beep trim is

High fluid temperature is evident:

also disabled, therefore, changes in power settings

Land as soon as possible.

should be minimized. The only source of DC power is the

battery.

9-51. NO. 1 and NO. 2 HYD FLT CONTR Caution.

CAUTION

If both hydraulic systems fail, flight controls cannot be

If both transformer rectifiers have failed, the

moved. In addition, the NO. 1 and NO. 2 AFCS-OFF

main tank boost pumps will be inoperative. If

caution will illuminate. Both AFCS systems must be

flight is conducted above 6,000 feet PA, a

turned OFF as soon as possible.

descent below 6,000 feet PA must be initiated

as soon as possible to avoid a dual engine

1. PWR XFER 1 and 2 switches - ON.

flameout. If applicable, airspeed should be

Land as soon as possible.

reduced to 100 KIAS or Vne, whichever is

slower. LCT and DASH actuators will remain

9-52. UTIL HYD SYS Caution.

programed at the airspeed at which the trans-

Depending upon the nature and location of the system

former rectifiers failed.

712

All normal engine

failure, it may not be possible to operate the following

beep trim functions will be inoperative. The

items of equipment: APU, engine starters, ramp and

control of engine RPM will be accomplished

cargo door, wheel brakes, swivel locks, power steering,

via the EMERG ENG TRIM 1 and 2 switches

cargo hook, PTUs and winch. Should a failure occur in any

once the EMERG ENG TRIM guarded switch is

of these subsystems:

at MANUAL.

If both transformer rectifiers fail, perform the following:

Fluid loss is evident:

1. AFCS SYSTEMS SEL switch - OFF.

1. Isolation switch - OFF.

2. PDPs - Check circuit breakers and gang bars

2. Land as soon as possible.

down.

3. DC equipment not required - OFF or pull out

High fluid temperatures is evident:

circuit breakers.

Land as soon as possible.

4. Land as soon as possible.

9-47. BATT SYS MAL Caution.

Fluid loss is not evident:

1. BATT CHGR circuit breaker - Out, then in.

1. APU - Start.

If the BATT SYS MAL caution remains on:

Land as soon as practicable.

2. BATT switch - OFF.

3. MAINTENANCE PANEL - Monitor.

9-48. HYDRAULIC SYSTEMS.

9-53. Emergency Descent.

9-49. Hydraulic System.

CAUTION

WARNING

In executing any emergency descent, regard-

The power transfer pumps were designed for

less less of energy power available, it is

ground checkout of the flight control system

imperative that the helicopter be maneuvered

and have the capacity to pressurize the sys-

into a position from which a survivable land-

tem for gentle maneuvers only. Rapid control

ing can be accomplished. Transition from the

inputs must be avoided to preclude upper

following descent techniques into an

boost actuator stalling (binding) and/or jam

appropriate landing attitude / airpseed / R/D

button extensions. Use of the power transfer

should begin prior to descending below 600

pumps in flight is restricted to these emer-

fee AGL. The emergency descent procedures

gency conditions only.

below will result in R/D which exceed the

9-50. NO. 1 or NO. 2 HYD FLT CONTR Caution.

rates displayed on the VSI.

Fluid loss is evident:

An emergency descent is a maximum performance

Land as soon as possible.

maneuver in which damage to the helicopter or power

Fluid loss is not evident:

plants must be considered secondary to getting the

9-17

Change 16

55-1520-240-10

helicopter on the ground. No one proc4. RecoveInit

iate at

600

feet AGL.

considered the best for all given situatHelicopter should be returned to win

must consider his flight profile in selecting the emer-

9-54. Autorotative Landing.

gency descent procedure he will execute. RRPM greater

than 102 percent significantly increaa. An autorotative

landing will be accom

tion and should serve as a good RRPMfailure of both

engines. Maintain speed at

maneuver. The following techniquesminimum (R/D) airspeed in autorotation w

greatest IUD from higher altitude.

Maintain RRPM

108

percent by adjusting thru

as necessary. Do not allow RRP

High Speed Straight Ah

his procedure

percent prior to deceleration for touchdo

produces the highest (R/D) but also produces high

airspeeds which must be dissipated priob. At approx50 toa75

elf

eet above ground level.

actual touchdown area may vary froapply aft cyclic control as nec

0°

touchdown point due to the glide annose-high attitude) to initiate a smooth

the initial deceleration to reduce Maintain alinement of the helicopter wit

by application of pedals and cyclic co

1. Thrust

- Lower. Adjust RRareao

thrust as required to prevent RRPM from

maintain appro

104

percent.

above the maximum.

2. Airs

- Adjust (appr130

c. At approximately 15 feet aft gear

KIAS)

sufficient thrust to slow the R/D, assis

3. Recove

nitiate at

600

feet AGL

and effect a smooth touchdown in ETL. The

and decele

70-80 KIAS

to enter tthrust applied and the rate at which it

autorotative corridor.

vary depending upon the wind, load, and

encing factors. Maintain the landing att

NOTE

ble, with cyclic and thrust until forw

Allowing the RRPM to increase dceased,e-

then smoothly lower thrust until

celeration will reduce the fllanding gear

touches the ground. Apply

which will occur when the decelrequired.is

initiated.

d. Whenever a touchdown into the wind u

controlled conditions cannot be made, exec

ing. It is better to perform a

Out-of-Trim DT

is procedure places thwind land

ter in a high R/D and allows simultaing, which can be

executed from sufficie

smoke and fume elimination procedurstop drift and reduce the R/D, than to c

allows good landing area predictabilinto

the wind with the great possibility o

and damage to the helicopter. Decelerate t

1.Thrust control

- Lower. Adjust RRPM to

at the same altitude as though the hel

maintain appro

104

percent.

making the entire approach into the wind.

Airspeed - Adjust to maintain approximately

e. Stop all drift and perform the initia

100 KIAS.

the upwind aft landing gear. In a strong w

Trim- Adjust cyclic and pedalnecessary to hold the helicopter in what i

minimum

ne ball width out of tslip by cross control.

righ (left pedal forward) equivalent to a bank

f. After touchdown, allow the helicopter

angle of appr

8 to 10

degrees rigth

e other landing gear. Perform the grou

and a zero turn rate.

same manner as a landing made into the win

4.Recover

Initiate at

600

feet AGL.

ve.

retrim the ball to centered f9-55. Landing With One Engine Inoperati

airspeed to app

70 KIAS

When committed to a S/E landing, it is

possible to terminate the approach at a ho

Low Speed Maneuvering

aneuvering the heli-

it is recommended that a running landi

copter in steep turns as described below should allow

ates on the ground

the pilot to fly the helicopter ovproach which termin

allow.

during the descent, observe his areaterrain conditions

down, and make adjustments as required.

9-56. Landing in Trees.

Thrust control

- Lower. Adjust RRPM to

External cargo must be jettisoned as soon

maintain appro

102

percent.

a landing in trees is imminent, it IS impo

Airspe-dAdjust airspeed

0 to

forward motion of the helicopter before

90 KIAS.

trees.

Bank ang

Adjust as required. Bank angles

Power on:

of up

0 degrees will result in the desired

rates-of-descent.

1.pproach to a hover - 5 to 10 feet.

9-18

TM 55-1520-240-10

2. EMER ENG SHUTDOWN.

operating range by adjusting the thrust as necessary. At

approximately

100 feet above the water, perform a

3. AUTOROTATE.

gradual longitudinal flare. Allow the RRPM to increase

Power off

to the upper limit so that maximum benefit can be

AUTOROTATE.

gained from the inertia to cushion the touchdown.

b. At approximately

30 feet above the water, the final

9-57. Emergency Entrance.

attitude should be adjusted, not to exceed

20° nose-up.

a. Access to the cockpit is through the pilot and

An excessive nose-up attitude will reduce the clearance

copilot jettisonable doors. (Figure 9-2.)

between the water and the aft rotor blades and concen-

b. Entry to the cargo compartment can be accom-

trate impact forces on the aft fuselage.

plished by opening the cabin door, upper cabin door

c. R/D should be the minimum attainable

at water

escape hatch, cabin escape hatch, ramp escape hatch,

entry and must be considered regardless of water-entry

and cutout panels. All escape hatches can be opened by

speed. The water entry speed should be as slow as

pulling out the yellow tab and pushing out the panels.

possible without sacrificing helicopter control.

c. Entry to the aft cargo compartment maybe made

d. Helicopter attitude at water entry is very important

by manually positioning the ramp control (exterior

and relates directly to water-entry speed. At zero and up

access to the open position.

to 30 knots, the pitch attitude at water entry is dictated

primarily by the clearance between the water and the aft

9-58. Ditching.

rotor blades and should not exceed

20° nose-up.

Entry

There is sufficient buoyancy and lateral righting mo-

speeds up to approximately 40 knots require a pitch

ment to remain afloat and upright for a sufficient length

attitude of approximately

15° to prevent high concen-

of time to permit the passengers and crew safe egress.

trated impact loads on the extreme aft bottom of the

Refer to figure 9-7 for desired ditching exits for clearing

fuselage. However, it is also important not to allow the

of passengers and crew.

pitch attitude to become less than approximately

5° at

the higher water-entry speeds since there is a possibility

9-59. Ditching - Power ON.

of breaking the lower nose enclosure plastic panels.

If ditching is to be accomplished while power is still

available, plan the approach so that the final descent is

e. The actual touchdown on the water will probably

made at

90° to the primary wave pattern and terminates

be governed by one of the following conditions.

in a hover 5 to 10 feet above the water. When stabilized

(1) High wind and rough water.

Use thrust as

in hover, discharge the passengers or wait until the

necessary to minimize R/D at water entry. Do

helicopter is in the water and the rotors have stopped

not hesitate to use the remaining thrust at

turning. If ditching becomes necessary, proceed as

water entry if the R/D is judged to be exces-

follows:

sive.

1. Land away from personnel in the water.

(2) Low wind and calm water.

Follow the proce-

2. EMER ENG SHUTDOWN.

dure above to the point of the deceleration.

Reduce speed to approximately

40 knots and

9-60. Ditching - Power OFF.

then establish a nose-up attitude of approxi-

a. Maintain the desired airspeed at or above the

mately

5° to 10°. Just prior to water entry,

minimum R/D airspeed and RRPM in the normal

increase thrust to cushion the aft landing gear

Figure 9-7. Ditching Exits

9-19

TM 55-1520-240-10

contact with water. Attempt to have the R/D

forward gear touch the ground, the aircraft will tend to

as low as possible when using this technique.

accelerate more than normal. Continue to apply brakes

As the helicopter decelerates, attempt to

as necessary to prevent forward movement. If the

hold the nose out of the water. As the speed

helicopter is taxied with the actuators failed in the

diminishes to 10 knots or less, lower the

extend position, use minimum control applications and

thrust control smoothly and return the con-

adjust the thrust control at the ground detent or higher.

trols to neutral. The helicopter does not

There is an increased susceptibility to droop-stop pound-

display any tendency to pitch down upon

ing with this condition.

water entry. Also, the aft landing gear acts to

create a decelerating force on the water. If

9-63. Single AFCS Failure - Both Selected.

ditching becomes necessary:

A malfunction of the AFCS can usually be detected by

AUTOROTATE.

an abrupt attitude change (hardover) or unusual oscil-

lations in one or more of the flight control axes or by

9-61. FLIGHT CONTROLS.

lighting of the NO. 1 or NO, 2 AFCS OFF caution. If

flight is conducted at low altitude such as contour or

9-62. Longitudinal Cyclic Trim (LCT) System Fail-

NOE, a climb to higher altitude must be initiated before

ure.

the pilot attempts isolation of the defective system.

Should the system fail during cruise, with the cyclic trim

1. Airspeed

- Reduce

to 100 KIAS or Vne,

system programed for maximum forward tilt of the

whichever is slower.

rotors, an abnormal nose-up attitude will result with

2. Altitude - Adjust as required.

decreasing airspeed. Should one or both cyclic actuators

fail in full retract position, airspeed must be limited

NOTE

according to Vne for retracted longitudinal cyclic trim.

With both LCTs partially or fully retracted, maintain

A hardover in the opposite direction may

below Vne and if failure occurs extended, maintain

occur when the malfunctioning AFCS is

airspeed at or above

60 KIAS

or until the approach to

turned off and the functioning AFCS reacts

landing. Should the longitudinal cyclic trim system fail,

on the flight controls.

perform the following:

CYCLIC TRIM circuit breakers -

In. If cyclic trim

3. AFCS SYSTEM SEL switch - Isolate defec-

operation is not restored, proceed with the procedures

tive system. Turn NO. 1 ON, if not isolated,

below for AUTO or MANUAL modes of operation.

turn NO. 2 ON.

If in AUTO mode:

If system is not isolated:

1. Airspeed - Adjust.

AFCS SYS SEL

switch

- OFF.

2. CYCLIC TRIM switch - MANUAL.

9-64. Dual AFCS Failure.

3. FWD and AFT CYCLIC TRIM switches -

AFCS SYSTEM SEL

switch

- OFF.

Adjust for airspeed.

If IMC:

If LCT operation

is not indicated:

Land as soon as practicable.

FWD and AFT CYCLIC TRIM switches -

RET for 30 seconds, before landing.

9-65. Vertical Gyro (VGI) Malfunction.

If in MANUAL mode:

A vertical gyro malfunction will be indicated by an

1. Airspeed - Adjust.

attitude indicator failure, an AFCS OFF caution, and

attitude transients. If a vertical gyro failure occurs,

2. CYCLIC TRIM switch - AUTO.

proceed as follows:

If normal LCT operation

is not indicated:

1. CYCLIC TRIM switch - MANUAL.

2. FWD and AFT CYCLIC TRIM switches -

Failure of the No. 1 vertical gyro with alti-

RET both LCTs for 30 seconds before landing.

tude hold engaged may result in an altitude

runaway. If this occurs, disengage ALT

If both actuators are retracted, the landing will be

HOLD.

normal. If one or both actuators fail in extended

position, the pitch attitude of the helicopter will be

higher than normal during the approach and will be

dependent upon the amount of actuator extension at

the time of the failure. Execute a shallow approach to a

Failure of a vertical gyro results in loss of its

hover or to the ground with a normal touchdown,

associated AFCS and should be treated as a

avoiding large cyclic changes. When the aft gear are on

single AFCS failure.

the ground, apply brakes and lower the nose. As the

9-20

TM 55-1520-240-10

SECTION II MISSION EQUIPMENT

9-68. ARMAMENT.

9-69. Armament Subsystems - M24 and M41.

Primary Method.

CARGO HOOK EMERG switch - REL ALL.

DUAL HOOK FAULT

Do not retract the bolt assembly immediately

when a hangfire or cook-off is suspected. A

Alternate Method.

Helicopter equipped with

forward and

hangfire will normally occur within 5 sec-

aft emergency release lever:

onds from the time the primer is struck. A

cook-off will normally occur after 10 seconds

F 1. Mid hook emergency release handle (D ring)

of contact with the chamber of a hot barrel.

- Pull.

If 150 cartridges are fired in a 2-minute

F 2. Forward and aft hook release lever - Pull aft.

period, the barrel will be hot enough to

produce a cook-off.

NOTE

If the forward and/or aft hooks did not open

Misfire:

because of sling slack, apply a slight amount

F 1. Weapon - Point at safe area.

of thrust to load the hook(s) and force open.

F 2. Bolt - Retract, remove cartridge.

DUAL HOOK FAULT

NOTE

Keep cartridge separate from other ammu-

Alternate Method.

Helicopters equipped with

forward,

nition until it has been determined whether

center and aft emergency release lever.

the catrridge or the firing mechanism was at

Forward, center, and aft hook release lever -

fault. If the cartridge was at fault, it will be

Pull aft.

retained separate from other cartridges until

disposed of. If examination reveals that the

NOTE

firing mechanism was at fault, the cartridge

may be reloaded and fired.

If the forward and/or aft hooks did not open

because of sling slack, apply a slight amount

of thrust to load the hook(s) and force open.

Runaway Gun:

Break the ammunition feed belt.

9-72. Hoist.

9-70. CARGO.

9-71. Jettisoning External Cargo.

Personnel must remain aft of the rescue

hatch and face away from the cable cutter.

The hoist cable may whip forward when it is

If a DUAL HOOK FAULT caution exists,

cut and particles may be ejected from the

normal and emergency release capability for

cable cutter.

the forward and aft hook may be lost. Use the

manual emergency release system only. Re-

lease the center hook first, (if the helicopter

1. Personnel - Clear

is not equipped with triple release mecha-

nism) if it loaded or safety sling is attached.

2. CABLE CUTTER switch - ON.

9-22

TM 55-1520-240-10

9-73

ERFS II and FARE

CAUTION

9-74

Failure of Fuel Quantity Gauge.

There is no gauge on board the aircraft to

Remove filler cap from filler opening and look into

provide measurements of GPM or PSIG. The

tank. Using a explosion proof flashlight or other sealed

rate at which fuel is transferred from the

beam light source locate fuel tabs which are attached to

ERFS II tanks to the Helicopter main tanks is

inside of column module at calibrated heights, in

20 GPM. The rate at which fuel is transferred

increments of 1/4, 1/2, and 3/4. Any tab covered with fuel

from the ERFS II tanks using the FARE pump

will normally not be visible.

and standard FARE transfer hose assembly is

84 to 88 GPM. The FARE pump is rated at 120

9-75

F No or Slow Fuel Transfer to the Main

GPM. Suction defueling pressure should not

Tanks.

exceed -11 PSIG. Do not exceed 5 PSI except

1. Manually operated fuel/defuel valve-Check

in extreme emergency. The ERFS II outer

CLOSED.

container is expected to fail at 10 PSI or

greater. The crash resistant bladder will

2. Unisex couplings-Check open.

prevent fuel spillage and fuel can still be

3. Breakaway valves-Check open and for fracture.

transferred.

4. Pumps-Check for operation.

6. FARE valve control handle OFF LOAD Position.

5. Tank circuit breakers on FUEL CONTROL PAN-

7. FARE pump-ON.

EL-Check reset in.

8. ERFS II tank manually operated fuel/defuel

6. Ensure vent lines connected.

valve-OPEN.

9-76

F IN FLIGHT Emergency ERFS II Fuel

9. Once ERFS II tank empties, tank fuel manifold

Transfer to Main Tanks.

“T” coupling-CLOSE.

10. Next ERFS II tank fuel manifold “T” coupling-

Using the FARE pump:

OPEN.

1. FARE pump module to rear most ERFS II tank-

11. Next/remaining ERFS II tank manually operated

Install.

fuel/defuel valve-OPEN.

2. STA 380 fuel transfer hose to rear most ERFS II

12. Once ERFS II tank empties, tank fuel manifold

tank, fuel manifold hose-Disconnect.

“T” coupling-CLOSE.

3. Rear most ERFS II tank fuel manifold hose cou-

13. FARE pump-OFF.

pling to FARE pump inlet (Top) coupling-Con-

9-77

F FARE Pump Failure During Ground

nect.

FARE Refueling Operation.

4. FARE pump module outlet (lower) coupling to

1. Filters-Remove.

STA 380 fuel transfer hose-Connect.

2. Overwing nozzle-Install and use.

NOTE

3. Manually operated fuel/defuel valves-OPEN.

Before FARE fuel transfer begins, a path from

the desired ERFS II tank to the helicopter main

NOTE

tanks must be established and the fuel should

If three ERFS II tanks are installed and all the

be transferred from only one tank at a time.

in-tank pumps are on, a 60 gallon per minute

rate can be achieved.

5. “T” couplings on ERFS II tanks not being trans-

ferred-CLOSE.

4. ERFS II tank pumps-ON.

Change 14

9-23/(9-24 blank)

TM 55-1520-240-10

APPENDIX A

REFERENCES

This appendix contains a list of official publications referenced in this manual and available to and required by CH-47D

helicopter operating activities. The publications listed are directly related to flight operation and maintenance of CH-47D

helicopters.

AR 70-50

Designating and Naming Military Aircraft, Rockets, and Guided Missiles

AR 95-1

Army Aviation - General Provisions and Flight Regulations

AR 95-3

Aviation - General Provisions, Training, Standardization, and Resource

Management

AR 385-40

Accident Reporting and Records

DA PAM 738-751

The Army Maintenance Management System - Aviation (TAMMS-A)

FM 1-202

Environmental Flight

FM 1-230

Meteorology for Army Aviation

FM 1-240

Instrument Flying and Navigation for Army Aviators

FM 1-513

Tactics, Techniques, and Procedures for Aerial Recovery of Aircraft

FM 55-450-3/-4/-5

Multiservice Helicopter External Air Transport

FM 55450-2

Helicopter Internal Loads

TB 55-1500-334-25

Conversion of Aircraft to Fire Resistant Hydraulic Fluid

TB 55-9150-200-24

Engine and Transmission Oils, Fuels, and Additives for Army Aircraft

TM 1-1500-250-23

Technical Manual Aviation Unit and Aviation Intermediate Maintenance for

General Tie-Down and Mooring on all Series Army Models AH-64, UH-60,

CH47, UH-1, AH-1, OH-58 Helicopters

TM 9-1005-224-10

Machine Gun, 7.62 MM, M60

TM 11-5810-262-OP

Operating Procedures for Cryptographic Speech Equipment TSEC/KY-58

TM 11-5810-281-OP

Operating Procedures for Cryptographic Speech Equipment TSEC/KY-75

TM 11-5841-294-12

Operator and Aviation Unit Maintenance Manual for Radar Signal Detecting Set

AN/APR-39A(V)1

TM 11-5855-300-10

Operating Procedures for Heads Up Display AN/AVS-7

TM 11-5895-1199-12

Operator’s and Organizational Maintenance for Mark XII IFF System

(AN/APX-100, AN/APX-72)

TM 38-250

Preparation of Hazardous Materials for Military Aircraft

TM 55-1500-204-25/1

General Aircraft Maintenance Manual

TM 55-1500-342-23

Army Aviation Maintenance Engineering Manual: Weight and Balance

TM 55-1520-240-CL

Operators and Crewmembers Checklist

TM 55-1520-240-23

Aviation Unit and Aviation Intermediate Maintenance Manual

TM 55-1680-358-12&P

Operator and Aviation Unit Maintenance Instructions for Helicopters Internal

Cargo Handling System

TM 750-244-1-5

Procedures for the Destruction of Aircraft and Associated Equipment to Prevent

Enemy Use

Change 7 A-1/(A-2 blank)

TM 55-1520-240-10

APPENDIX B

GLOSSARY

Abbreviation

Term

Abbreviation

Term

AC .

Alternating Current

CHAN .

Channel

ACK .

Acknowledge

CHK .

Check

ACTR .

Actuator

CKPT .

Cockpit

ADF .

Automatic Direction Finding

CL .

Checklist

AFCS .

Advanced Flight Control System

Center Line

AGL .

Above Ground Level

CLR .

Clear

AIMS .

Air traffic control radar beacon system

CLR-VC .

Clear Voice

Identification friendly or foe Mark XII

CM .

Countermeasures

identification System

CMD .

Command

AJ .

Anti-Jam

CNV .

Crypto Net Variable

AK .

Automatic Keying

COMM .

Communication

ALP .

Alpha

COMP .

Compass

ALSE .

Aviation Life Support Equipment

COMPT .

Compartment

ALT .

Altitude

COND .

Condition

AM .

Amplitude Module

CONT or

AME .

Amplitude Modulation Equivalent

CONTR .

Control

AMP .

Ampere

COPLT or

ANT .

Antenna

CPLT .

Copilot

ACK .

Acknowledge

CPDU .

Copilot display unit

ANVIS .

Aviation Night/Vision Imaging System

CPM .

Control processor and communication

APU .

Auxiliary Power Unit

CRS .

Course

APPROX .

Approximately

CRT .

Cathode Ray Tube

AR .

Army Regulation

CTR .

Center

AS .

Airspeed

CW .

Continuous Wave

ASTM .

American Society for Testing Materials

DA .

Density Altitude

ATM .

Aircrew Training Manual

DASH .

Differential Airspeed Hold

AUTO .

Automatic

DAT .

Data

AUX .

Auxiliary

DC .

Direct Current

AVAIL .

Available

DCLT .

Declutter

AVGAS .

Aviation Gasoline

DCP .

Differential Collective Pitch

BARO .

Barometric

DEC .

Decrease

BATT or

DEST .

Destination

BTRY .

Battery

DET or

BCN .

Beacon

DETR .

Detector

BFO .

Beat-Frequency Oscillator

DF .

Direction Finder

BIT .

Built in Test

DIM .

Dimensions

BITE .

Built in Test Equipment

DIS .

Disable

BL .

Butt Line

DISCH .

Discharge

BRK .

Brake

DISP .

Display or Dispenser

BRT .

Bright

DIST .

Distance

BRG .

Bearing

DN .

Down

BTU .

British Thermal Unit

DOP .

Doppler

C .

Celsius

DSPL .

Display

CAS .

Calibrated Airspeed

DU .

Display unit

CCR .

Closed Circuit Refuel

E .

East

CCU .

Converter control unit

EAPS .

Engine Air Particle Separator

CDR’s .

Commander’s

ECM .

Electronic Countermeasure

CDU .

Computer display unit or control display

ECCM .

Electronic Counter Countermeasures

unit

EDT .

Edit

C.G. .

Center-of-Gravity

EMER or

CGI .

Cruise Guide Indicator

EMERG .

Emergency

ENG .

Engine

ENT .

Enter

Change 14 B-1

TM 55-1520-240-10

Abbreviation

Term

Abbreviation

Term

ERFS .

Extended Range Fuel System

HTR .

Heater

ERFS II .

Extended Range Fuel System II

HUD .

Heads up display

ETL .

Effective Translational Lift

HYD .

Hydraulic

EXH .

Exhaust

Hz .

Hertz

EXT .

Extend, Extinguisher, or External

I .

Inner

F .

Fahrenheit

IAS .

Indicated Airspeed

FARE .

Forward Area Refueling Equipment

ICS .

Intercommunication System

FAT .

Free Air Temperature

ID or

FCP .

Fuel Control Panel

IDENT .

Identification

FH .

Frequency Hopping

IFF .

Identify Friend or Foe

FIG .

Figure

IFR .

Instrument Flight Regulations

FIL .

Filament

IGE .

In Ground Effect

FL .

Flow

IGN .

Ignition

FLP .

Flight Plan

ILCA .

Integrated Lower Control Actuator

FLT .

Flight

ILS .

Instrument Landing System

FLT CONT .

Flight Control

IMC .

Instrument meteorological conditions

FM .

Frequency Modulated

IN. or ” .

Inch

FMCP .

Fuel Management Control Panel

INC. .

Increase

FM-M .

Frequency Hopping Master

IND .

Indicator

FMT .

Frequency Managed Training

INOP .

Inoperative

FOD .

Foreign Object Damage

INST .

Instruments

FPM or FT/

INT or

MIN .

Feet Per Minute

INPH .

Interphone

FREQ or

INTR .

Interior

FRQ .

Frequency

ITO .

Instrument Takeoff

FT .

Feet

JP-4, JP-5 or

FUSLG or

JP-8 .

Jet Petroleum

FUS .

Fuselage

K .

Key

FWD .

Forward

KYBD .

Keyboard

G .

Green

kHz .

Kilohertz

G’s .

Gravity

KIAS .

Knots Indicated Airspeed

GALS .

Gallons

Km .

Kilometer

GCA .

Ground Controlled Approach

KN or KTS .

Knots

GD XMIT .

Guard Transmitter

L .

Left

GEN .

Generator

LAT/LONG .

Latitude/Longitude

GMT .

Greenwich Mean Time

LB .

Pound(s)

GND .

Ground

LB-FT .

Pound-Feet (Torque)

GPM .

Gallons per Minute

LB/GAL .

Pounds Per Gallon

GS .

Glide Slope

LB/HR .

Pounds Per Hour

GS/TK .

Ground Speed/Track

LBL .

Left Butt Line

GW .

Gross Weight

LCT .

Longitudinal Cyclic Trim

GYRO(s) .

Gyroscope(s)

LD .

Load

H .

High

LD-V .

Load Variable

HDG .

Heading

LF .

Low Frequency

HF .

High Frequency

LG .

Length

Hg .

Mercury

LH .

Left-Hand

HGT .

Height

LO .

Low

HI .

High

LOC .

Location

HICHS .

Helicopter Internal Cargo Handling

LSB .

Lower Sideband

System

LTG .

Lighting

HIGE .

Hover In Ground Effect

LTS .

Lights

HIT .

Health Indicator Test

LVL .

Level

HOGE .

Hover Out of Ground Effect

M .

Mode or Middle

HR .

Hour

MA .

Missile Alert

HSI .

Horizontal Situation Indicator

MAG .

Magnetic

HTG .

Heating

MAL .

Malfunction

MAM .

Manual

B-2

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TECHNICAL MANUAL MAINTENANCE MANUAL FOR ARMY CH-47D HELICOPTER (1992) - page 12