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

TM 55-1520-240-10

4-2.

Controls and Function, Radar Signal

Detecting Set Indicator. (fig. 4-0)(Continued)

Threat Symbols

Threat symbols corre-

spond to threat signals

detected and identified

by system. A maximum

of seven threat symbols

(classified) can be dis-

played at the same time.

Unidentified threat sig-

nals are displayed as an

unknown (symbol U).

4-3.

Multi-Function Display and Control Display

Unit Controls and Function, Radar Signal

Detecting Set AN/APR-39A(V)1.

The radar signal detecting set is turned on via the EQUIP-

MENT STATUS PAGE 5 OF 5. It is accessed by pressing

MFD key T5 SYST until SYST* is displayed. Then press

MFD key L3 EQP STAT to access EQUIPMENT STATUS

PAGE 1 OF 5. Access to EQUIPMENT STATUS PAGE 5 OF

5 is accomplished by preorn

Press MFD

- SEQor L2 Øto place cursor by

RWR then press MFD key R2 PWR OFF to display PWR ON.

Access to the ASE control layer is accomplished by pressing

CDU dedicated key VCR/ASE. Page 1 of the ASE control

layer is displayed. Page 2 is accessed by pressing CDU dedi-

cated k- or

Ø.

Figure 4-2.

Radar Signal Detecting Set Control

4-4. Normal Operation - Radar Signal Detecting

Set. This paragraph provides radar signal detecting set

operating procedures.

4-2.2

Change

TM 55-1520-240-10

CAUTION

To prevent damage to the antenna detectors

(when operating) never operate the AN/APR-

39A(V)1 within 60 yards of ground based

radars or within six yards of airborne radar

antennas. Operating the system closer than

these limits may damage the antenna-

detectors. Allow an extra margin for new,

unusual, or high-powered radar transmit-

ters.

CAUTION

Excessive indicator display brightness may

damage the CRT. Set indicator BRIL control

for readable display.

a. Starting.

(1)

PWR switch -

ON. Allow 1 minute for war-

mup - Check for synthetic voice message

“APR-39 POWER UP”.

(2)

BRIL control -

adjust display of (+ ) sym-

bol.

Figure 4-3.

Radar Signal Detecting Set (OFP and

(3) MODE switch -

Select MODE 1 (up) for

normal messages. Select MODE 2 (down)

EID VERSION DISPLAY)

for terse (abbreviated) messages.

(d)

TEST switch

- Press. Performs a test on

b. Self-test check

the synthetic voice status messages. A no

fault detected during test will end with

(1) MODE switch - Set position 1 (up)

message “APR-39 OPERATIONAL”

any fault detected will end with message

NOTE

“APR-39 FAILURE”, which will be

SYSTEM SELF-TEST provides a six step

heard over the ICS.

test of system functions. A complete system

self-test is initiated any time the test button

(e)

TEST switch

- Press. Performs the plus

is pressed. The complete system self test

(+) symbol display status. The plus (+)

runs in less than thirty seconds. The following

symbol will be displayed, centered within

is a description of the system functions.

the small circle on the indicator, anytime

the system is operational.

(2) TEST - As follows:

MODE switch - MODE 2 (down), TEST

(f)

(a)

TEST switch

- Press. A synethic voice

switch

- Press. Performs the synthetic

long count is performed. The audio mes-

voice short count. Listen to synethic voice

sage “SELF-TEST, SET VOLUME 1, 2,

message and adjust volume. Mode 2 short

3, 4, 5, 6, 7, 8, 9, 10, 11, 12’’...will be heard

count is: “SELF-TEST SET VOLUME 5,

on the ICS.

4, 3, 2, l.”

(b)

TEST switch -

Press. A display of two

(3) The following fault display conditions are the

numbers which represent the installed

result of a bad self test, and will result in an

software revision on the indicator; one

audio message

“APR-39 FAILURE” over

number (OFP-Operational Flight Pro-

the ICS.

gram) at the top and one number (EID-

Emitter Identification Data) at the bot-

(a) If a receiver fault is noted, faulty receiver

tom (fig. 4-3). Check OFP and EID

is shown as two triangles, (fig. 4-4) repre-

numbers are correct for theater or mis-

senting right and left video channel(s)

sion.

will be flashing.

Press. Performs the Re-

ceiver and AN/AVR-2 status display. See

(b)

A faulty C/D band amplifier in a proces-

figure 4-4 for normal indicator displays,

sor is shown as a flashing square centered

and faulty indicator displays.

on indicator display (fig. 4-4).

Change

4-3

TM 55-1520-240-10

(c)

The Laser Detecting Set (LDS)(AN/

interval following each pulsed transmission. Built-in-

AVR-2) status is displayed along with the

test-equiptment monitors system operation. If a mal-

receiver status. A faulty LDS quadrant is

function is detected, the system is disabled and the CM

shown as a flashing asterisk. LDS faults

INOP caution capsule on the master caution panel will

do not cause an audio message “APR-39

come on. Also, if enemy jamming or interference from

FAILURE”, heard over the ICS.

other countermeasures sets is detected, the set will

automatically shift to a clear channel. The set receives

(d) If LDS is not installed, all four quadrants

AC electrical power from the No.2 AC bus through the

(asterisks) will flash.

MSL DET SYS circuit breaker on the No.2 PDP. The

(4) Operating In A Dense Signal Environment.

set receives DC power from the No.2 DC bus through

(a) When a dense signal environment is de-

the MSL DET SYS circuit breaker also on the No.2

tected, the plus (+ ) symbol on the Radar

PDP.

Signal Detecting Set (RSDS) indicator

will flash, and the voice message

4-6. Controls and Indicators, Missile Detector Set

“THREAT DETECTION DEGRAD-

(AN/ALQ-156). (fig. 4-6)

ED’’ will be announced over the ICS.

CONTROLS/

(b) Position mode switch to mode 2,(terse

INDICATOR

FUNCTION

mode). When the plus (+) symbol stops

flashing, the voice message “THREAT

POWER OFF/ON

At ON, power is applied

DETECTION RESTORED’’ will be an-

to set. The switch is

nounced over the ICS.

locked at ON. Signals ra-

diate after the normal

4-5. Countermeasures Set (AN/ALQ-156).

warmup period is com-

pleted.

The Countermeasures Set (AN/ALQ-156) detects the

STBY Indicator Light on

Lights when switch is de-

approach of anti-aircraft missiles, and signals the M-130

STATUS Switch

pressed and system is in

Flare Dispenser to launch flares to decoy the missiles

standby operation.

from the helicopter. The set consists of a control unit on

the console, a receiver-transmitter in the electronics

Amber Warmup Caution

Lights when power is ap-

compartment, two antennas on the bottom of the fuse-

Light on STATUS Switch

plied to set and remains

lage, and two caution light capsules on the master

on until operating temper-

caution panel. The set alternately applies pulsed signals

atures are reached.

to the two antennas which radiate the signals about the

FLARE TEST Switch

Simulates launch com-

helicopter. A missile approach is detected by the fre-

mand signal to flare dis-

quency shift of the transmitted signals echo returned

penser.

from the missile. Any echo is received during the

CM INOP Caution Light

When lit indicates the set

(on caution panel)

has failed and the heli-

copter is without counter-

measures protection.

CM JAM Caution Light

Lights when system de-

(on caution panel)

tects mutual interference

from nearby countermea-

sures sets or enemy jam-

ming.

Figure

4-5. (Deleted)

Change 1

4-4.1

TM 55-1520-240-10

NOTE

Although the control panel, dispenser, and

The system requires a 10-minute warmup

circuit breaker are marked CHAFF or have

prior to operation. To ensure automatic sys-

CHAFF (C) selector positions, chaff cannot

tem operation when required, be sure the set

be dispensed at this installation.

is operational and all caution and indicator

lights are out prior to entering hostile areas.

4-9. Dispenser Control Panel. The DISP CONT

panel is installed in the center console. The panel

(2) POWER control switch - ON.

contains the ARM SAFE switch, ARM indicator light,

(3) Warmup light -

ON, allow 10 minutes for

RIPPLE FIRE switch, FLARE counter, and counter

warmup. At the end of the warmup period,

setting knob. The panel also includes a MAN-PGRM

the warmup light will be shut off.

switch and CHAFF counter, which are not used in this

b. ECM operation.

installation.

(1)

STATUS switch -

Push for standby opera-

4-10. Dispenser Status Panel. The dispenser status

tion or release to commence automatic pro-

panel (fig. 4-7) provides an indication of safety relay

tection.

operation and system arming. It also allows the landing

(2)

CM JAM caution light - Check OUT.

gear safety switch to be bypassed for ground testing of

the dispenser system. The panel is on the left side of the

(3)

CM INOP caution light - Check OUT. If

cabin at sta 534.

caution light is on, the set has malfunctioned

and the helicopter is without countermea-

sures protection.

4-11. Controls and Function, Flare Dispenser Sys-

tem (M-130). (fig. 4-7)

(4) POWER switch -

OFF when countermeas-

ures protection is no longer required.

CONTROLS/

INDICATOR

FUNCTION

ARM/SAFE Switch

At SAFE, the system is

not powered. At ARM,

If the countermeasures set has been off for

the system is powered,

less than 5 minutes and further operation is

provided the safety pin is

required, the warmup indicator light may go

removed from the elec-

out immediately (or within some interval less

tronic module and the

than the normal 10 minute warmup period)

ground safety relay is en-

after the power switch is set to on. If this

ergized. (Helicopter air-

occurs, it is mandatory that the system be

borne or remote bypass

operated in STBY for at least 1 minute.

switch on remote test

Failure to observe this requirement can re-

panel is at BYPASS.)

sult in a false alarm (launch) and or trans-

mitting frequency instability resulting in in-

ARM Indicator Light

Red PRESS-TO-TEST

terference with other countermeasures sets.

warning light indicates,

when lit, that ARM/

SAFE switch is at ARM,

4-8. Flare Dispenser M-130.

safety relay is closed, and

The Flare Dispenser M-130 (fig. 4-7) will dispense up to

safety pin is not installed

30 decoy flares as a countermeasure to infrared-seeking

in electronic module.

missiles. The externally mounted dispenser is controlled

FLARE Counter

Two digit counter displays

by a DISP CONT control panel on the console and six

number of flares remain-

firing switches. Two cockpit firing switches are pro-

ing in the dispenser. The

vided, one on each pilot’s control stick grip. Four

number of flares loaded is

hand-held crewmember firing switches are installed in

set manually, using the

the cabin area. Flares can also be automatically fired by

knob directly below the

firing commands from the countermeasure set (AN

counter.

ALQ-156) if the set detects a missile approach. A timer

RIPPLE FIRE Switch

Guarded two-position

in the cabin provides a 2.5 second delay between firing

switch allows rapid emer-

pulses regardless of firing switch position. A ground

gency ejection of all re-

safety relay, controlled by a landing gear proximity

maining flares.

switch and a safety pin manually installed into the

dispenser, prevents firing flares when the helicopter is

CHAFF Counter

Not used in this installa-

on the ground. The system is powered by the No. 1 DC

tion.

bus through the CHAFF circuit breaker on the No. 1

PDP.

4-5

55-1520-240-10

1. Dispenser Assembly.

CONTROLS/

INDICATOR

FUNCTION

a. Selector switch - Set to F.

MAN/PGRM SwitchLight intensity controllb.

Safety pin - Remove and sto

by caution panel DIM/

c. Flares - Note quantity inst

BRT SW.

Dispenser Statu(fig. 4-7)

2. Dispenser Status Panel.

READY TO FIRE LAmber light comes on

a. LDG GR SW BYPASS switch -

when system is armed and

Cover down.

ready to fire. Light

b. Indicator lights - PRESS-TO

receives power through

timer and will go out 3.Cabin hand held firing switch

2.5 seconds after flare

and secured in holder.

launch.

4. Cockpit Control Panel.

LDG GR SW STATUS

Green light comes on

a. RIPPLE FIRE switch -Cover d

Light

when ground safety relay

is deactivated. The safety

b. ARM/SAFE switch-SAFE.

relay is deactivated when

the helicopter is airborc.

FLARE counter - Set to amo

or bypassed via the LDG

dispenser.

GR SW BYPASS switch.

4-14. In-Flight Operation.

LDG GR SW BYPASRed light, when lit, indi-

1. After liftoff, LDG GR SW STAT

Light

cates that the ground

on remote test panel - Check

safety relay is bypassed

(NORMAL/BYPASS

2.ARM/SAFE switch - ARM. Check

switch is at BYPASS).

light lit.

NORMAL/BYPASS

Guarded switch. At

3. READY-TO-FIRE light on disp

Switch

BYPASS, the landing

- Check lit.

gear safety switch is

bypassed. Switch nor-

4.ECM set - ON. Allow 10 minute

mally used to test systeECM set will monitor the area

prior to installing flarter

for missiles and automati

missiles are detected.

Cyclic Stick FLPushbutton switch on side

Switch

of each cyclic stick. Fires

NOTE

a flare each time when

The flare dispenser can be safe

pressed.

the cabin through the filtered g

Hand Held FirinLocated in forward and

left side of the helicopter abo

Switches (4)

aft cabin sections. Wh575.

pressed, a single flare is

5.If the ECM set is inoperative

fired.

NOTE

4-12. Normal Operation

- M-130 Flare Dispenser.

The crewmember observing a miss

4-13. Preflight.

responsible for firing the flar

WARNING

(a) Missile threat

- Actua

An inadvertent flare launch can occur when

switch on the cyclic gri

the Flare Dispenser System is armed (control

chaff or press one of the

switch at ARM) and the Countermeasures Set

in the cabin to tire fla

is operating (CM caution and indicating lights

three flares or hold butt

will automatically space

off).

Change

4-7

55-1520-240-10

NOTE

be readjusted. The system self test is

The flare dispensers will fire oner-up or operator initialized built-in

time a button is pr2.5 se-

flight BIT. The system built-in-test (

during power-up or selected by the ope

cond time d2.5 second intervals if

BIT is a periodic test that is perfor

the flare dispense button is held down. If the

along with normal system operation. A

flare fails to ignite. a second flare will auto-

SDC. pilots DU. or copilots DU will

matically f

milliseconds. If

CCU FAIL light and display a FAIL messag

burning is still not detected. a tWhen a fail mes

sage is displayed on th

be fired. If all three flares failtor should acknowledge the failure an

matic operation will stop until onconfirm the fault. 26-volt AC to opera

switches is again pressed.

tem is taken from the No.1 INSTXFMR t

NOTE

HUD REF circuit breaker on the No.1 PD

he system is taken from the ESS

Firing chaff in MAN (manual) modforit

through the HUD SYS circuit breaker als

dispense chaff one pair at a time or according

PDP

to the setting of

hen set in

the PROG (programmed) mode.

4-16.2 Controls and Function, Converter Control Unit.

(b) Announce over interphone tha(fig.4-7.1)issile launch was

detected and flares have been fired.

CONTROLS/

INDICATOR

FUNCTION

firing flares at 3-second intervals until the helicopter is

clear of the threat.

CPLT

4-15. Before Landing Check.

BRT/DIM Switch

Three position toggle

1. ARM-SAFE switch-Set to SAFE.

switch spring loaded to

2.Indicator lights - Check that READY- TO -FIRE and

off. When placed to

ARM lights are out.

BRT or DIM position

momentarily, copilots

4-16. After Landing Check

display will increase or

1.Check that the LDG GR SW STATUS light goes out.

decrease brightness

2.Install the ground safety pin in the dispenser el(when held. display will

go full bright or full

ic module.

dim).

3.Remove and stow the crew firing switches.

4-16.1 Heads Up Display (AN/AVS-7) System

DSPL POS D/U/Copilots control for dis

The Heads U Display (HUD) System (fig.

4-7.1)

play position down/u

serves as an aid to pilots using the AN/AVS-6 (ANV(outer knob) and left/

during night flight operations. The system allowright

(inner knob).

pilot and copilot to receive flight data without viewing

MODE

1-4/DCLT

Three position toggle

the instrument panel. Instrument data is applied to the

switch spring loaded to

system, processed far display, and superimposed over

off. Changes the copilo

the ANVIS image. The set consists of the Converter

primary mode and/or

Control Unit (CCU) on the console. The Signal Data

ry mode’s declutter

Converter (SDC) on the avionics shelf. an inclinoprima

display.

and air data transducer both located on the avionics

shelf. a HUD control switch on the pilots/copilots

PLT

THRUST CONT (control) lever, and the Display Unit

(DU). consisting of the Optical UniBRT/DIM SwitcThree position toggle

Supply Calibration Unit (PSCU). The CCU selects pswitch spring loaded to

lot/copilot programming which allows the pilot anoff.

When placed to

pilot to select information far their respectiveBRT oray

DIM position

modes from a master set ofc

opi-

momentarily. copilots

lot can independently program up to eight disp display will increase o

modes. four normal and four declutter. which can bdecrease brightness

lected for display. Declutter can be used when les(when-

held. display wil

boling is needed. The declutter mode has four vgo full bright or full

symbols that will always be displayed: Airspeed.dim).

tude (MSL), Altitude (pitch and roll). and Engine

Torque(s). An adjust mode, during opDSPL POS D/U/Pilots control for disp

adjust barometric altitude, pitch and roll. If tposition down/up (outer

system loses operating power after adjustments hknob) and left/right (i

been made. the barometric altitude. pitch and rolneruknob).

4-8 Change

TM 55-1520-240-10

CONTROLS/

INDICATOR

FUNCTION

INDICATOR

FUNCTION

MODE 14/DCLT

Three position toggle switch

ALT/P/R DEC/INC

Three position toggle switch

Switch

spring-loaded to off. Changes

Switch

spring-loaded to off.

Active

the pilot’s primary mode and/or

when adjust mode is selected to

primary mode’s decluttered

decrease/increase altitude /pitch

display. Refer to paragraph 4-

/roll.

When adjusting altitude

16.11 for detailed procedures.

(MSL) momentary movement of

DEC/ INC switch will change

ADJ/ON/OFF Switch

Three position switch. Selects

data in 5 ft increments.

When

adjust mode, enabling the

DEC/INC switch is held for one

INC/DEC switch to adjust

second, data will change in 10 ft

altitude, pitch or roll.

Turns

increments.

Pitch and roll

power on/off to HUD system.

change in increments of

degree.

FAIL Light

Illuminates to indicate a system

failure.

PGM NXT/SEL

Three position toggle

switch

spring-loaded to off.

Active

ON Light

Illuminates to indicate when

when

program

mode

system is powered up.

selected.

Operator

can

preprogram four normal modes

P-PGM/OP/CP-PGM

Three position switch. Se-

and four declutter modes.

Switch

lects pilot program mode,

Operator

selects

flashing

operational mode or copilot

symbol for display or goes to

program mode. Used with the

next symbol. Once complete,

PGM NXT/SEL switch.

operator toggles ACK switch to

save programmed display. To

BIT/ACK Switch

Three position toggle switch

program full display, use ACK

spring-loaded to off. Placed to

after changing to new mode.

BIT momentarily, selects built-

in-test. Placed to BIT position

and held, changes display to

4-16.3.

Controls and Function, Pilot/Copilot HUD

symbol generator test mode

Control (THRUST CONT Lever). (fig. 4-7.1)

until switch is released. When

placed to ACK, used to

CONTROLS/

acknowledge displayed fault,

INDICATOR

FUNCTION

completion of adjustment. or

completion of programming

BRT/DIM

Allows pilot/copilot to control

sequence. After ACK is used to

brightness of their respective

acknowledge a fault, fault will

displays.

not reappear until BIT is

selected or power is cycled off

MODE/DCLT

Allows pilot/copilot to select

and on.

respective display modes or

declutter modes.

4-8.2 Change 7

TM 55-1520-240-10

4-16.4.

Controls and Function, Display Unit.(fig.

b. Copilot programming - switch set to CP-PGM.

4-7.1)

c. Operation (flight mode) - switch set to OP.

CONTROLS/

(Adjust - ADJ/ON/OFF switch to ADJ).

INDICATOR

FUNCTION

4-16.6.

Display Modes.

EYE SELECT

Selects the proper orientation of

the symbology for left or right

Symbology display modes are programmable by the pilot

eye viewing.

and copilot via the converter control unit located on the

console. Modes are defined by selecting from a master

symbology menu (fig.

4-7.2 and 4-7.3). Up to eight (8)

display modes, four normal and four declutter can be

4-16.5.

Modes of Operation.

programmed for each user and can be selected for

display using the display mode selection switch on the

There are two programming modes and one operational

pilot or copilot thrust control lever or on the CCU. The

mode for the HUD system selected by the programming

default declutter mode has a minimum symbology

switch on the CCU. The adjust mode is a sub-mode

display of:

under the operational mode.

Airspeed - No. 25

Pilot programming - switch set to P-PGM

Altitude (MSL) - No. 7

Attitude (pitch and roll) - Nos.

6, 20, 26

Engine Torque(s) - No. 22, 23

Figure 4-7.2. CH-47D HUD Master Mode Display

Change 7 4-8.3

TM 55-1520-240-10

No.

Symbol

Source

Range/Description

Angle of Pitch Scale

HUD System

+ 30° (100 units, tic marks flash when angle of pitch is

>+ 30°)

Bearing to Waypoint -

Doppler

0 - 359° (cursor will invert "V" when aircraft is moving

Pointer

away from waypoint)

Compass Reference

HUD System

0 - 3590 (100 units)

Scale

Aircraft Heading Fix

HUD System

Fixed Reference Mark

Index

Angle of Roll - Pointer

Vertical Gyro, Copilot

+ 300 (right turn moves pointer to right, pointer flashes

> ±300)

Angle of Roll - Scale

HUD System

+ 300 (100 units)

Barometric Altitude

Air Data Transducer

-1500 to 20,000 feet (set during adjustment mode)

(MSL)

Adjust/Program Mode

HUD System

ADJ or PROG

Message

OK/Fail

HUD System

OK or FAIL

Velocity Vector

Doppler

0 - 15 knots/15 kilometers, O - 3590

Rate of Climb Pointer

Air Data Transducer

±2000 feet-per-minute (used with vertical speed scale,

No. 15)

Radar Altitude (AGL) -

Radar Altimeter, Pilot

0 - 1000 feet (O - 200 feet, 1 foot units; 200 - 1000 feet,

Numeric

10 feet units; disappears above 999 feet, and reappears

below 950 feet)

Minimum Altitude

Radar Altimeter, Pilot

Blinking square around symbol - No.

12, set on pilot's

radar altimeter (use low set index)

Warning

Radar Altitude (AGL)

Radar Altimeter, Pilot

0 - 200 feet (disappears at 250 feet, reappears at 225

Analog Bar

feet; digital readout symbol, No.

12)

AGL, Vertical Speed -

HUD System

0 - 200 feet/ ± 2000 feet-per-minute

Scale

HUD Fail Message

HUD System

CPM, SDR, SDA, PS, PDU, CPDU, NAV, PGM; can be

cleared from the display by selecting "ACK" (See

NOTE)

Trim (Slide Ball)

Inclinometer

± 2 balls (left/right)

MST, MEM, HOOK

Master Caution Panel

MST, MEM, HOOK; cannot be cleared from the display

Messages

by selecting "ACK"

NOTE: After ACK is used to acknowledge a fault, the fault will not reappear until BIT is selected or power is

cycled off and on.

Figure 4-7.3. CH-47D HUD Master Mode Symbology Display (Sheet 1 of 2)

4-8.4 Change 7

TM 55-1520-240-10

No.

Symbol

Source

Range/Description

Sensor, Fire Warnings

Light Plate Ass’y,

ATn (failure of copilot VGI), MSL, IAS, FIRE; ATT,

Cockpit

MSL, and IAS can be cleared from the display by se-

lecting "ACK" (See NOTE). FIRE cannot be cleared.

Horizon Line (pitch

Vertical Gyro, Copilot

Pitch: ± 30° Roll: 0 - 359°

roll)

Display Mode Number

HUD System

IN - 4N for normal modes, ID - 4D for declutter

modes

Torque Limits

Torque Transducer

(> 100%, solid box) (> 123%, Thresholds, solid box

flashes)

Torque - Numerics

Torque Transducer

0 - 130% (flashes when engine torque separation is

greater than 5% threshold) Max % torque split between

cockpit panel and HUD is 3%

Ground Speed

Doppler

0 - 999 knots/ O - 530 km/h (dependent on doppler)

Indicated Airspeed

Air Data Transducer

0 - 220 knots (no symbol 00 knots and below, reappears

at 02 knots)

Attitude Reference

HUD System

Represents helicopter Indicator

Engines Temperature

Thermocouple

0 - 9990C (O - 755 C, 20 units; 7760C - 9990C, 1°

Amplifiers

units) Max split between cockpit and HUD is ±15

Distance to Waypoint

Doppler

0 - 999.9 km

Bearing to Waypoint -

Doppler

0 - 3590

Numeric

NOTE: After ACK is used to acknowledge a fault, the fault will not reappear until BIT is selected or power is cycled off and

on.

Figure 4-7.3. CH-47D HUD Master Mode Symbology Display (Sheet 2 of 2)

416.7.

Operation.

WARNING

416.8.

Starting Procedure.

Failure to remove the ANVIS neck cord

ADJ/ON/OFF switch - OFF.

prior to operation of the HUD may

prevent egress from the aircraft in an

Optical unit support clamps - Installed on ANVIS.

emergency and may result in serious

Verify clamps can be rotated.

injury or death.

NOTE

ANVIS neck cord - Removed.

Check surface of lens for cleanliness.

Optical unit Install on ANVIS. Attach Optical Unit

Clean in accordance with TM 11-5855-

(OU) to either ANVIS monocular housing. Do not tighten

300-10.

OU clamp completely with thumbscrew at this time. The

OU (display) may have to be rotated to horizon after the

DU lens - Check.

system is operating.

Change 7 4-85

TM 55-1520-240-10

NOTE

The helmet may now have to be

Allow

1 minute for display warmup.

rebalanced.

Display intensity is preset to low each

time ADJ/ON/ OFF switch is set from

EYE SELECT switch on PSCU - L or R.

OFF to ON.

WARNING

If a fault is displayed in the DU.

acknowledge fault and re-run BIT to

CCU ADJ/ON/OFF switch must be

confirm fault. If the fault remains notify

OFF before connecting or

AVUM personnel.

disconnecting

quick

release

11. BRT/DIM switch - As desired.

connector.

12. DSPL POS control As required. Center

CAUTION

display in field of view.

The AN/AVS-7 system should not

13.

Display aligned to horizon Check. Tighten

be used if the quick-release

OU clamp.

connector is not in working order.

4-16.9.

Operator Self Test (BIT).

PSCU Connect. Connect PSCU to

quickrelease connector by rotating the

BIT/ACK switch Press to BIT and hold. The

connector engagement ring.

ON and FAIL LIGHT will illuminate. At end

of BIT, FAIL indicator will extinguish (lamp

CAUTION

will not be visible when center console lights

are off).

Keep the protective caps on the

ANVIS whenever it is not in use.

Display Unit(s) Verify symbol generator test

Operate the ANVIS only under

mode software for CH-47 (figure 4-7.4).

darkened conditions.

BIT/ACK switch - Release.

NOTE

4-16.10.

Displayed System Faults.

Ensure ANVIS operator procedures have been

completed.

The system self test is divided into power-up or operator

initialized built-in-test (BIT) and in-flight BIT. The faults

P-PGM/OP/CP-PGM switch - OP.

result as warnings and messages that blink at a rate of

two per second in the Display Units.

NOTE

Part of the BIT is a periodic test that is performed

The system ON and FAIL lights will not be visible if the

automatically along with normal system operation. This

center console lights are turned off.

BIT monitors and/or tests SDC functions and/or signals.

A failure of the SDC. NAV signals, pilot’s DU, or copilot’s

ADJ/ON/OFF switch - ON. SYS ON and

DU will illuminate the converter control FAIL light and

FAIL lights illuminate and BIT will initiate

display a FAIL message CPM. SDR, SDA. PS NAV,

automatically.

PDU or CPDU on the Display Unit. An ATT (gyro

invalid), IAS (indicated air speed out of range), or MSL

10. FAIL light - Check. Light should go out after

(MSL altitude out of range) sensor failure warning

ten seconds. BIT is complete.

message will be displayed when condition exists. ATT,

IAS, MSL, NAV, PDU, CPDU. And all SDC faults can be

cleared by setting BIT/ACK switch to ACK.

4-8.6 Change 7

TM 55-1520-240-10

Figure 4-7.4. Symbol Generator Test Mode

The following helicopter status messages are also

Setting BIT/ACK switch to ACK will not clear MST, MEM,

displayed.

HOOK status messages, or FIRE warning

from the DU.

The caption MST (first priority) indicates

operation of the master caution warning

4-16.11. Programming Procedure.

lamp. This message will disappear during

the reset of the main warning lamp

NOTE

operation.

The programming procedure for the pilot

The caption MEM (second priority) indicates

and copilot is identical except for the

that the doppler data is not updated. A

location of controls on the CCU.

previous computed data is available. This

message will appear simultaneously with the

Select mode to be programmed (IN through

MEM lamp on the doppler operating panel.

4N). The first mode that will appear is "IN"

(Normal Mode 1).

The caption HOOK (third priority) indicates

the selected cargo hook has been opened in

P-PGM/CP-PGM/OPR switch - P-PGM or

the helicopter. The message will appear

CP-PGM.

after the reset of the master caution warning

light when any of the cargo hooks have been

opened.

Change 7 4-8.7

TM 55-1520-240-10

"PROG" blinking in display Check. Verify

NOTE

that a complete set of symbology is displayed and

attitude reference symbol is blinking. Verify "PGM" is

If MODE 14/DCLT switch is toggled to

displayed in the HUD FAIL message location for the DU

DCLT a second time the display will

not being programmed.

cycle back to the DCLT’s normal mode

(1N-4N). The MODE 1-4/DCLT switch

BIT/ACK switch ACK to program the full

must be set to MODE 14 to advance to

display or go to step 5 and select desired

another normal mode.

symbols.

Repeat steps 4 through 7. for declutter.

PGM SEL/NXT control SEL to select symbol.

Selected symbol stops blinking. If symbol is

10. Mode 1-4/DCLT switch - As required.

not desired, toggle switch to NXT and the

symbol will disappear.

11.

Repeat steps 4 through 10 until all desired

modes are programmed.

NOTE

12. P-PGM/CP-PGM/OP switch - OP.

All symbols have been programmed when

the "PROG" annunciator is the only symbol

WARNING

flashing.

An improperly adjusted barometric

BIT/ACK switch - ACK. (Hold switch to ACK

altimeter will result in an improperly set

for one second.)

HUD barometric altitude display.

NOTE

"OK" displayed

- Check.

("OK" will be

displayed for two seconds.)

Barometric altimeter set to the most current

altimeter settings, field elevation.

NOTE

4-16.12.

Adjustment of Barometric Altitude, Pitch,

If programming is not accepted, "FAIL" will be

and Roll.

displayed. If a fail message is displayed,

attempt to reprogram the same mode, if fail

Ensure P-PGM/OP/CP-PGM switch is in the

reappears notify maintenance.

OP position.

Declutter mode is recognized by flashing

ADJ/ON/OFF switch - Pull and set to ADJ.

ground speed indicator in lieu of attitude

reference symbology.

NOTE

MODE 1-4/DCLT switch - DCLT (ID through

Changes to barometric altimeter settings

4D). The first DCLT mode that will appear is

will require a corresponding change to

"ID" (Declutter Mode 1).

the HUD barometric altitude. Each 0.01

inch change in pressure equals 10 feet.

ADJ blinking in display - Check.

INC/DEC switch - as required.

BIT/ACK switch - ACK.

4-8.8 Change 7

TM 55-1520-240-10

Repeat steps 3 through 5 for pitch and roll.

4-16.14.

System Shutdown Procedure.

ADJ/ON/OFF switch - ON.

Set ADJ/ON/OFF switch - OFF.

116.13.

In-flight Operation.

Turn off ANVIS.

WARNING

Whenever the symbology displayed

in the DU is suspected of being

CCU ADJ/ON/OFF switch must be OFF

incorrect the pilot will compare the

before connecting or disconnecting

data with the aircraft instrument

quick-release connector.

indicator and take the appropriate

action.

WARNING

Do not disconnect DU by pulling on the

WARNING

cable connected to the PSCU. The DU

could be damaged or the cable may

Excessive

brightness

the

separate from the PSCU creating an

symbology display may impair vision

explosive atmosphere hazard.

outside the cockpit.

WARNING

Do not attempt to egress the aircraft

Interruption of electrical power, such

without performing disconnect as this

as change over from APU generator to

may result in neck injury.

NO. 1 and NO. 2 generators and vice

versa, will cause the DU to default to

CAUTION

minimum brightness and normal

MODE IN. Any adjustments made to

Do not disconnect DU by pulling on the

the barometric altitude, pitch and roll

cable. To do so may damage the DU.

prior to flight will be lost, thereby

decreasing the accuracy of the

Display Unit - Disconnect. Disconnect DU

by grasping the PSCU and rotating the

barometric altitude, pitch and roll.

quick-release connector engagement ring

and pull downward.

Remove OU by

BRT/DIM switch - As desired.

loosening thumb-screw on OU and remove

OU from the ANVIS and place into protective

NOTE

storage case.

Whenever the symbology is interfering

Reattach neck cord to ANVIS.

with the outside visibility. declutter may

be selected to remove symbology.

MODE 1-4/DCLT switch - As required.

Change 7 4-8.9

TM 55-1520-240-10

SECTION II

ARMAMENT

4-17. Armament Subsystems.

a. Maximum traverse (table 4-1) of the machine gun

are controlled by stops on both sides of the cam on the

The armament subsystems, (fig. 4-8) are the M24, and

pintle post.

M41 machine guns installed in the cabin door, cabin

escape hatch, (M24) and on the ramp (M41). The two

b. Maximum elevation and depression are controlled

flexible 7.62 mm machine guns (M60D) (fig. 4-9) are

by cam surfaces on the pintle.

free pointing but limited in traverse, elevation, and

c. The quick-release pin (fig. 4-12) is attached by

depression by cam surfaces, stops on the pintles, and

cable to the mount bracket of the mount and fastens the

pintle posts of the left and right mount assemblies (fig.

mount bracket to the rear bracket at the helicopter

4-10). Spent cartridges are collected by an ejection

opening.

control bag on the right side of the machine gun, and an

ammunition can is on the left side (fig 4-11).

d. The shock cord (fig. 4-13) is fastened to the mount

bracket and to the machine gun when stowed.

4-18. Machine Gun.

4-22. Operation - Armament Subsystem M24.

The 7.62 machine gun (M60D) is a link-belt-fed gas-

operated air-cooled automatic weapon. Refer to TM

Operate the ARMAMENT SUBSYSTEM M24 as de-

9-1005-224-10

scribed in the following paragraphs.

4-19. Mount Assemblies (M24).

4-23. Preflight Checks. The preflight check consists

of the following:

The mount assemblies (fig. 4-12) are installed on mount-

ing brackets fastened inside the helicopter and secured

Machine Gun M60D

- Check to make sure

with mounting pins.

that gun is thoroughly cleaned and lubricated,

operable, and secured on the pintle with the

4-20. Machine Gun Controls.

quick-release pin (fig. 4-16).

For information on the operation and maintenance of

Ejection control bag (fig. 4-14) - Installed

the M24 and M41 machine gun systems, refer to TM

and securely latched.

9-1005-224-10 and 9-1005-262-13.

Ammunition can (fig. 4-15) - Installed on ma-

chine gun and loaded.

Safety

- Push button to safe (S) position, aim

To prevent injury to personnel, the cocking

at clear area, and try to fire the unloaded

handle must be returned to the forward or

machine gun.

locked position before firing.

Mount

- Secured and checked for free pintle

movement.

6. Extra ammunition boxes -

Properly stowed.

4-24. Before Takeoff Check.

Pressing the trigger to release the bolt ac-

1. Check the weapon safety is on - (S) position.

complishes feeding and releasing of the fir-

ing mechanism. Unless firing is intended,

2. Inspect the chamber to be sure it is clear.

make sure the machine gun is cleared of

Table 4-1. Armament Subsystem M24 Data

cartridges before pressing the trigger.

Effective range

1100 meters (max)

Rate of fire

550-650 rnds per min.

Length, overall

44.875 in.

To prevent damage to the cartridge tray

Sighting

Aircraft ring and post type

when no ammunition is in the machine gun,

retard the forward force of the released bolt

Total traversing capability - left side

122°

by manually restraining forward movement

Total traversing capability - right side

127°

of the cocking handle.

Depression and elevation limits:

Left side maximum depression

67°30’

Left side maximum elevation

7°30’

4-21. Mount Assembly Stops, Cams, Quick-

Release Pin, and Shock Cord (M24).

Right side maximum depression

73°

Right side maximum elevation

7°

The mount stops, cams, quick-release pin, and shock

cord have the following functions:

4-9

TM 55-1520-240-10

2. Firing.

b. Retract the bolt by pulling the handle fully

rearward until the sear engages and then

With the machine gun loaded and aimed, push the

push the handle to forward position. Move

safety button to fire (F) position. Because of the low

the cover latch rearward to the horizontal

rate of fire, single cartridges or short bursts can be fired.

position and then raise the cover. Remove

The trigger must be completely released for each shot to

the linked cartridges.

fire single cartridges or to interrupt firing. When the

ammunition is exhausted, the last link will remain in the

c. Inspect the chamber to be sure it is clear,

cartridge tray. Remove the link and the end plug by

d. Close the cover and secure the machine gun

hand after the cover is opened for loading.

in stowed position.

4-26. Ammunition.

The M60D machine gun is used for both the M24 and

Do not fire the M24 machine guns unless the

M41 armament subsystems. The ammunition for 7.62

ejection control bags are installed. Failure to

mm machine gun M60D is classified as small arms

install the bags before firing the machine

ammunition and is issued in linked belts. Issue is in

guns could cause the brass and links to be

proportion by types to meet tactical requirements (table

ejected overboard and ingested into the en-

4-2).

gines if engine screens are removed.

Table 4-2. Authorized Cartridges

7.62-millimeter: AP, NATO M61

7,62-millimeter: Ball, NATO M59

7.62-millimeter: Ball, NATO M80

The M24 machine guns are not to be fired

7,62-millimeter: Tracer, NATO M62

unless RRPM is at minimum beep or higher.

7,62-millimeter: Dummy, NATO M63

3. After Firing Operation.

a. Push the safety button to safe (S) position,

4-27. ARMAMENT SUBSYSTEM M41.

aim at safe area, and try to fire the machine

Armament subsystem M41 is installed at the rear edge

gun.

of the ramp. The mount has a pintle and post with

Figure 4-16. Machine Gun Positioned on Pintle - Left Side Shown

4-16

TM 55-1520-240-10

limiting cam surfaces similar to those on armament

4-28. Mount Assembly (M41).

subsystem M24 mount assembly. The machine gun,

The mount is positioned on the lugs of the ramp bracket

ammunition can, and ejection control bag are the same

and is secured with a quick-release pin (fig. 4-17).

as those on armament subsystem M24.

NOTE

If the bracket must be installed, be

sure to

center it along the rear edge of the loading

ramp.

4-29. Mount Assembly Stops, Cams, Quick-

Release Pin, and Elastic Cord (M41). The mount

stops, cams, quick-release pin, and elastic cord have the

following functions:

a. Maximum traverse, elevation, and depression of

the machine gun M60D are controlled by cam surfaces

and stops on the pintle and the pintle post (table 4-3).

b. The quick-release pin, attached by cable to the rear

of the mount, secures the mount to the ramp (fig. 4-17).

c. The elastic cord is fastened to the mount and the

machine gun when holding it in a stowed position.

Table 4-3. Armament Subsystem M41 Data

Effectivc range

1100 meters (max)

Rate of fire

550-650 rnds per min.

Length, overall

44.875 in.

Sighting

Aircraft ring and post type

Total traversing capability

94°

Elevation

12°30’

Depression

69°

4-30. Operation - Armament Subsystem M41.

Operation of the armament subsystem M41 is the same

Figure 4-17. M41 Mount - Installed on Ramp

as operation of the M24.

4-17

TM 55-1520-240-10

SECTION Ill CARGO HANDLING SYSTEMS

4-31. Winch/Hoist System.

NOTE

The cable cutter arming device must be

A 3,000-pound-capacity hydraulically operated winch

plugged into the receptacle on the auxiliary

(fig. 4-18) is mounted on the floor in the right forward

control panel at sta 95 (fig. 4-21) and the

cabin at sta 120. Hydraulic power cooperate the winch

cable speed selector lever must be at

is supplied by the utility hydraulic system. The winch

CARGO to complete the winch control cir-

(fig. 4-19) has

150 feet of usable ¼ inch cable. It is

cuit for cargo operations. The cable cutter

capable of winching up to

12,000 pounds of cargo with

arming device must be plugged into the

the aid of pulley blocks. When used in hoisting mode

receptacle on the overhead above the utility

(fig. 4-26), the load is limited to

600 pounds. The winch

hatch (fig. 4-23) and the cable speed selector

has two maximum reeling speeds: one for cargo loading

lever must be at RESCUE to complete the

(20 fpm) and one for hoisting

(100 fpm).

When the

hoist control circuit for hoisting operations.

winch is used for cargo loading, a selector control lever

on the cable drum housing is moved to CARGO. When

a. Winch control switches (overhead switch panel).

the winch is used for hoisting, the selector control lever

is moved to RESCUE. A mechanical braking device

(1)

Hoist master switch. A toggle hoist master

automatically locks the cable drum when power is off,

switch is on the hoist control panel (fig. 4-20).

preventing loss of load control through cable payout. If

The switch (labeled HOIST MSTR) has po-

sitions marked REMOTE, OFF, and PLT.

the winch cable load exceeds

3,200 pounds,

an overload

When the switch is at REMOTE, electrical

switch will automatically stop the winch. The free end of

power from the 28-volt No. 1 DC bus, through

the winch cable is equipped with a metal ball which

the HOIST CONT circuit breaker, energizes

locks into one end of a quick-disconnect device that is

the winch arming switch on the winch/hoist

used to attach hooks to the cable. Both ends of the cable

control grip. Once this switch is pressed, the

are painted red for

20 feet to alert the operator that the

winch cable switch, also on the grip, is ener-

cable end is approaching. In CARGO mode, the winch

gized, allowing the winch reeling speed to be

will automatically stop when the cable is reeled out

150

controlled at the hoist operator’s station.

feet, and at 3 feet when the cable is reeled in. In

When the master switch is at PLT, electrical

RESCUE mode, the winch will stop when the cable is

power energizes the hoist control switch on

reeled out

150 feet and at 28.5 feet when the cable is

the overhead switch panel, which gives the

reeled in.

pilot control of the hoisting system. When the

switch is at OFF, power is removed from the

4-32. Winch Controls.

hoist control switches at both stations.

The winch can be controlled from the cockpit by

(2)

Hoist control switch. A spring-loaded,

switches on the overhead switch panel (fig. 4-20) or

rheostat-type switch is provided for hoist

from the cargo compartment by switches on the winch/

control and is on the hoist control panel. The

switch (labeled HOIST) has positions marked

hoist control grip. The switches in the cockpit override

the switches on the control grip, enabling the pilot to

OFF, IN, and OUT. When the hoist master

switch is at PLT, electrical power, from the

assume control of hoisting operations in an emergency,

28-volt No. 1 DC bus through the HOIST

When operating from the cargo compartment, the winch-

CONT circuit breaker, energizes the hoist

hoist control grip can be plugged into a receptacle on

control switch. Then the switch is moved to

the auxiliary control panel (fig. 4-21) at sta 95, the hoist

IN or OUT, the hoist brake release solenoid

operators panel at sta 320 (fig. 4-25), or the receptacle

valve is energized open. The open valve ap-

at sta 502 (fig. 4-22) by an extension cord. The winch can

plies hydraulic pressure through the hoist

also be manually operated from the cabin. These con-

control valve to the winch to turn the cable

trols are for emergency use only. The controls are

drum in the appropriate direction. The speed

mounted on the structure in the heater compartment.

of the cable is proportional to hoist control

Instructions for manual operation of the winch are on

switch movement. When the switch is re-

the structure above the control valves and instructions

leased, the switch assumes the center OFF

in this section. Electrical power to operate and control

position. In addition, the brake release sole-

the winch is supplied by the 28-volt No. 1 DC bus

noid valve is deenergized closed, which re-

through two circuit breakers on the No. 1 PDP. These

moves hydraulic pressure to brake the cable

two circuit breakers are marked HOIST CABLE CUT-

drum.

TER and HOIST CONT.

(3) Cable cutter switch. A cable cutter switch is

on the left side of the hoist control panel. The

guarded switch (labeled CABLE CUT) has

4-18

TM 55-1520-240-10

(1) Winch arming switch. The winch is armed for

use by a trigger-type, spring-loaded switch.

When the swtich is pressed, a circuit closes,

arming the control circuits of the winch hy-

draulic motor. When the switch is released,

the circuit opens, rendering the winch inop-

erable.

NOTE

The winch arming switch must be pressed to

operate the winch.

(2)

Winch cable switch. Winch cable reeling is

controlled by a rotary switch on the left side

of the control grip. Action markings around

the switch are IN, OFF, and OUT. The

switch is spring-loaded to center OFF posi-

tion. When the switch is moved to IN or

OUT, a selector valve in the winch hydraulic

system is electrically actuated, providing hy-

draulic pressure to turn the cable drum. The

speed of the cable is proportional to cable

switch movement in either direction.

(3)

Cable cutter switch. A pushbutton switch on

Figure 4-24. Winch/Hoist Control Grip

the upper shoulder of the control grip actu-

ates the cable cutter. A metal guard marked

CABLE CUTTER prevents accidental clos-

ing of the switch. When pressed, the switch

closes a circuit, providing electrical current to

fire a ballistic cartridge in the cable cutter.

The firing propels a cutter which cuts the

cable.

(4)

A cargo hook release switch.

(5) Microphone switch.

When using the microphone switch on the

hoist control grip, be careful not to press the

cargo hook switch.

4-33. Winch Operation.

With hydraulic and electrical power available, the winch

can be operated from the cockpit or from the cargo

compartment, in either the cargo mode (for winching

cargo into the cargo compartment via the ramp) or in

the rescue mode (for rescue or hoisting small cargo

through the rescue hatch).

a. Control settings and electrical connections for op-

erating the winch in the

cargo mode from the

Figure 4-25. Hoist operators Panel (Station 320)

cockpit are as follows:

(1)

Cable speed selector lever on the winch -

used in hoisting, winching, and cargo hook opera-

CARGO.

tions. A receptacle for plugging in the extension

cord cord is in the butt end of the grip. A hook

(2)

Cable cutter arming device (or adapter cable,

extending from the side of the grip is used to hang

pig-tail) - Plugged into the auxiliary control

the grip in its stowed position on the hoist control

panel, in the heater compartment at sta 95.

panel. The switches contained in the grip are as

(3) Hoist master switch on the cockpit overhead

follows:

panel - PLT.

4-23

TM 55-1520-240-10

(4) Hoist control switch on cockpit overhead

(5) Winch arming switch on the winch/hoist con-

panel

- OUT, OFF, or IN as required to

trol grip - Depress.

control direction and speed of cable.

(6) Winch cable switch on the winch/hoist control

grip

- OUT, OFF, or IN as required to

Control settings and electrical connections for op-

control direction and speed of the winch

erating the winch in the cargo mode from the cargo

cable.

compartment are as follows:

e. Rigging and operating procedures for use of the

(1)

Cable speed selector lever on the winch -

winch in the cargo mode are as follows:

CARGO.

(1) Using the hoist control switch on the cockpit

(2)

Cable cutter arming device (or adapter cable,

overhead panel or on the winch/hoist control

pig-tail) - Plugged into the auxiliary control

grip - reel out the winch cable as required

panel, in the heater compartment at sta 95.

for rigging. As the cable is being reeled out, a

(3)

Hoist master switch on the cockpit overhead

crewman should maintain tension on the

panel - REMOTE.

cable to avoid snarling and kinking. After the

cable is extended, the usable cable length will

(4)

Winch/hoist control grip - Plugged into ei-

be checked to ensure that the cable is free of

ther the auxiliary control panel in the heater

any broken strands or definite bends that may

compartment, sta 95, the hoist control panel,

reduce the cable capability.

right side sta 320, or the receptacle, left side

sta 502.

(5)

Winch arming switch on the winch/hoist con-

Do not exceed 3,000 pounds single line pull.

trol grip - Depress.

Overload will result in the winch overload

(6) Winch cable switch on the winch/hoist control

switch actuating to stop the winch.

grip

- OUT, OFF, or IN as required to

control direction and speed of winch cable.

(2) Remove the pulley from the pulley blocks by

removing the quick-release pins. Reeve the

Control settings and electrical connections for op-

cable through pulley as required to provide

erating the winch in the

rescue mode from the

the required pull and angle of entry (fig. 4-26

cockpit are as follows:

(Sheet 1 of 2)) for rigging configurations for

(1)

Cable speed selector lever on the winch -

various loads. Install the pulley blocks and

RESCUE.

secure them with the quick-release pins.

(2)

Cable cutter arming device - Plugged into

the overhead receptacle above the rescue

hatch.

The cable quick-disconnect cover guard must

(3)

Hoist master switch on the cockpit overhead

be installed during all cargo operations.

panel - PLT.

Otherwise, the hook assembly can be inad-

vertently disconnected from the winch cable

(4) Hoist cable switch on the cockpit overhead

which can result in serious injury to person-

panel

- OUT, OFF, or IN as required to

nel.

control the direction and speed of the winch

cable.

(3) Attach the winch cable to the cable hook

d. Control settings and electrical connections for op-

assembly by depressing the lock rings on each

erating the winch in the rescue mode from the

end of the quick-disconnect device, inserting

cargo compartment are as follows:

the ball ends of the winch and hook assembly

(1)

Cable speed selector lever on the winch -

cables into the quick-disconnect device and

RESCUE.

releasing the lock rings. Install the quick-

disconnect cover guard.

(2)

Cable cutter arming device - Plugged into

the overhead receptacle above the rescue

(4) Attach the winch cable to the load.

hatch.

(3)

Hoist master switch on cockpit overhead

panel - REMOTE.

Personnel not required for the winching

(4) Winch/hoist control grip - Plugged into the

operation must remain well clear of the

receptacle on the hoist control panel, right

winch cable to prevent possible injury should

side, sta 320.

the cable break.

4-24

TM 55-1520-240-10

block over the rescue hatch (fig. 4-26 (Sheet 2

of 2)).

(3) Reeve the cable through the pulley at each

location by first removing the quick-release

Slack must be removed from the cable train

before applying the fill load to the winch

pin, removing the pulley and positioning the

system to prevent shock and overload of the

cable over the pulley. Reinstall each pulley

system.

and secure with the quick-release pin (fig.

4-26 (Sheet 1 of 2)).

(5) Reel the cable in slowly until all slack in the

cable is removed. Then winch the load into

the cargo compartment to the desired posi-

tion.

Chock vehicles and wheeled cargo before

disengaging cable hook. Injuries to person-

nel can result from uncontrolled rolling of

the load.

(6) Reel out the cable slowly to provide slack in

the cable. The hook can either be left at-

tached to the load or disconnected. If the

hook is disconnected, it should be attached to

a tiedown fitting to prevent in-flight vibra-

tions damage to the cargo floor.

f. Rigging and operating procedures for use of the

winch in the rescue mode are as follows:

NOTE

The cargo hook assembly must be removed

from the rescue hatch.

(1) Using the hoist control switch on either the

cockpit overhead panel or on the winch/hoist

control grip, reel out the winch cable as

required for rigging. As the cable is being

reeled out, a crewman should maintain ten-

sion on the cable to avoid snarling and kink-

ing. After the cable is extended, the usable

cable length will be checked to ensure that

the cable is free of broken strands or definite

bends that may reduce the cable capability.

Some pulley block assemblies have flanges

with cable retainer pins as shown in fig. 4-26

(Sheet 1 of 2). These pins should be installed

only if the cable makes a wrap angle of 180°

or more around the pulley. Otherwise, the

cable will bind on the pins and overload the

winch and cable. When not in use, the pins

and attaching hardware should be stowed in

the container provided for the hoist accesso-

ries.

(2) Install the pulley block assembly on the floor

at sta 140, the overhead on the aft face of sta

120 bulkhead and the cable cutter pulley

Figure 4-26. Hoisting System (Sheet 1 of 2)

4-25

TM 55-1520-240-10

The quick-disconnect cover guard must be

installed during rescue and cargo opera-

tions. Otherwise, the hook assembly can be

inadvertently disconnected from the winch

cable which can result in loss of life or the

load or serious injury to operating person-

nel. For personnel rescue, the cable must

touch the ground or water prior to touching

personnel or a dangerous static electrical

shock may result.

(4) Attach the winch cable to the cable hook

assembly by depressing the lock rings on each

end of the quick-disconnect device, inserting

the ball ends of the winch and hook assembly

cables into the quick-disconnect device and

releasing the lock rings. Install the quick-

disconnect cover guard.

Slack must be removed from the cable train

before applying the full load to the winch

system to prevent shock and overload of the

system and possible injury to the personnel

being hoisted.

Ensure that the load is clear of the ground

and all obstacles before proceeding from

hover to forward flight. Do not exceed

600

pounds. An overload can result in damage or

failure of the support structure for the over-

head cable pulley.

(5) Reel the cable out and attach the cable hook

to load - Reel in or out as required.

g. When electrical power to the winch is not avail-

able, the winch may be operated in emergency

mode as follows:

When the winch is operated in emergency

mode, the cable limit switches are disabled.

To avoid kinking the cable stop the winch

when there is no less than 3 turns of cable on

the drum. Stop reeling the cable in when the

quick-disconnect guard assembly contacts

the pulley and fairlead (fig. 4-18).

(1) Remove electrical connectors from the hoist

control valve and hoist control shutoff valve

on the left bulkhead of the heater compart-

Figure 4-27. Hoist Control Valve and Hoist

ment (fig. 4-27).

Control Shutoff Valve

4-27

TM 55-1520-240-10

(2)

Break the shear wire on the knurled knob of

utility hatch marked CABLE CUTTER. The cable

the hoist control valve.

cutter cartridge is to be checked for total time prior to

any hoisting or rescue operations. The cartridge should

(3)

Push in the plunger on the hoist control

not-be used after

8 years from date of manufacture and

shutoff valve and rotate it 90 degrees to lock

should also be replaced after 1 year of installed service

the valve open.

life. Cartridges are considered over age when either

(4)

Turn the knurled knob on the hoist control

limit is exceeded.

valve clockwise to reel the cable out or coun-

terclockwise to reel it in. Return the knob to

the center (detent) position to stop the winch.

If personnel are in the cargo compartment

(5) When use of the winch is completed, turn the

when a load is jettisoned, make sure that

plunger on the hoist control shutoff valve to

they remain aft of the rescue hatch and face

unlock and extend it.

away from the cable cutter. The hoist cable

4-34. Winching Accessories.

can whip forward when it is cut and particles

can be ejected from the cable cutter.

Accessories are provided for winching and hoisting

operations. Employment of these accessories is deter-

mined by winch usage. A compartment bag is attached

e. Cable Cutter Arming Device.

The arming device

to the bulkhead wall above the winch for stowage of

consists of an electrical wiring harness with electrical

winching accessories.

connectors at either end. This device is used to arm the

cable cutter during hoisting operations. A connector at

a. Cable Pulleys. A sufficient number of pulleys are

one end of the device couples with the threaded recep-

provided to permit routing the winch cable for winching

tacle in the cable cutter; the connector at the other end

and hoisting operations. The pulleys are equipped with

of the device plugs into a receptacle above the utility

snap-lock fasteners for attachment to tiedown fittings or

hatch and is labeled CABLE CUTTER.

shackles as required.

f. Extension Cord.

A 15-foot extension cord is pro-

b. Cable Hook.

A 2-ton-capacity removable hook is

vided to allow mobility of the winch or hoist operator,

provided for use in winching and hoisting operations.

Electrical connectors at each end of the cord connect

Extending from the hook is a length of

¼ inch cable,

with receptacles in the winch control grip and in the

equipped with a metal ball which locks into a quick-

hoist control panel. This cord is the only means of

disconnect device that is used for attaching the hook to

plugging in power to the switches on the control grip.

the cable. The full-swiveling hook contains a spring snap

lock to prevent opening of the hook and accidental loss

g. Safety Harness.

A safety harness is provided for

the hoist operator in operations involving the use of the

of cargo.

rescue hatch. The harness permits complete freedom of

c. Quick-Disconnect Device.

The quick-disconnect

movement while affording a measure of safety in pre-

device permits rapid connecting and disconnecting of

venting the wearer from falling through the door open-

winch cable hooks. The device consists of a short length

ing. The safety harness is attached to a fitting on the

of steel with socket cavities at each end. The sockets are

wall of the cargo compartment near the hoist control

enclosed by spring-loaded rings that rest against flared

panel or a floor tiedown fitting.

rims on either edge of the device. The lockrings are

depressed to admit the ball ends of the cables into the

4-35. Hoisting System.

sockets and snap into place when released, securing the

The hoisting system (fig. 4-26) is used for air rescue and

ball ends of the cables in a positive connection. A guard

for aerial loading of smaller general cargo through the

is supplied with the quick-disconnect device. When

utility hatch. The hoisting system differs from the

installed, it prevents the hoist operator from inadvert-

winching system only in the manner in which the cable

ently operating the quick-disconnect device when assist-

is reeved and the mode selected at the winch. Hoisting

ing a rescued person into the helicopter.

operations require the winch cable to be reeved over-

d. Cable Cutter.

In hoisting operations, there is al-

head and the hoist load capacity to be limited to a

ways a possibility that the cable hook might snag,

maximum of

600 pounds. The winch cable hook is used

resulting in critical strain on the hoisting system and

for hoisting operations together with the cable cutter

restriction of helicopter mobility. The cable cutter pro-

which provides for quick release of the paid out cable

vides a means of quickly severing the snagged hook by

and hook in event of emergency. On those aircraft

cutting the cable. The cable cutter consists of a housing,

provided with pulley block assemblies having pins as

two follower rollers that permit free travel of cable

shown in fig. 4-26 (Sheet 1 of 2), the following instruc-

through the housing, a cutting shell, a ballistic cartridge,

tions apply: When the hoisting system is reeved as

and a threaded receptacle for an electrical connector.

shown in fig. 4-26 (Sheet 2 of 2), the pins and their

The cutter housing is split to allow reeving the cable and

retaining hardware are to be installed only if the cable

is bolted to a pulley bracket through two holes in the

makes a wrap angle of 180° or more around the pulley.

housing. The cable cutter is armed by coupling an

When not in use, the pins and their retaining hardware

arming device to the receptacle in the cutter

^-housing

are to be stowed in the container provided for hoist

and plugging the device into the receptacle above the

accessories.

4-28

TM 55-1520-240-10

to lay on the cargo floor or access door

WARNING

panel during inspection or use. The exces-

sive tension placed on the triple emergen-

To prevent dangerous electrical shock to

cy release cable housing assembly may

personnel being hoisted, the cable must

partially dislodge the housing and engage

touch the ground or water prior to contact-

or activate the forward and aft hook emer-

ing personnel.

gency release mechanism. This may

4-36. Static Line Retriever.

cause an inadvertent release of loaded

forward and aft hook assemblies in flight.

A static line retriever is provided with the static line an-

4-38. Center Cargo Hook. The position of the center

chor cable (fig. 4-28). The retriever is used to haul static

cargo hook is such that the load is suspended beneath

lines into the helicopter at the completion of a paradrop

the CG of the helicopter at sta 331. The hook assembly

mission and can also be used to haul in a paratrooper

consists of a hook, hydraulic actuator, and a release

hung up on a static line. The static line anchor cable and

mechanism. The hook is suspended by means of a beam

retriever are installed and operated as follows:

which is mounted inside the rescue hatch. This beam

a. Install the anchor cable between sta 120 and 592.

rotates within its mounting supports for longitudinal

NOTE

swing. The hook pivots about its attachment bolt for later-

al swing. The cargo hook system is normally operated

Do not allow the cable to sag more than 6

hydraulically by pressure from the utility hydraulic sys-

inches.

tem. In the event of a loss in utility system pressure, the

b. Plug the cable cutter into the auxiliary control pan-

cargo hook can be opened pneumatically or manually.

el at sta 95 and move the speed selector on the winch to

The cargo hook contains a spring-tensioned keeper

CARGO.

which prevents accidental loss of cargo through slippage

of the sling rings. When not in use, the cargo hook can

c. Plug the winch control grip into the power recep-

be removed from the hatch since both the electrical and

tacle at sta 502 on the left side.

hydraulic lines are equipped with quick-disconnectors or

d. Reeve the winch cable through a pulley attached

the cargo hook can be stowed. The cargo hook and beam

to a 5,000-pound tiedown fitting at sta 140, buttline 20 left

assembly must be removed for rescue operations

and then through another pulley attached at sta 120,

through the hatch.

buttline 18 left (fig. 4-28).

4-39. Center Cargo Hook Loading Pole.

e. Reel out enough cable to allow the cable to rest on

the floor and out of the way of personnel. Attach a quick-

disconnect and cover guard to the winch cable.

WARNING

f. When the static lines are ready to be retrieved, reel

out additional cable and attach the retriever to the winch

Make sure the ground cable is connected.

cable. Reel in sufficient cable; then disconnect the static

With the rotors turning, static potential be-

lines from the anchor cable.

tween the helicopter and a load on the

4-37. Triple Cargo Hook System.

ground can be as high as 40,000 volts.

A cargo hook loading pole (fig. 4-29) is provided for pick-

Three external cargo hooks are provided for attaching

ing up the sling loop of external cargo loads from inside

external cargo. The hooks can be used with a single load

the helicopter. The loop is then placed on the cargo hook

on one hook, two hooks in tandem (forward and aft

by hand. The pole has a hook at one end and a cable at

hooks), or individual loads on three hooks. The tandem

the other end. The cable is attached to the fuselage to

hook configuration provides improved load stability at

prevent accidental loss of the pole when in use and to

higher airspeeds. With the triple hook system, up to three

provide a discharge path for static electricity. When not

loads can be deposited at different locations during a

in use, the pole is stowed on the lower right side of the

single mission. The forward hook is at sta 249. The cen-

cabin at about sta 360.

ter hook is at sta 331. The aft hook is at sta 409.

4-40. Forward and Aft Cargo Hooks.

All hooks have normal release modes, emergency re-

lease modes, and manual release modes. Normal re-

The forward and aft cargo hooks (fig. 4-31) are at-

lease mode can be controlled by both pilots or by the

tached to bottom centerline of the helicopter at sta 249

hoist operator. Emergency release of all hooks can be

and 409. Unlike the center hook, these hooks are not

performed electrically by either pilot or manually by the

accessible to the crew in flight. Both hooks have elec-

crew member.

trical normal and emergency release mechanisms. The

normal mechanisms can be operated by either pilot or

by the hoist operator. In an emergency, both hooks can

CAUTION

also be released from the cockpit through a dedicated

emergency release circuit or manually by the hoist

Do not lift or rotate the center cargo hook

operator. A knurled knob on the side of each hook

into the cabin area or allow the mid hook

allows the hook to be opened by a ground crewman. A

Change 18

4-29

TECHNICAL MANUAL MAINTENANCE MANUAL FOR ARMY CH-47D HELICOPTER (1992) - page 8