HANDBOOK OF MAINTENANCE INSTRUCTIONS FOR MDHI 369D/E/FF-500/600N HELICOPTERS (ISSUED: 1990)

MD Helicopters, Inc.

CSP-HMI-2

MAINTENANCE MANUAL

L. Post−Installation Inspection

(5). Clean all debris from mast area.

(6). Install modified engine cooling air inlet

Consumable Materials

screen (Ref. Figure 903, detail B).

(Ref. Section 91−00−00)

(7). Install engine air inlet forward fairings.

Item

Nomenclature

Seal gap between reworked area of left

CM209

Zinc chromate putty

fairing and door cable with zinc

chromate putty (CM209) as required.

(1). Inspect all installation brackets, clamps

(8). Install all interior trim.

and fasteners for security.

(9). Check bypass door rigging (Ref. Air

(2). Check electrical wiring connectors,

Bypass Door Rigging).

clamps and attaching hardware for

(10). Perform a particle separator operation

proper installation and security.

al check (Ref. Scavenge Air Operational

Failure to inspect and thorough

Check).

CAUTION

ly clean debris from engine inlet

(11). Revise weight and balance records.

areas will result in engine FOD.

M. Weight and Balance

(3). Inspect plenum chamber for cleanli

ness. Remove all traces of debris with a

Weight and balance changes resulting from

vacuum cleaner.

installation of the particle separator are listed

in Table 901. Incorporate changes in helicopter

(4). Remove engine inlet covers.

weight and balance records.

Table 901. Weight and Balance Data

Configuration

Weight

Arm

Moment

Pounds (kg)

inches (cm)

in−lb (kg cm)

369H90148−503

10.8

(4.8987968)

124.2

(315.468)

13.4

(154.38408)

369H90148−505

13.5

(6.123496)

125.1

(317.754)

16.9

(194.70828)

369H90148−507

10.8

(4.8987968)

122.6

(311.404)

13.2

(152.07984)

369H90148−509

12.3

(5.5791852)

122.8

(311.912)

15.2

(175.12224)

369H90148−519

17.0

(7.7110691)

124.8

(316.992)

21.3

(245.40156)

369H90148−521

18.6

(8.4368167)

125.4

(318.516)

23.3

(268.44396)

369H90148−527

17.0

(7.7110691)

124.8

(316.992)

21.3

(245.40156)

369H90148−529

18.6

(8.4368167)

125.4

(318.516)

23.3

(268.44396)

500N90148−1 /−3

18.6

(8.4368167)

125.4

(318.516)

23.3

(268.44396)

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CSP-HMI-2

MAINTENANCE MANUAL

ENGINE AIR PARTICLE SEPARATOR

DESCRIPTION AND OPERATION

Description and Operation

from a switch in the cockpit and bleed

air comes from the cabin heat system.

(1). The optional engine air particle separa

Pressure from the bleed air draws the

tor is mounted above the engine air

dirt out of the particle separator and

inlet plenum. Intake air is cleaned by

exhausts it through the ejectors.

the particle separator to prevent dirt or

foreign objects from entering the

(4). A differential pressure switch is

engine.

mounted with a reference to inside and

outside of the particle separator.

(2). Dirt is separated from the intake air by

Blockage of the particle separator will

centrifugal force created by the particle

cause a pressure decrease on the engine

separator vortex tubes. Clean air passes

plenum side and the switch will

through the tubes to the engine inlet

activate a warning light in the cockpit.

plenum.

(5). A cable from the cockpit is manually

(3). The separated dirt is removed from the

operated to open an engine bypass door

inside of the particle separator with

which allows unfiltered air into the

pressurized engine compressor bleed

engine inlet plenum if the particle

air. A solenoid shutoff valve is activated

separator is blocked.

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MD Helicopters, Inc.

CSP-HMI-2

MAINTENANCE MANUAL

ENGINE AIR PARTICLE SEPARATOR

REMOVAL/INSTALLATION

1. Particle Separator Replacement

(3). Remove bolts, washers and solenoid

valve.

(Ref. Figure 401)

B. Scavenge Air Solenoid Valve Installation

A. Particle Separator Removal

(1). Install solenoid valve with bolts and

(1). Remove left and right particle separator

washers. Torque bolts to 20 - 25

access panels.

inch-pounds (2.25 - 2.82 Nm).

(2). Connect tube nuts to solenoid valve.

(2). Disconnect left and right bleed air

Torque tube nuts to 110 - 130 inch-

tubes from particle separator.

pounds (12.42 - 14.68 Nm).

(3). Remove screws and washers attaching

(3). Attach electrical connector to solenoid

left and right ejectors to particle

valve.

separator.

3. Air Filter Bypass Switch Replacement

(4). Remove screws and washers and lift

particle separator from top of engine

A. Air Filter Bypass Switch Removal

inlet frame.

(1). Detach electrical wires at splices.

B. Particle Separator Installation

(2). Disconnect tube nut from switch.

(1). Install particle separator on top of

engine inlet frame with screws and

(3). Remove jam nut, washer and switch.

washers. Torque screws to 20 - 25

B. Air Filter Bypass Switch Installation

inch-pounds (2.25 - 2.82 Nm).

(1). Install switch with jam nut and washer.

(2). Attach left and right ejectors with

Torque jam nut to 65 - 80 inch-

screws and washers. Torque screws to

pounds (7.34 - 9.03 Nm).

20 - 25 inch-pounds (2.25 - 2.82

Nm).

(2). Connect tube nut to switch. Torque nut

to 25 - 35 inch-pounds (2.82 - 3.95

(3). Connect left and right bleed air tubes to

Nm).

particle separator. Torque particle

separator tube nuts to 460 - 500

(3). Attach electrical wires with splices.

inch-pounds (51.96 - 56.48 Nm).

4. Bypass Door Assembly Replacement

(4). Install left and right particle separator

access panels. Torque screws to

A. Bypass Door Assembly Removal

(1). Remove cotter pin and clevis pin and

2. Scavenge Air Solenoid Valve

disconnect bypass door linkage.

Replacement

(2). Drill out rivets and remove bypass door

(Ref. Figure 401)

assembly.

A. Scavenge Air Solenoid Valve Removal

B. Bypass Door Assembly Installation

(1). Detach electrical connector from

(1). Install bypass door assembly with

solenoid valve.

rivets.

(2). Disconnect tube nuts from solenoid

(2). Connect linkage with clevis pin and

valve.

cotter pin.

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MAINTENANCE MANUAL

5. Bypass Door Cable Assembly

(2). Remove access door from side of

Replacement

particle separator.

A. Bypass Door Cable Assembly Removal

NOTE: There area eight rivets securing the

manifold in place. Four rivets secure the

(1). Remove cotter pin and clevis pin from

flange and four rivets, two per side, secure

bellcrank and cable end.

the tubes.

(2). Disconnect mounting clamps and

remove cable assembly.

(3). Remove rivets securing manifold and

remove from particle separator.

B. Bypass Door Cable Assembly Installation

Debris left in particle separator

(1). Install cable assembly and connect

CAUTION

must be removed to prevent

mounting clamps.

damage to engine.

(2). Install clevis pin through cable end and

bellcrank. Safety clevis pin with cotter

(4). Clean area thoroughly of any metal

pin.

shavings.

6. Bypass Door Seal Repair

(5). Thoroughly wipe rework area with

clean cloth dampened with solvent

(1). Drill out rivets attaching door stop and

(CM234) and allow to air dry.

seal to frame. Remove door stop with

seal.

(6). Install new manifold is particle separa

(2). Remove damaged seal.

tor.

(3). Clean faying surfaces.

(a). Secure with eight CR3212-4-2 (or

equivalent) rivets wet with primer

(4). Install new seal on door stop.

(CM318).

(5). Install door stop and seal with rivets.

Ensure rivets are properly

CAUTION

7. Particle Separator Manifold Replacement

installed to prevent damage to

engine.

(Ref. PA CD-01062-1D8L/R)

(b). Thoroughly clean heads of rivets and

(Ref. Figure 401) The following procedure is for

surrounding area with solvent

field replacement of the Pall Aerospace

(CM234) and allow to air dry.

particle separator manifold.

(c). Apply a small amount of sealing

Consumable Materials

compound (CM425) to seal rivet head

(Ref. Section 91−00−00)

to particle separator.

Item

Nomenclature

CM234

Solvent, dry-cleaning

(d). Allow sealing compound to cure

CM318

Primer

before reinstalling particle separator

CM425

Sealing compound

on helicopter.

(7). Reinstall access door on side of particle

Prevent engine FOD. Secure a

separator.

CAUTION

cover over the engine intake

prior to working inside plenum chamber.

(8). Remove cover from engine inlet.

Remove cover after completing work.

(1). Remove particle separator (Ref. Particle

(9). Reinstall particle separator (Ref.

Separator Replacement).

Particle Separator Replacement).

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MD Helicopters, Inc.

CSP-HMI-2

MAINTENANCE MANUAL

ENGINE AIR PARTICLE SEPARATOR

INSPECTION/CHECK

Engine Air Particle Separator Inspection

2. Bypass Door Inspection

(1). Visually inspect particle separator for

(1). Visually inspect bypass door stop for

damage and security of installation.

damage to seals. Replace damaged

seals.

(a). Inspect particle separator panel for

(2). Inspect bypass door hinges for opera

damage to axial flow dust separator

tion and security. Replace or repair as

tubes. No damage allowed.

required.

(b). Inspect particle separator for security

3. Bypass Door Cable Inspection

of installation. Torque or replace

loose or missing hardware.

(1). Visually inspect bypass door cable for

operation and security. Replace inoper

(c). Open access panels and inspect bleed

able cable. Torque or replace loose or

air tubes for security. Torque tube

missing hardware.

nuts.

(2). Visually inspect linkage for cracks,

(d). Inspect ejectors for security. Torque

deformation and security of hardware.

or replace loose or missing hardware.

Replace damaged linkage. Replace

missing hardware.

(2). Visually inspect bypass door for damage

and security of installation.

4. Air Pressure Sensing Switch Calibration

Check

(a). Open bypass door and inspect seal for

damage or leakage. None allowed.

(1).

Assemble test equipment (Ref.

Figure 601).

(b). Inspect bypass door for security of

(2).

Attach pressure switch to test equip

installation. Torque or replace loose

ment. Connect a suitable vacuum

or missing hardware.

source to pressure switch nipple and

u-tube.

(3). Visually inspect air filter bypass switch

for damage and security of installation.

(3).

Connect an ohmmeter or continuity

tester to pressure switch electrical

(a). Inspect switch for security. Torque

leads.

loose hardware.

(4).

Cycle switch from open to close several

(b). Inspect electrical wiring for chafing

times with vacuum. Watch meter for

or cuts. None allowed. Ensure

indication of switch closure. Release

connections are secure.

vacuum.

(4). Visually inspect scavenge air solenoid

(5).

Slowly apply vacuum. Note u-tube

valve for damage and security of

water height differential in both legs of

installation.

the tube relative to the switch closing

point. The total of the differential

(a). Inspect solenoid valve for security of

heights of both legs of the u-tube is

installation. Torque or replace loose

equal to switch actuation pressure.

or missing hardware.

(6).

Switch closing pressures shall be per

(b). Inspect electrical wiring for chafing

the applicable particle separator

or cuts. None allowed. Ensure

installation dash number shown (Ref.

connections are secure.

Figure 601).

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MD Helicopters, Inc.

CSP-HMI-2

MAINTENANCE MANUAL

ENGINE MOUNTS

DESCRIPTION AND OPERATION

1. Description

D Unless otherwise required, remove and

replace only one engine mount at a time.

(1). The engine is bolted to the helicopter

D Do not disturb adjustable engine mount

airframe with one lower and two upper

fittings unless an engine-transmission

tubular steel, welded mount assem

alignment check is planned.

blies. Engine loads are transferred

through the mounting system into the

D Use box-end and socket wrenches on

airframe through six fittings and

mounting system hardware. Do not nick

special attaching fasteners. Left and

or scratch any of the mounting system

right upper engine mount assemblies

fasteners.

effect engine-transmission alignment

and may be adjusted by means of

2. Airframe Fittings

threaded fittings that are a part of each

(1). Airframe-engine mount structural

mount leg.

attach fittings and hoist fitting are

removed or replaced per the Structural

CAUTION

Repair Manual (SRM).

D Engine-transmission alignment shall be

NOTE: Structural attach fittings shall not be

inspected and adjusted whenever one or

removed unless structural damage is evi

more of the engine mount assemblies is

dent or engine-transmission misalignment

replaced or the existing adjustment is dis

is suspected as a result of a damaged struc

turbed.

tural fitting. Prior to attempting fitting re

D Do not remove engine mounts to remove

placement perform an engine-transmission

the engine.

alignment check per the SRM.

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Revision 22

MD Helicopters, Inc.

CSP-HMI-2

MAINTENANCE MANUAL

ENGINE MOUNTS

REMOVAL/INSTALLATION

1. Airframe Fittings Replacement

NOTE: All engine mount fitting bolts, washers

and nuts are corrosion resistant steel.

Remove/install airframe structural attach

fittings only if structural damage is present

(1). Install lower engine mount on bulkhead

per the Structural Repair Manual (SRM).

fittings with two bolts, four washers

and two new nuts.

2. Lower Engine Mount Replacement

(2). Install engine-mount attach bolt and

(250−C20/−C20R/2)

washer. Torque bolt to 100 - 140

A. Lower Engine Mount Removal

inch-pounds (11.30 - 15.82 Nm);

(250−C20/−C20R/2)

Lockwire installation.

(3). Torque airframe fitting hardware at

(Ref. Figure 401)

firewall to 50 - 70 inch-pounds (5.56

- 7.91 Nm) plus drag torque.

Special Tools

(Ref. Section 91−00−00)

3. Upper Engine Mounts Replacement

Item

Nomenclature

(250−C20/−C20R/2)

ST402

Engine hoist

A. Upper Engine Mounts Removal

(250−C20/−C20R/2)

(1).

Remove hardware attaching air duct

(Ref. Figure 401)

support bracket to overhead engine

hoist fitting.

(1). On upper right engine mount; unclamp

and move wire harness.

(2).

Install engine hoist (ST402). Back off

mount nuts 1/2 turn. Tension hoist to

(2). Remove gear case cooling duct clamp

relieve engine weight on lower mount

from left engine mount.

until bolts will turn freely.

(3). Disconnect upper mount forward attach

(3).

Release cargo compartment trim and

points from airframe fittings. Discard

upholstery to gain access to bolt-heads

nuts.

at bulkhead fitting.

(4). Disconnect aft ends of mounts from

(4).

Disconnect left and right forward ends

engine fittings.

of lower engine mount. Discard both

B. Upper Engine Mounts Installation

nuts.

(250−C20/−C20R/2)

(5).

Detach lower engine mount from engine

(Ref. Figure 401)

fitting.

Do not tighten airframe-mount

B. Lower Engine Mount Installation

CAUTION

bolts until engine fitting-mount

(250−C20/−C20R/2)

bolt is tightened.

(Ref. Figure 401)

NOTE: All engine mount fitting bolts, washers

and nuts are corrosion resistant steel.

CAUTION

(1). Install two bolts, four washers and two

new nuts to fasten mounts to airframe

D Do not tighten airframe-mount bolts un

fittings.

til engine fitting-mount bolt is torqued.

D If a new engine-mount fitting has been

NOTE: Retorque engine attach bolt after 3 to 5

installed; retorque engine-mount attach

hours flight time following a new engine

bolt after 3 to 5 hours of flight time.

mount fitting installation.

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CSP-HMI-2

MAINTENANCE MANUAL

(2).

Install engine-mount washer and bolt.

B. Lower−Aft Engine Mount Installation

Torque bolt to 100 - 140 inch-pounds

(250−C30/−C47)

(11.30 - 15.82 Nm).

(Ref. Figure 402)

(3).

Torque upper engine mount fitting

hardware at firewall and landing gear

CAUTION

damper support to 30 - 40 inch-

pounds (3.39 - 4.52 Nm) plus drag

D Do not tighten airframe-mount bolts un

torque.

til engine fitting-mount bolt is torqued.

D If a new engine-mount fitting has been

(4).

Repeat the appropriate steps to install

installed; retorque engine-mount attach

the remaining upper engine mount.

bolt after 3 to 5 hours of flight time.

(5).

Remove engine hoist.

NOTE: All engine mount fitting bolts, washers

and nuts are corrosion resistant steel.

(6).

Install wire harness clamp on right

engine mount.

(1). Place ends of lower engine mount

against bulkhead fittings.

(7).

Install compressor air duct support

(2). Install aft engine mount as shown; use

bracket on airframe hoist fitting. Install

two bolts, four washers and two new

gear case cooling duct clamp on left

nuts at bulkhead attach fittings.

engine mount (Ref. Sec. 71-60-00).

(3). Install engine-mount attach bolt

Lower−Aft Engine Mount Replacement

washers and new nut. Torque nut to 95

(250−C30/−C47)

- 110 inch-pounds (10.73 - 12.43

Nm) plus drag torque. Install cotter

pin as required.

A. Lower−Aft Engine Mount Removal

(250−C30/−C47)

(4). Torque airframe fitting hardware at

Sta. 137.50 to 95 - 110 inch-pounds

(Ref. Figure 402)

(10.73 - 12.43 Nm) plus drag torque.

5. Upper Engine Mounts Replacement

Special Tools

(250−C30/−C47)

(Ref. Section 91−00−00)

Item

Nomenclature

A. Upper Engine Mounts Removal

ST402

Engine hoist

(250−C30/−C47)

(Ref. Figure 402)

(1).

Remove hardware attaching upper

cooling air duct support bracket to

(1). Remove gear case cooling duct clamp

overhead engine hoist fitting.

from left side engine mount.

(2). Disconnect upper mount forward attach

(2).

Install engine hoist (ST402). Back off

points from airframe fittings. Discard

mount nuts 1/2 turn. Tension hoist to

nuts.

relieve engine weight on aft mount

until bolts will turn freely.

(3). Disconnect aft ends of mounts from

engine fittings.

(3).

Detach aft engine mount from engine

fitting.

B. Upper Engine Mounts Installation

(250−C30/−C47)

(4).

Disconnect left and right forward ends

of aft engine mount. Discard nuts.

(Ref. Figure 402)

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CSP-HMI-2

MD Helicopters, Inc.

MAINTENANCE MANUAL

(2). Install engine-mount washer and bolt.

CAUTION

Torque bolt to 220 - 360 inch-pounds

(24.86 - 40.67 Nm); lockwire bolt.

D Do not tighten airframe-mount bolts un

til engine fitting-mount bolt is torqued.

(3). Torque upper engine mount fitting

hardware at firewall and landing gear

D If a new engine-mount fitting has been

damper to 60 - 85 inch-pounds (6.78

installed; retorque engine-mount attach

- 9.60 Nm) plus drag torque.

bolt after 3 to 5 hours of flight time.

(4). Repeat the appropriate steps to install

NOTE: All engine mount fitting bolts, washers

the remaining upper engine mount.

and nuts are corrosion resistant steel.

(5). Remove engine hoist.

(1). Install two bolts, four washers and two

new nuts to fasten mounts to airframe

(6). Install gear case cooling duct clamp on

fittings.

left engine mount.

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MD Helicopters, Inc.

CSP-HMI-2

MAINTENANCE MANUAL

ENGINE MOUNTS

INSPECTION/CHECK

Engine Mounts and Fittings Inspection

2. Upper Engine Mounts Adjustment

(1).

Inspect painted surfaces of engine

NOTE: Do not disassemble upper engine

mounts for condition.

mounts except for spares replacement or

magniflux inspection.

(2).

Inspect all engine mount tubes for

straightness. Hold steel straight edge

(1). Engine realignment is required when:

against tubes to reveal any warps or

(a). Mount assembly is from another

bends in tubes.

helicopter.

(3).

Check that jam nuts and lockwire on

mounts with adjustable fittings are

(b). One upper mount has been replaced.

secure and not disturbed. If not secure

(c). One upper mount adjustment has

or adjustment is disturbed, a check of

been disturbed.

engine-to-transmission alignment is

required per the Structural Repair

(2). Check engine-transmission alignment

Manual (SRM).

per the Structural Repair Manual

(SRM) and realign a reassembled or

(4).

Visually inspect all tubes and welded

cannibalized mount assembly.

joints for cracks and evidence of

corrosion. Magnetic-particle inspect

(3). Engine transmission realignment is

suspected engine mount assemblies. If

accomplished by adjusting the upper

crack(s) are evident, mount is unser

engine mounts using the tool specified

viceable.

by SRM instructions and as follows:

(5).

Inspect flanges and bosses of engine

(a). Adjust mounts to align engine with

mount fittings and lifting eye for

transmission. Tighten jamnuts and

flatness, cracks and corrosion. Replace

recheck alignment.

defective fittings.

(b). Lockwire jamnuts.

(6).

Inspect threaded steel insert for

damaged threads, corrosion and for full

(c). Paint a slippage mark across both

bottoming to seat of insert hole.

jamnuts on each leg.

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MD Helicopters, Inc.

CSP-HMI-2

MAINTENANCE MANUAL

ENGINE MOUNTS

REPAIRS

1. Engine Mount Repairs

(3). Perform an engine-transmission

alignment check per the Structural

Accomplish minor repairs as instructed below;

Repair Manual (CSP-SRM-6).

otherwise, replace defective engine mounts

that are cracked, twisted, bent or exceed

(4). A repaired mount shall be replaced

acceptable attach hole tolerances.

when engine-transmission misalign

ment occurs as a result of repair.

2. Mount Hole Repair (250−C20/−20R/2)

NOTE:

Upper engine mounts incorporate close

D Drilling one mount hole to the maximum

tolerance holes. Hole tolerances must be

0.3170 inch diameter does not normally

maintained within limits to get correct

cause misalignment beyond tolerance.

engine-transmission alignment.

D If both mounts are reworked, engine-

(1). Engine attachment hole diameter

transmission alignment must be checked.

normally is 0.3122-0.3132 inch

(7.92988-7.95528 mm).

3. Painted Surfaces Repair

(2). Ream a damaged hole to 0.3170 inch

(1). Repaint otherwise undamaged surfaces

(8.0518 mm) diameter maximum.

as necessary (Ref. Sec. 20-30-00).

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MD Helicopters, Inc.

CSP-HMI-2

MAINTENANCE MANUAL

ENGINE IGNITION CONTROL SYSTEM

DESCRIPTION AND OPERATION

Engine Ignition System Description and

Secondary ignition circuit

WARNING

Operation

voltage is lethal. Set battery

switch OFF, disconnect battery and ex

ternal power before working on sys

(1). The engine ignition system consists of

tem. Insulate all bare wires and cable

switches, wiring, ignition exciter and an

as required.

igniter plug.

2. Automatic Re−ignition System

Description and Operation

(2). Engine ignition power may be provided

(Ref. Figure 401) Engine automatic re-ignition

by the helicopter battery or external

equipment is installed on all Model 369D

auxiliary power as selected by battery

helicopters subsequent to S/N 1149 and all

switch position. Later helicopters are

369E/FF and 500N helicopters. The equipment

equipped with a standard start circuit

consists of a two-switch, four-lamp, indicating

breaker that may be installed on earlier

latching cluster (XDS9), and a toggle switch

machines.

(S11) for operational testing of the re-ignition

system, mounted on the lower left side of the

instrument panel face. Relays K104 and K304,

Refer to the Pilot's Flight Manu

and a diode isolator assembly (CR1 and CR2)

CAUTION

al for specific engine start proce

is located in the engine bay on the aft oleo

dures.

support fitting.

NOTE:

(3).

Placing the battery switch in either

D For information relative to optional auto

EXT PWR or BAT with the key switch

matic re-ignition equipment installed on

on, arms the start system. Pressing the

369D helicopters prior to S/N 1150, refer

START switch on the collective stick

to Auto Re-ignition Initial Installation.

applies 24 Vdc to the starter/generator

D For Instructions on modification to re-ig

and ignition exciter. The starter/genera

nition equipment for full time operation

tor motors the engine gas producer to

(Applicable to 369D helicopters, S/N 003 -

start speed while the exciter simulta

949 only), refer to Auto Re-ignition Modi

neously provides a high voltage spark

fication.

across the igniter plug gap. At about

D On 369E helicopters 384 and subs, and

15% rpm, fuel is added to the sequence

369FF helicopters 076 and subs auto re-

by moving the throttle out of cutoff to

ignition system has new design and op

idle. START button release de-ener

erational differences.

gizes the ignition exciter and starter/

generator.

D On 369E helicopter S/N 384 - 508, 369FF

helicopter S/N 076 - 091, and 500N heli

copters S/N 001 - 044 addition of air/

(4).

See the Allison Engine Operation and

ground switch S522 and terminal boards

Maintenance manual for specific

TB1001 and TB1003 are used. Relay

K304 and diodes CR1 and CR2 (located in

ignition system maintenance informa

the engine bay on the oleo panel) isolators

tion.

are not used.

D On 369E helicopters 509 & subs, 369FF

(5).

Refer to Auto Re-ignition for wiring

helicopters 092 & subs, and 500N helicop

data on the standard and automatic

ters 045 & subs the air/ground switch has

ignition system option.

been removed.

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MAINTENANCE MANUAL

(1).

The Automatic re-ignition is initiated

(6).

Rotor/oil pressure switch S203 auto

when the Engine Power Out Warning

matically arms the audio circuitry with

(EPO) Unit senses an N₁ speed of less

pressure.

than 55 percent or an N_R speed of less

(7).

As the throttle is increased to the flight

than 98 percent (369D/E model helicop

idle position, the N_R sensing function is

ters) or 95 percent (369FF and 500N

enabled after a time delay of 3.5

model helicopter).

seconds. The N_R sensing function

(2).

When the EPO unit senses one or both,

remains enabled until the throttle is

re-ignition relay (K104) closes, which

decreased through the ground idle

completes a 28 volt circuit to the

position.

ignition exciter (SQ300), generating

(8).

A re-ignition test switch, S11, provides

high voltage across the igniter. In

a ground test of the auto re-ignition

addition, audible and visual warning

circuit. RE-IGN TEST switch S11

circuits are energized.

provides ground test of the auto

(3).

The auto re-ignition relay is de-ener

re-ignition circuit by bypassing the

gized when the EPO unit senses the

main transmission pressure switch,

appropriate N₁ and N_R speeds.

closing relay K104 to energize the

igniter.

(4).

Pressing a reset button resets the

(9).

ENG OUT audio alarm only is disabled

warning light circuit (relay K304

when the generator switch is OFF (On

opens).

369E helicopter S/N 384 - 508, 369FF

(5).

Automatic re-ignition is prevented

helicopter S/N 076 - 091, and 500N

during normal start-up and shutdown

helicopters S/N 001 - 044 audio

by an N_R disable switch which senses

warning is disabled by air/ground

throttle position.

switch S522).

Page 2

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CSP-HMI-2

MAINTENANCE MANUAL

ENGINE IGNITION CONTROL SYSTEM

FAULT ISOLATION

1. Engine Ignition System Fault Isolation

NOTE: All troubleshooting presumes wire seg

ment continuity checks for OPEN or

(Ref. Table 101)

SHORT circuit conditions have been com

Before removing or install

pleted and indicator lamps are known to be

WARNING

ing components of the elec

good.

trical system, ensure all electrical pow

er is OFF. Serious injury or death can

result from voltage potentials in the ig

nition exciter. Voltages in other electri

cal system components can injure per

sonnel.

Table 101. Ignition System Fault Isolation

Symptom

Probable Trouble

Corrective Action

Engine will not start (starter

Oil fouled igniter plug

Attempt a second start.

operation normal)

Faulty ignition circuitry

Listen for spark igniter operation.

Check for fuel vapor from exhaust.

No power to ignition exciter due to

Replace defective switch or wiring.

faulty key switch, start switch or

wiring

Spark igniter fouled, grounded or

Clean or replace igniter plug.

open

Faulty high tension lead

Replace lead.

Igniter plug firing intermittently

Check exciter input voltage. Install

an operational exciter and test

ignition system.

Starter/generator does not motor

Circuit breaker open

Reset/replace circuit breaker.

engine when START switch is

Low battery voltage

Crank engine with an APU or charge

pressed

battery.

Defective start relay

Replace relay.

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MAINTENANCE MANUAL

2. Automatic Re−ignition System Fault

NOTE: All troubleshooting presumes wire seg

Isolation

ment continuity checks for OPEN or

SHORT circuit conditions have been com

(Ref. Table 102 and Table 103)

pleted and indicator lamps known to be

Before removing or install

good.

WARNING

ing components of the elec

trical system, ensure all electrical pow

er is OFF. Serious injury or death can

result from voltage potentials in the ig

nition exciter. Voltages in other electri

cal system components can injure per

sonnel.

Table 102. Automatic Re−ignition System Fault Isolation (369D)

Symptom

Probable Trouble

Corrective Action

System functions normally, but

Defective lamp

Replace lamp XDS9.

RE−IGN lamps do not illuminate

Defective switch XDS9

Replace indicator switch XDS9.

Defective relay K304

Replace relay K304.

Start relay (K301) is energized

Diode CR2 defective, or START

Replace diode CR2 or diode isolator

during automatic re−ignition

switch (S106) closed

assembly or check START switch

and wiring for short circuit.

Equipment fails to function with 28

Relay K104 defective

Replace relay K104.

Vdc present at terminals D and E

of terminal board TB503−3 and

ARMED lamps illuminated

ARMED lamps not illuminated and

Switch S11 defective

Replace switch S11.

equipment fails to function with 28

Vdc at terminals D and E of

terminal board TB503−3

ARMED lamps not illuminated, but

Relay K304 and/ or lamps

Replace lamps and/or relay K304.

equipment functions

defective

ARMED and RE−IGN lamps

Diode CR1 defective

Replace diode CR1 or diode isolator

illuminated, 28 Vdc present at

assembly.

terminal 1 of diode CR1, but less

than 26 Vdc at terminal 2 of diode

CR1 and automatic re−ignition fails

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CSP-HMI-2

MAINTENANCE MANUAL

Table 103. Automatic Re−ignition System Fault Isolation (369E/FF − 500N)

Symptom

Probable Trouble

Corrective Action

RE−IGN TEST switch ON, RE−IGN

Faulty diode CR1

Replace diode or diode isolator

P RST indicator lit, 28 Vdc present

assembly.

at pin 1 of CR1 (diode isolator

assembly) but less than 28 Vdc

present at pin 2 of CR1. Automatic

re−ignition does not occur

RE−IGN TEST switch ON, 28 Vdc

Faulty re−ignition relay K104

Replace re−ignition relay K104.

present at pin L of TB503−9.

Automatic re−ignition does not

occur

RE−IGN TEST switch ON, 28 Vdc

Faulty RE−IGN TEST switch S11

Replace RE−IGN TEST switch S11.

present at pin 6 of TB503−10.

Automatic re−ignition does not

occur and RE−IGN P RST indicator

does not light

Auto re−ignition system functions

Defective lamp

Replace lamp XDS9.

normally but RE−IGN P RST

Defective switch XDS9−S2

Replace indicator switch XDS9.

indicator does not light

Defective relay K304

Replace relay K304.

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MAINTENANCE MANUAL

ENGINE IGNITION CONTROL SYSTEM

REMOVAL/INSTALLATION

1. Automatic Re−ignition System

Lampholder assembly has a po

CAUTION

Component Replacement

larizing key, and can only be in

stalled one way. Do not attempt to force it to

(Ref. Figure 401 thru Figure 403) Replace

seat.

affected components of the automatic re-igni

tion system as indicated in the following

(4). Insert new lamp into lampholder and

procedures.

reinstall lampholder assembly into

housing.

Ensure all electrical power

WARNING

D. Armed Lights/Switch (XDS9) Display

is OFF during removal and

replacement of electrical components.

Screen Replacement

(1). Pull screen and lampholder assembly

A. Automatic Re−ignition Test Switch (S11)

out of housing.

Replacement

(2). Remove screen by sliding it to left or

Replace switch per Control Switches Replace

right.

ment (Ref. Sec. 96-30-00).

(3). Slide replacement screen into position.

B. Armed Light/Switch (XDS9) Assembly

Replacement

Lampholder assembly has a po

CAUTION

larizing key, and can only be in

(1). Remove four screws and washers

stalled one way. Do not attempt to force it to

securing adapter plate to instrument

seat.

panel.

(4). Re-insert screen and lampholder

(2). Pull entire assembly away from panel.

assembly into housing.

(3). Remove nut, washer and screw secur

E. K104/K304 Relay Replacement

ing clamp to switch and push housing

through adapter plate.

Replace relays K104 and/or K304 as follows:

(4). Hold switch with one hand and housing

with other hand and apply breakaway

Consumable Materials

pressure to force two spring fingers on

(Ref. Section 91−00−00)

housing to release switch.

Item

Nomenclature

CM815

Solder

(5). Remove wires from defective compo

nents and reconnect to replacement

component as required.

(1). Remove nuts, four washers and two

screws attaching relay to mounting

(6). Reassemble components in reverse

bracket.

order of disassembly.

(2). Pull relay forward until wiring at back

C. Armed Light/Switch (XDS9) Lamps

of relay is accessible.

Replacement

(3). Note location of each wire and remove

(1). Pull display screen and lampholder

from back of relay.

assembly out of housing.

(4). Using solder (CM815) connect wires to

(2). Slide defective lamp out of lampholder.

new relay.

(3). Remove filter from defective lamp and

(5). Reinsert wiring and relay, and attach to

slip it over glass envelope of new lamp.

bracket with screws, washers and nuts.

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MAINTENANCE MANUAL

F. CR1/CR2 Diode Replacement

ring, mica washer and flat washer in

place between bus and bracket.

Consumable Materials

(5). Insert threaded end of diode through

(Ref. Section 91−00−00)

bracket, ring, washers and bus. Install

Item

Nomenclature

terminal (CR1 only) and lockwasher on

CM313

Insulation varnish

threaded end of diode and secure with

AN316-4 nut. Do not use nut supplied

with diode.

(1). Open engine access doors.

(2). Remove lead wire from diode to be

(6). Reinstall terminal on diode with screw,

replaced by removing nut, two washers

two washers and nut.

and screw.

(7). Perform operational test of system

(3). Remove nut, lockwasher and terminal

(refer to applicable Pilot's Flight

(CR1) from diode. Holding flat washer,

Manual.

mica washer, and insulating ring under

bus, remove diode and mica washer

(8). After successful test, apply glyptol

from opposite side of bracket. Remove

(CM313) to exposed threads and tip of

washers and ring from under bus.

new diode.

(4). Install mica washer on threaded end of

replacement diode and hold insulating

(9). Close and secure engine access doors.

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CSP-HMI-2

MAINTENANCE MANUAL

INSTRUMENT

PANEL

INST. CB101

ENG. OUT CB106

CIRCUIT BREAKER

AUTO RE-IGNITION

PANEL

(NOTES 2, 3)

RE-IGNITION PANEL

LOWER SWITCH AND CIRCUIT

(NOTE 1)

BREAKER PANEL

INSTRUMENT PANEL (SLIM LINE)

RELAY

K304

RELAY

BRACKET

K104

(NOTES 1, 2)

RELAY

K103

NOTES:

RELAY

EFFECTIVE SHIPS 369D SERIAL NOS. 3 THRU 949.

K104

EFFECTIVE SHIPS 369D SERIAL NOS. 950 THRU 1148.

RELAY

EFFECTIVE SHIPS 369D SERIAL NOS. 1150 AND SUBS

K304

(WITH AUTO RE-IGNITION INSTALLED).

EFFECTIVE SHIPS 369E/FF - 500N.

EFFECTIVE SHIPS 369FF ONLY.

REAR VIEW (NOTE 3)

SWITCH ASSEMBLY ARRANGEMENT VARIES WITH

HELICOPTER MODEL.

EFFECTIVE 369E, 001 THRU 383; 369FF, 001 THRU 075.

EFFECTIVE 369E, 384 AND SUBS; 369FF, 076 AND SUBS;

500N, 001 AND SUBS.

NOT USED ON 369E, 384 AND SUBS; 369FF, 076 AND SUBS;

500N, 001 AND SUBS.

G96-1005-1A

Figure 401. Auto Re−ignition System Equipment (Sheet 1 of 3)

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MD Helicopters, Inc.

MAINTENANCE MANUAL

RE-IGN PRST

K104

RE-IGN

RE-IGN PRST

WARNING LT

(NOTE 7)

TEST SWITCH

WARNING LT

(NOTE 5)

120

110

100⁹

ALTITUDE

EDGE-LIGHTED PANEL-TOP VIEW

(NOTE 4)

SWITCH

XDS9

ANTI-COLL

PITOT

HOUSING

START PUMP

HTR

RE IGNTEST

PULL

FOR

AIR

OFF

SCAV

POS

UTIL

OVSPD

FAULT

AIR

LTS

ANTI-ICE

PWR

TEST

OFF

OFF OFF

RE-IGN

SCREEN

TEST SWITCH

ASSEMBLY

CIRCUIT BREAKER

PANEL

PNL LT

CB104

SUPPORT

ENG. OUT

SWITCH S11

CB106

INSTRUMENT PANEL

RE-IGNITION

(NOTE 4)

SWITCH ASSY XDS9

(TYPICAL) (NOTE 6)

RE-IGNITION PANEL

(369D294201-705)

RELAY

K204

RE-IGNITION PANEL

RELAY BRACKET

(369D294201-703)

RELAY

K304

TB501

TB502

MODULE (NO. 20)

INSTRUMENT T-PANEL

CENTER CONSOLE (RIGHT SIDE)

(WITH CENTER CONSOLE)

(NOTES 1, 2)

G96-1005-2

Figure 401. Auto Re−ignition System Equipment (Sheet 2 of 3)

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CSP-HMI-2

MAINTENANCE MANUAL

CIRCUIT BREAKER

PANEL 369H92143

ENG. OUT

PANEL 369D294566

ENG. OUT

CB105

CB106

AUTO

RE-IGN

HEAT

TRIM

ENG

TEST

TRIM

ENG

INST

GYRO

AUTO

COVER EXISTING

MARKINGS WITH

DE-ICE

CYCLIC

START

OUT

N CYCLIC

START

OUT

RE-IGN

GOV

BLACK DECALS

AUTO RE-IGN

CARGO

CIG

XPDR ADF

ICS

VHF

UHF

VHF

ADD AUTO

RE-IGN DECAL

HOOK

LTR

GYROS

INST

LIGHTS

AUTO ATT

DIR

LDG

ANN

CB124

TOW LDG ANN INST

RE-IGN

HOVER PANEL

ANN PANEL

CB104

ANN PANEL

CENTER CONSOLE PANEL

COVER EXISTING MARKINGS

(WITH T-SHAPE INSTRUMENT PANEL)

CB123

WITH BLACK DECALS

K104

TB1001

IGNITER

TB1003

IGNITION

EXCITER

TERMINAL BOARD AND RELAY ASSEMBLY

STATION

WIRE BUNDLE

137.50

TB200

J1201

ENGINE POWER OUT

WIRE

BUNDLE

DIODE ISOLATOR

ASSEMBLY

(CR1, CR2)

OLEO

(NOTES 7, 9)

SUPPORT

P303

FITTING

START RELAY

(K301)

LOWER

RING

SECTION

SP17

SP18

BATTERY COMPARTMENT (NOTE 8)

ENGINE COMPARTMENT

G96-1005-3

Figure 401. Auto Re−ignition System Equipment (Sheet 3 of 3)

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CSP-HMI-2

MAINTENANCE MANUAL

ENGINE IGNITION CONTROL SYSTEM

INSPECTION/CHECK

1. Automatic Re−ignition System Check

NOTE: Conducting test with engine motoring

(with Ground/Air Switch)

will require pushing the RE-IGN P RST in

dicator to reset the system (Refer to appro

369E

384 - 508

priate PFM for in-flight test of system).

369FF

076 - 091

500N

001 - 044

A. Normal Start

NOTE: Helicopters equipped with the ground/

Verify system operation of normal starting

air switch can be modified to eliminate the

circuit by performing a normal start as

switch (Ref. Sec. 96-10-00, Generator Con

described in appropriate Pilot's Flight Manual.

trol Unit Upgrade to Eliminate Squat

Switch).

2. Automatic Re−ignition System Check

(without Ground/Air Switch)

(1). The RE-IGN TEST switch (S11)

provides for an OFF and two test

369E

509 & subs

positions; GND (up) and FLT (center).

369FF

092 & subs

500N

045 & subs

(2). Both horn and audible warnings are

Verify system operation of automatic re-igni

disabled by ground/air switch (S522)

tion circuit as follows:

when the helicopter is on the ground,

except when RE-IGN TEST switch is

(1). Set BATTERY/OFF/EXT PWR (master)

placed in the GND position.

switch to OFF.

(3). The FLT position provides a complete

(2). Connect external 28 Vdc power.

in-flight systems test by simulating a

fault of the N₁ input to the EPO.

(3). Set master switch to EXT PWR.

(4). Both on-ground and in-flight tests can

(4). Close ENG OUT circuit breaker.

be accomplished by selecting GND

position.

NOTE: Closing ENG OUT circuit breaker pro

vides power at re-ignition relay K104.

(5). On-ground test requires RE-IGN

TEST switch in the GND position.

(5). Set RE-IGN TEST switch to ON.

(a). With power applied, the ENG OUT

(6). Verify audible spark across engine

indicator should be flashing.

igniter gap.

(b). Press the press-to-test button and

(7). Verify Re-ignition indicator lights.

all warning lights should illuminate

momentarily.

(8). Set RE-IGN TEST switch to OFF.

(c). Set RE-IGN TEST switch to GND.

(9). Press Re-ignition indicator. Verify

indicator lamps go out.

(d). Verify horn, audio warning, RE-IGN

P RST indicator is illuminated and

(10). Open ENG OUT circuit breaker.

engine igniter firing.

(11). Set master switch to OFF.

(e). Return switch to OFF, the system

should reset.

(12). Disconnect external power.

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CSP-HMI-2

MAINTENANCE MANUAL

ENGINE IGNITION CONTROL SYSTEM

REPAIRS

1. Auto Re−ignition System Modification

2. Instrument Panel Modification

(Ref. Figure 801)

This section provides for modification instruc

tions of the 369H900118-513 and -515 engine

automatic re-ignition equipment (369D

Consumable Materials

helicopters S/N 003 - 949 only). These

(Ref. Section 91−00−00)

instructions cover relocation of re-ignition

Item

Nomenclature

controls on the instrument panel and neces

CM302

Epoxy primer / Catalyst reducer

sary rewiring to provide full-time operation of

CM305

Lacquer, acrylic

the system.

A. Preparation for Modification

(1). Fabricate cover, as required, for hole

vacated by switch XDS9.

Preparing for modification of installed engine

automatic re-ignition equipment includes the

(2). Install cover on instrument panel.

following:

(3). Install plug button on instrument

panel.

(1). Place BATTERY-OFF-EXT PWR

(master) switch in OFF position.

(4). Paint out lettering at previous auto

re-ignition switch location with acrylic

(2). Disconnect wires from auto re-ignition

lacquer (CM305).

switches as follows:

(5). Fabricate plate as follows:

(a). Remove J501A20 from circuit break

(a). Make plate from 0.062 inch (1.5748

er (CB106-2) and ARM-OFF switch

mm) thick aluminum alloy sheet as

(S11-1) and discard wire.

shown in Figure 801.

(b). Disconnect J501AE20, J502E20,

(b). Apply one coat primer (CM302) and

J501B20, J502A20 and J502D20 at

dry for 1 to 2 hours.

switch (S11).

(c). Apply topcoat of acrylic lacquer

(c). Remove ARM-OFF switch (S11) from

(CM305) and air dry 4 hours mini

instrument panel.

mum.

(6). Install plate and auto re-ignition

(d). Remove J503D20 and J503EE20

switches (XDS9) and (S11, PN 882GK15

from terminal board (TB502-13A and

- Cutler Hammer or equivalent) at new

13C).

location on instrument panel.

(e). Remove J505A20N and J508A20N

(7). Fabricate and install decal on instru

from stud (E2).

ment panel.

(f). Remove J507AA20 from terminal

3. Electrical System Modification

board (TB502-13E).

(Ref. Figure 802)

(g). Remove E559AC22 from splice

(1). Revise wiring as follows:

(MS25181-1).

(a). Install diode at circuit breaker

(3). Remove relays (K304 and K104) and

CB101.

switch (XDS9). Remove all wires from

relays and switch and retain relays and

(b). Install diodes CR3 and CR4 on

switch for reuse.

switch S11.

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MAINTENANCE MANUAL

(c). Install transzorb CR5 on relay K104.

(e). Reinstall relays K104 and K304 in

original position.

(2). Perform check of modified auto re-igni

(d). Rewire switches (S11 and XDS9) and

tion system (refer to the appropriate

relays (K104 and K304) as shown.

PFM).

369H6416 INSTRUMENT

PANEL ASSEMBLY

COVER (SEE VIEW D-D)

HS1957-2 SCREW NAS620A6L

WASHER MS21043 NUT

(OR EQUIVALENT)

REMOVE AUTO RE-IGN SWITCHES AND

BLACK OUT LETTERING AND COVER UP

HOLES AFTER RELOCATION

SS48152 PLUG BUTTON OR EQUIVALENT

(CARR FASTENER COMPANY)

USE EXISTING HOLE IN PANEL,

USE 6-32 X 0.50 IN. (12.7 MM) LS

369H90118-105 SWITCH ASSEMBLY (RE).

SCREW AND WASHER (4 PLACES)

EXISTING SWITCH MAY BE REWIRED

DRILL0.218-0.221 IN. (5.5372-5.6134 MM) DIA

HOLES IN PANEL TO USE TINNERMAN NUT

``U'' TYPE NC, C42332BE-632 OR TAP DRILL

THREADS FOR 6-32 SCREW (REF)

PLATE

882GK15 SWITCH (CUTLER HAMMER)

INSTALL DECAL (SEE VIEW E-E)

G96-1007-1A

Figure 801. Relocation of Auto Re−ignition Controls (Sheet 1 of 2)

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CSP-HMI-2

MAINTENANCE MANUAL

USE EXISTING CLAMP

1.125 IN.

AND HARDWARE

(2.8575 CM)

0.562 IN.

(14.2748 MM)

1.00 IN. 2.54 CM)

0.125 IN. (3.175 MM)

DIA. HOLE

0.87 IN. (22.098 MM)

MODIFY EXISTING

SUPPORT TO FIT

IF REQUIRED

1.12 IN. (2.8448 CM)

B-B

0.375 IN.

(9.525 MM)

0.500-0.505 IN.

1.44 IN.

(12.7-12.827 MM)

1.76 IN.

(3.6576 CM)

DIA. HOLE

(4.4704 CM)

0.175 IN.

(4.445 MM)

0.32 IN. (8.128 MM)

DIA.

0.30 IN. (7.62 MM)

0.15 IN. (3.81 MM)

0.50 IN.

(12.7 MM)

PRESS TO

1.18 IN.

RESET

(2.9972 CM)

0.59 IN.

0.12 IN.

(14.986 MM)

1.00 IN.

(3.048 MM)

6 POINT GOTHIC

(2.54 CM)

0.12 IN.

LETTERS

(3.048 MM)

1.06 IN.

3.00 IN. (7.62 CM)

(2.6924 CM)

AUTO RE-IGN

12 POINT GOTHIC

0.87 IN. (22.098 MM)

0.130-0.143 IN.

LETTERS

TEST

(3.302-3.6322 MM)

DIA. HOLE

0.50 IN.

0.03 in. (0.762 MM)

OFF

(12.7 MM)

R (TYP 4 PLCS)

0.53 IN.

0.88 IN.

(13.462 MM)

(22.352 MM)

COVER

(FOR 369H6416 INSTRUMENT PANEL)

DECAL

MADE FROM ALUMINUM ALLOY SHEET, 2024-T3, QQ-A-250/5,

MADE FROM 3650 SCOTCH CAL BRAND FILM, BLACK

TEMP T-3 0.03 X 1.062 X 1.187 IN. (0.762 X 26.9748 X 30.1498 MM).

BACKGROUND (COLOR NO. 37038) WITH WHITE

APPLY ONE COAT HMS-15-1082 PRIMER AND DRY FOR 1 TO 2

LETTERS (COLOR NO. 37875) PER FED-STD-595.

HOURS. APPLY TOPCOAT HMS-15-1083 ACRYLIC LACQUER AND

E-E

AIR DRY 4 HOURS MINIMUM.

D-D

G96-1007-2A

Figure 801. Relocation of Auto Re−ignition Controls (Sheet 2 of 2)

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CSP-HMI-2

MAINTENANCE MANUAL

ENGINE IGNITION CONTROL SYSTEM

INITIAL INSTALLATION

1. Auto Re−ignition Initial Installation

D. Diode Isolator Assembly Installation

(Ref. Figure 401, Figure 402 and Figure 403)

Consumable Materials

This section provides instructions for installa

(Ref. Section 91−00−00)

tion of the 369H900118-513 and -515 engine

Item

Nomenclature

automatic re-ignition equipment. These

CM313

Insulation varnish

instructions cover removal or modification of

CM612

Tube, silicone

existing equipment to accommodate re-igni

tion equipment.

CM703

Tie strap

CM808

Lacing cord

NOTE: 369D helicopters S/N 003 - 949 did not

provide full time operation. Refer to Auto

NOTE: When providing ground for electrical

Re-ignition Rework for converting system

components, clean contacting surfaces to

to full time operation.

bare metal per Maintenance of Electrical

Bonding Connections (Ref. Chap. 96). Do

A. Reference Data

not tighten electrical clamps or secure elec

trical wiring to existing harnesses until all

The consumable and expendable materials

electrical wiring and components are in

listed are of a commercial nature that could be

stalled.

procurable locally. Alternate, but equivalent,

items might be available, but consultation

(1).

Remove nut and washer securing

with MDHI Customer Service Department is

forward end of K301 start relay to

recommended.

369A2537 oleo support.

(2).

Clean area for electrical bonding

B. Preparation for Installation

around large hole in bracket and that

portion of K301 start relay bracket

Preparing for installation of engine automatic

exposed by removal of nut and washer

re-ignition equipment includes the following:

in step (1). above.

(1). Place BATTERY-OFF-EXT PWR

(3).

Using nut and washer removed in step

(master) switch in OFF position.

(1). above, install diode isolator assem

bly so that lug type diode connectors

(2). Open engine right access door.

are aft.

(3). Identify all components, including

(4).

Locate wire J503C20 (open end) in

attaching hardware removed to gain

harness running vertically, just forward

access to work areas. Protect compo

of Sta. 135.50 bulkhead and approxi

nents from damage and contamination

mately 6 inches (15.24 cm) aft of diode

until installed.

isolator assembly. Place a 2.50 inch

(6.35 cm) length of silicone tubing

C. Automatic Re−ignition System

(CM612) on wire for use in step (6).

Installation

below.

(5).

Connect wire J503B20 from diode CR1

NOTE: The engine automatic re-ignition kits

of diode isolator assembly to the B-end

are supplied with as many parts assembled

of knife splice SPl8. Connect A-end of

as practical, however. some parts may re

same splice to wire J503C20 located in

quire assembly at installation. The follow

step (4). above.

ing procedures provide complete assembly

instructions. The operator should omit those

(6).

Slide silicone tubing over SPl8 splice

steps which may have already been accom

and secure with tie-strap (CM703) at

plished.

each end of splice.

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MAINTENANCE MANUAL

(7).

Remove existing wire K502D20 from

(5). On left side of instrument panel

terminal X2 of K301 start relay. Cut off

structure, install relay K104 in center

existing terminal, remove and save

position and relay K304 in aft position,

existing terminal protector, slip 2.50

on bracket with screws, washers and

inch (6.35 cm) length of silicone tubing

nuts.

on wire, and connect wire to B-end of

NOTE: Bracket is installed in upper half of

knife splice SPl7.

largest lightening hole in left side structure

(8).

Connect A-end of SP17 splice to

of instrument panel.

K502CB20 wire from common connec

(6).

Clean area around ARM-OFF switch

tor 2 of CR1 and CR2 diodes of diode

(S11) mounting hole in lower switch

isolator assembly.

and circuit breaker panel, to prepare

(9).

Slide silicone tubing over splice and

bonding surface for switch support;

secure with tie-strap at each end of

clean all surfaces around holes in

SP17 splice.

support.

(10).

Place terminal protector removed in

(7).

Insert threaded shank of ARM-OFF

step (7). above, on wire K502CA20 of

switch through half-inch (12.7 mm)

diode isolator assembly. Connect wire to

hole in support followed by key washer

X2 terminal of K301 start relay and

with washer tang toward switch

slide terminal protector into place.

actuator arm.

(11).

Secure wiring with lacing cord (CM808)

(8).

Insert ARM-OFF switch through half

as required. making certain that

inch (12.7 mm) mounting hole in lower

sufficient wire slack remains so that

switch and circuit breaker panel; install

connectors are not stressed.

washer and nut making certain tang is

positioned in small hole adjacent to

(12).

After assembly and test apply insula

half-inch (12.7 mm) hole in panel.

tion varnish (CM313) to exposed

threads and tips.

(9).

Clean portion of cylindrical (coil)

housing to contact clamp; insert switch

(13).

Close engine access door.

assembly (XDS9), from front side of

panel. into square cut out mounting

E. Relay and Switch Assembly Installation

hole in lower switch and circuit breaker

panel.

Consumable Materials

(10).

Secure housing of switch (XDS9) to

(Ref. Section 91−00−00)

support with clamp, screw, washers and

Item

Nomenclature

nut.

CM703

Tie strap

CM812

Splice, knife

(11).

Install electrical wiring as follows:

(a). Route wire J502A20 from relay K104

(1). Remove instrument panel left and right

to ARM-OFF switch and connect to

side covers to expose lightening holes.

contact 3 of switch (S11).

(2). Remove ash tray and edge lighted panel

(b). Route wire J503EE20 from relay

from lower switch and circuit breaker

K104 and insert pin in contact C of

panel.

terminal block 502, module 13

(TB502-13).

(3). Remove screws and loosen lower switch

and circuit breaker panel.

(c). Route wire J508A20N from relay

K104 and connect to ground stud E2.

(4). Remove and discard square cutout and

adjacent round hole button covers

(d). Route wire J507AA20 from relay

located above PRESS TO RESET

K104 and insert pin in contact E of

placard.

TB502-13.

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MAINTENANCE MANUAL

(e).

Route wire E559AC22 from relay

(14). Install edge-lighted panel and ash tray

K304 to closest proximity of GEN

on lower switch and circuit breaker

OUT wire E559A22; connect wires

panel.

E559AC22 and E559A22 with splice

(15). Perform Operational Check of engine

(CM812).

automatic re-ignition electrical system.

(f).

Route wire J501AE2O from relay

K304 to contact 1 of ARM-OFF

F. Relay and Switch Assembly Installation

switch (S11); install terminal

(T−Panel with Center Console)

(MS25036-102) on wire J501A20;

connect terminals of wires J501AE20

Consumable Materials

and J501A20 to contact 1 of ARM-

(Ref. Section 91−00−00)

OFF switch (S11). Route wire

Item

Nomenclature

J501A20, install terminal

CM612

Tube, silicone

(MS25036-149) and connect to

CM703

Tie strap

contact 2 of circuit breaker CB106.

CM812

Splice, knife

(g).

Route wire J502E20 from relay, K304

CM815

Solder

and connect to contact 4 of ARM-

OFF switch (S11).

NOTE: T-panels (-703 and -705) with center

(h).

Arrange relay wires to form smooth

console are identical except the -705 is

flow integrating with existing wire

equipped with 14 caution indicators.

bundles; use tie-straps (CM703) as

required to secure wire bundles.

(1). Remove console right side cover.

Ensure sufficient wire slack to avoid

stress on solder joints.

(2). Remove additional panels as required

to facilitate installation of engine

(i).

If bracket has been removed for

automatic re-ignition switches and

installation ease, clean bracket panel

wiring.

contact areas to ensure positive

ground; install bracket with screws

(3). Remove ARM-OFF and RE-IGN

and washers.

ARMED switch hole covers from

instrument panel.

(j).

Route ground wire J505A20N from

switch (XDS9) coil housing and

(4). Locate relay bracket (for relays K104

connect to ground stud E2.

and K304) on right side of console inner

panel.

(k).

Route wire J502D20 from RE-IGN

ARMED switch (XDS9) and connect

(5). Install relays K104 and K304 as

follows:

to contact 6 of ARM-OFF switch

(S11).

(a). Install relay K104 in outboard

(l).

Route wire J503D20 from switch

position, and relay K304 in inboard

(XDS9) and insert pin in contact A of

position on relay bracket, with

TB502-13.

screws, washers and nuts.

(m).

Route wire J501B20 from switch

(b). Arrange relay wires to form a smooth

(XDS9) and insert pin in contact A of

flow, integrating with existing wire

ARM-OFF switch (S11).

bundles; use tie-straps (CM703) as

required to secure wire bundles.

(12). Install instrument panel left side cover.

Ensure sufficient wire slack to avoid

stress on solder joints.

(13). Clean screw attach areas of lower

switch and circuit breaker panel to

(6). Install ARM-OFF switch (S11) and

ensure positive grounding bond; install

RE-IGN/ARMED switch assembly as

panel.

follows:

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MAINTENANCE MANUAL

(a).

Clean area around ARM-OFF (S11)

2). Route wire E559AC22 from relay

switch-hole in instrument panel to

K304 to TB502 and insert pin in

prepare bonding surface for switch

contact C of TB502-20.

(XDS9) support; install AUTO

3). Install pin (MPCM20M-H2) on

RE-IGNITION decal

wire E559AB22; insert pin in

(369H90118-27). Clean all surfaces

contact A of TB502-20 and route

around holes in support.

wire to plug P12. Crimp pin on

(b).

Insert threaded shank of ARM-OFF

opposite end of wire E559AB22

switch (S11) through half-inch

and insert pin in contact D of P12.

mounting hole in support followed by

4). Install pin (MPCM20M-H2) on

key washer with washer tang toward

wire E559AA22; insert pin in

switch actuator arm.

contact B of TB502-20. Route

opposite end of wire E559AA22 to

(c).

Insert ARM-OFF switch (S11)

GEN OUT (XDS18) warning light

through half-inch mounting hole in

and solder (CM815) to contact 3.

instrument panel; install washer and

nut making certain key washer tang

(f). On aircraft equipped with

is in small hole adjacent to half-inch

369D294201-705 instrument panel

(12.7 mm) hole in panel.

face; install wire E559AC22 as

follows:

(d).

Clean portion of cylindrical (coil)

housing to contact clamp; insert

1). Route wire E559AC22 to closest

switch assembly (XDS9) into square

proximity of wire E17A22 (routed

cutout mounting hole in instrument

between P526-EE and P527-A).

panel.

2). Cut wire E17A22; install 2.50 inch

(e).

Secure housing of switch (XDS9) to

(6.35 cm) length of silicone tubing

support with clamp, screw, washers

(CM612) and splice (CM812) wires

and nut.

E559AC22 and E17A22. Slide

tubing over splice and secure with

(7). Install electrical wiring as follows:

tie-straps (CM703).

(a). Route wire J502A20 from relay K104

(g).

Route wire J5017E20 from relay

to ARM-OFF switch (S11) and

K304 and connect to contact 1 of

connect to contact 3 of ARM-OFF

ARM-OFF switch (S11).

switch (S11).

(h).

Route wire J502E20 and connect to

(b). Route wire J503EE20 from relay

contact 4 of ARM-OFF switch (S11).

K104 and insert pin in contact C of

(i).

Route ground wire J505A20N from

terminal block 502, module 13

switch (XDS9) and connect terminal

(TB502-13).

to ground stud E31.

(c). Route wire J508A20N from relay

(j).

Route wire J502D20 from switch

K104 and connect to ground stud

(XDS9) and connect terminal to

E31.

contact 6 of ARM-OFF switch (S11).

(d). Route wire J507AA20 and insert pin

(k).

Route wire J503D20 from switch

in contact E of TB502-13.

(XDS9) and insert pin in contact A of

TB502-13.

(e). On aircraft equipped with

369D294201-703 instrument panel

(l).

Route wire J501B20 from switch

face, install wire E559AC22 as

(XDS9) and connect to contact 3 of

follows:

ARM-OFF switch (S11).

1). Install module No. 20 on TB502.

(m).

Relocate wire J501A20 as follows:

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MAINTENANCE MANUAL

1). On aircraft equipped with 369D

(9). Install console right cover.

294201-703 instrument panel face,

disconnect wire J501A20 from

(10). Secure all panels loosened or removed

CB124 on circuit breaker panel,

for access.

and connect to contact 2 of CB106.

(11). Perform Operational Check of engine

2). On aircraft equipped with 369D

automatic re-ignition system (refer to

294201-705 instrument panel face,

appropriate PFM).

disconnect wire J501A20 from

CB119 on circuit breaker panel,

G. Weight and Balance

and connect to contact 2 of CB105.

(8). Install black cover decals

Weight and balance changes resulting from

(369H90118-35 and -37) over AUTO

installation of engine automatic re-ignition

RE-IGN markings of previously used

equipment are listed in Table 901. After

circuit breaker position on edge lighted

installation of the engine automatic re-igni

circuit breaker panel; install new

tion system equipment, incorporate changes in

AUTO RE-IGN decal (369H90118-33).

helicopter weight and balance record.

Table 901. Weight and Balance Data

Weight

Arm

Moment

Pounds (kg)

inches (cm)

in.−lb

(kg cm)

Added

1.5

(0.6803884)

91.5

(232.41)

1.4

(16.12968)

Removed

0.0

Change

1.5

(0.6803884)

91.5

(232.41)

1.4

(16.12968)

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CSP-HMI-2

MAINTENANCE MANUAL

ENGINE COOLING SYSTEM

MAINTENANCE PRACTICES

1. Engine Cooling System Description and

3. Engine Cooling System Repair and

Operation

Replacement

(Ref. Figure 201 and Figure 202) Helicopter

(Ref. Figure 201 and Figure 202)

engine and transmission oil cooler blower air is

used to cool engine exterior surfaces. After

passing through the oil coolers, the relatively

Consumable Materials

temperate air is redirected by a system of

(Ref. Section 91−00−00)

supports, clamps, and ducts onto the ignition

Item

Nomenclature

exciter, engine gearcase, and compressor and

CM107

Fluorocarbon release agent

turbine section external surfaces. Exhaust air

is discharged overboard through a gap

CM712

Tape, pressure sensitive

between the engine exhaust pipe and engine

access doors.

(1). Unclamp and remove ducts.

2. Engine Cooling System Inspection

(Ref. Figure 201 and Figure 202)

(2). Patch duct damage with tape (CM712).

(1). Inspect ducts for holes, tears, cracks,

NOTE: Apply dry film lubricant (CM107) to

fraying and security. Repair duct

duct and seal mating surfaces prior to as

damage as required.

sembly.

(2). Inspect duct supports and clamps for

condition and security. Repair support

(3). Assemble duct, seals, clamps and

system as required.

attaching hardware.

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MAINTENANCE MANUAL

CONNECTOR

CLAMP

HOISTING

SUPPORT

EYE FITTING

BRACKET

DUCT CONNECTION

POWER TURBINE

COOLING DUCT

COMPRESSOR

COOLING DUCT

9/32 INCH (7.14 MM)

OVERHEAD DUCT SUPPORT

SPACER

50°±10°

1/4 INCH (6.35 MM)

SPACER

CLAMP

COOLING

DUCT

DUCT SUPPORT

RING

SEAL

CLAMP

COOLING DUCT ATTACHMENT

GEARCASE COOLING DUCT ATTACHMENT

CLIP

LOWER TRANSMISSION

OIL COOLER DUCT

STA. 124.00 LOWER

CLAMP

SECTION FRAME

(NOTE)

CLAMP

(NOTE)

ENGINE MOUNT

CLAMP

GEARCASE COOLING DUCT SUPPORT

NOTE:

INSTALL CHAFFING STRIP TO INSIDE SURFACE

OF CLAMP PRIOR TO INSTALLATION

G71-6000-2B

Figure 201. Engine Air Cooling System − 250−C20B and 250−C20R/2 (Sheet 2 of 2)

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MAINTENANCE MANUAL

CLAMP

HOISTING EYE

FITTING

COOLING

DUCT

SEAL

BRACKET

COOLING DUCT ATTACHMENT

CLAMP

(NOTE)

COMPRESSOR COOLING

DUCT INSTALLATION

9/32 INCH (7.14 MM)

50°±10°

SPACER

1/4 INCH (6.35 MM)

SPACER

CONNECTOR

CLAMP

DUCT SUPPORT

RING

CLAMP

DUCT CONNECTION

GEARCASE COOLING DUCT ATTACHMENT

CLIP

LOWER TRANSMISSION

STA. 124.00 LOWER

OIL COOLER DUCT

SECTION FRAME

CLAMP

(NOTE)

CLAMP

(NOTE)

ENGINE MOUNT

GEARCASE COOLING DUCT SUPPORT

CLAMP

CLIP

GEARCASE COOLING DUCT SUPPORT

NOTE:

INSTALL CHAFFING STRIP TO INSIDE SURFACE

OF CLAMP PRIOR TO INSTALLATION

G71-6001-2B

Figure 202. Engine Air Cooling System − 250−C30 and 250−C47 (Sheet 2 of 2)

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MAINTENANCE MANUAL

TABLE OF CONTENTS

Para/Figure/Table

Title

Page

75-10-00 Engine Anti-Icing System (250-C20B, 250-C20R/2, 250-C30

and 250-C47)

Maintenance Practices

201

1. Engine Anti-Icing System Description and Operation

201

2. Engine Anti-Icing System Fault Isolation

201

Table 201. 250-C20B Engine Anti-icing System Fault Isolation

201

Table 202. 250-C20/R2, 250-C30 and 250-C47 Engine Anti-icing System

Fault Isolation

202

250-C20B Engine Anti-Icing Valve Control Cable Replacement

202

A. 250-C20B Engine Anti-Icing Valve Control Cable Removal

202

B. 250-C20B Engine Anti-Icing Valve Control Cable Installation

202

Figure 201. 250-C20/R2, 250-C30 and 250-C47 Engine Anti-Icing

System Wiring

203

250-C20/R2, 250-C30 and 250-C47 Engine Anti-Icing System Controls

Replacement

203

250-C20B Engine Anti-Icing System Inspection

203

250-C20/R2, 250-C30 and 250-C47 Engine Anti-Icing System Inspection

204

250-C20B Engine Anti-Icing System Test

204

250-C20/R2, 250-C30 and 250-C47 Engines Anti-Icing System Test

204

250-C20B Engine Anti-Icing System Control Cable Repair

204

10. 250-C20/R2, 250-C30 and 250-C47 Engine Anti-Icing Valve Repair

204

Figure 202. 250-C20B Engine Anti-Icing System

205

Figure 203. 250-C20/R2, 250-C30 and 250-C47 Engine Anti-Icing

Control Valve

206

Page i

75 Contents

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HANDBOOK OF MAINTENANCE INSTRUCTIONS FOR MDHI 369D/E/FF-500/600N HELICOPTERS (ISSUED: 1990) - page 29