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

MD Helicopters, Inc.

CSP-HMI-2

MAINTENANCE MANUAL

(a).

Remove bolts from inboard side of aft

(2). Install edgelighted and circuit breaker

abrasion strip (369H6102), and aft

panels as applicable (Ref. Chap. 96).

bolt from inboard side of forward

abrasion strip (369H6102), on left

(3). Install crew compartment left or right

landing gear skid.

bulkhead panel and lower portion of left

or right upper side panel as applicable.

(b).

Install screw (NAS603-8) in forward

attach hole of aft abrasion strip

(4). Install crew compartment lower aft

(369H6102).

trim panels (left and right).

(c).

Position chafing bar on inboard side

(5). Install left (outboard) collective stick

of left skid with bent end of bar aft,

cover.

and 3/8 inch (9.525 mm) recess hole

in chafing bar over aft abrasion strip

(6). Install seats and back cushions.

forward attach screw.

(7). In passenger/cargo compartment,

(d).

Align chafing bar aft screwhole with

install fuel cell forward vent in control

aft abrasion strip aft attach hole;

tunnel (Ref. Sec. 28-00-00).

install screw (NAS603-8) to secure

aft portion of chafing bar.

(8). In passenger/cargo compartment,

(e).

Hold chafing bar against skid; locate

install controls access door and foot

bar forward screw hole over forward

support fairings.

abrasion strip aft attach hole; drill

NOTE: The forward bulkhead, Sta. 78.50, trim

0.190-0.200 inch (4.826-5.08 mm)

panel is not installed during use of the hoist

screw hole through chafing bar.

system door retainer equipment.

(f).

Install screw (NAS603-8) to secure

forward end of chafing bar.

(9). Install battery.

Helicopter Equipment Installation

(10). Perform operational check of hoist

system (Ref. Hoist System Operational

Install equipment and panels as follows:

Check).

Remove all tools and foreign

CAUTION

J. Weight and Balance Data

materials from helicopter before

panel installations.

(Ref. After installation of the hoist system,

(1). Prior to closing access areas, check

incorporate changes in the helicopter weight

integrity of entire hoist system installa

and balance records as instructed (Ref. Sec.

tion.

08-10-00).

Table 901. Weight and Balance Data

Weight

Arm

Moment

Configuration

Pounds (kg)

inches (cm)

in−lb (kg cm)

369H90070−521

+42.3

(+19.187)

+98.0

(+248.92)

+4145

(+4775.5)

(R/H Command)

369H90070−522

+39.3

(+17.826)

+98.7

(+250.70)

+3879

(+4469.1)

(L/H Command)

Page 909

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Revision 23

CSP-HMI-2

MD Helicopters, Inc.

MAINTENANCE MANUAL

WHEEL FITTING

LANDING GEAR SKID

REMOVE EXISTING RIVETS

(INBOARD SIDE)

(2 PLCS), INSTALL FLUSH

RIVETS

CABLE ANTI-SNAG PROVISIONS

(ROTATED)

AFT ABRASION

FORWARD ABRASION

STRIP

LEFT SKID (IN

BOARD SIDE)

CHAFING BAR

LEFT LANDING GEAR SKID CHAFING BAR PROVISION

(RH COMMAND HELICOPTERS WITH

CENTER ELECTRICAL CONSOLE ONLY)

STA.

96.92

85.69

1.12 IN.

INSTALL RIVETS

JACK FITTING

1.12 IN.

(2.8448 CM)

(2 PLCS)

0.47 IN.

(2.8448 CM)

(11.938 MM)

16.03 IN.

11.20 IN.

(40.7162 CM)

(28.448 CM)

STA.

112.92

DOOR SILL ANTI-CHAFING BAR PROVISIONS

G25-6008A

Figure 903. Cable Antichafing Bar Installation

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MD Helicopters, Inc.

CSP-HMI-2

MAINTENANCE MANUAL

TABLE OF CONTENTS

Para/Figure/Table

Title

Page

26-10-00 Engine Fire Detection System

Maintenance Practices

201

1. Fire Detector System Description and Operation

201

2. Fire Detector System Troubleshooting

201

3. Fire Detection System Replacement

201

A. Fire Detection System Removal

201

B. Fire Detection System Installation

201

Figure 201. Fire Detection System Interconnect Data

202

Figure 202. Fire Detection System Installation

203

26-20-00 Fire Extinguisher

Maintenance Practices

201

1. Fire Extinguisher Description

201

2. Fire Extinguisher Operation

201

3. Fire Extinguisher Servicing/Inspection

201

Figure 201. Fire Extinguisher Installation (R/H Command)

202

Page i

26 Contents

Revision 23

MD Helicopters, Inc.

CSP-HMI-2

MAINTENANCE MANUAL

FIRE DETECTION SYSTEM

MAINTENANCE PRACTICES

1. Fire Detector System Description and

3. Fire Detection System Replacement

Operation

(Ref. Figure 202)

The fire detection system is located in the aft

section of the fuselage encircling the engine

A. Fire Detection System Removal

bay area. The fire detector cable is looped

around the inboard structure of the engine

(1). Disconnect wire harness from fire

compartment. The fire detection system is held

detector unit.

in place by stainless steel positive locking

(2). Remove hardware securing clamps from

cable clips and clamps attached to the air

cable and fire detector unit.

frame.

The detector consists of a pressure switch

(3). Disconnect fire detection cable quick

connected to a small diameter tube. Inside the

release clips.

tube is helium gas and a core material that

(4). Careful remove fire detection cable

contains trapped hydrogen. The detector can

from engine compartment.

provide an output signal when heat is applied

to it in two ways. If the detector tube average

(5). Replace any broken quick release clips.

temperature exceeds a preset amount, the

helium gas pressure increase will trigger the

B. Fire Detection System Installation

output signal. If there is a local hot spot on the

detector tube, the core will outgas hydrogen.

NOTE:

The release of hydrogen gas will cause a

D Replace any damaged or broken quick re

pressure increase inside the tube, triggering

lease clips.

the output signal. Both of these processes are

reversible. When the tube cools, the output

D Do not exceed minimum bend radius

signal ceases, the hydrogen is readsorbed into

0.375 inch (9.53 mm) when installing fire

the core, and the system is reset. The detector

detection cable.

core has a spiral groove cut into its outside

diameter, so that crushing, flattening, or

(1). Form fire detection cable to fit original

kinking of the detector tube will not prevent

mounting locations.

gas pressure from reaching the pressure

(2). Secure fire detector cable in quick

switch. Loss of tube integrity through cracking

release clips.

or breakage will make the detector inopera

tive, but the detector incorporates a built in

(3). Install clamps to fire detector unit

test for tube integrity.

using previously removed hardware.

2. Fire Detector System Troubleshooting

(4). Attach electrical connector to fire

(Ref. Figure 201)

detection cable connector.

Page 201

26-10-00

Revision 23

MD Helicopters, Inc.

CSP-HMI-2

MAINTENANCE MANUAL

FIRE EXTINGUISHER

MAINTENANCE PRACTICES

1. Fire Extinguisher Description

(2). Remove fire extinguisher from mount

ing bracket.

(Ref. Figure 201) The early model helicopters

(3). Remove safety pin from handle. Point

use the pressurized, dry chemical type of fire

nozzle toward base of flame and

extinguisher. The current models use a

squeeze the handle.

liquified gas which discharges as a vapor at

high nozzle velocity (Halon 1211). The L/H and

3. Fire Extinguisher Servicing/Inspection

R/H command fire extinguishers mount on the

forward door frame between the crew door and

The fire extinguishers are equipped with a

the canopy. The fire extinguisher quickly

pressure gage that indicates normal, charge,

detaches from the mounting bracket by

and overcharge pressures.

unfastening the quick-release clasps. Note the

(1). Dry chemical type - white area indi

current fire extinguishers are equipped with

cates normal operating range of 150 psi

two straps for extra high vibration applica

(1034 kPa). Red area indicates

tions.

CHARGE or OVERCHARGE.

(2). Halon type - green area indicates

2. Fire Extinguisher Operation

normal operating range of 125 psi (862

kPa). Red area indicates CHARGE or

(1). Grasp fire extinguisher handle with one

OVERCHARGE.

hand. Use the thumb and forefinger of

the other hand to unfasten the quick-

Service the fire extinguishers in accordance

release clasp.

with manufacturer's instructions.

Page 201

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Revision 23

MD Helicopters, Inc.

CSP−HMI−2

MAINTENANCE MANUAL

TABLE OF CONTENTS

Para/Figure/Table

Title

Page

28-00-00 Fuel System (369D/E/FF - 500N)

Description and Operation

1. Engine Fuel System

2. Fuel Cells

3. Fuel Quantity System

4. Vent System

5. Fuel Shutoff Valve Control

6. Fuel Shutoff Valve

7. Start Pump

8. Fuel Filter Caution Light Pressure Switch

9. Drain System and Drain Valves

10. Fuel Supply Lines

Fault Isolation

101

1. Fuel System Fault Isolation

101

Table 101. Fuel Supply System Fault Isolation

101

Figure 101. Fuel System Wiring Diagram (Model 250-C20B/R2 Engines)

103

Figure 102. Fuel Quantity System Wiring Diagram

103

Figure 103. Fuel System Schematic

104

Maintenance Practices

201

1. Fuel Cell Cleaning - General

201

2. Uniroyal Fuel Cell Cleaning

201

3. Engineered Fabrics Corp. Fuel Cell Cleaning

201

4. Fuel Cell Handling, Storage and Shipping

201

5. Fuel Cell Preservation and Storage (Uniroyal Cells)

201

6. Fuel Cell Preservation and Storage (Engineered Fabrics Corp. Cells)

201

7. Fuel System Air Bleed (Model 250-C30 Engine Installation)

202

8. Fuel System Air Bleed (Model 250-C20B/R2 Engine Installation)

202

Removal/Installation

401

1. Fuel Shutoff Valve Control Cable Replacement

401

A. Fuel Shutoff Valve Control Cable Removal

401

B. Fuel Shutoff Valve Control Cable Installation

401

Figure 401. Fuel Shutoff Valve Cable Installation

402

2. Fuel Shutoff Valve Replacement

403

A. Fuel Shutoff Valve Removal

403

B. Fuel Shutoff Valve Installation

403

Figure 402. Left Fuel Cell Cover Installation

404

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28 Contents

Revision 19

CSP−HMI−2

MD Helicopters, Inc.

MAINTENANCE MANUAL

TABLE OF CONTENTS (Cont.)

Para/Figure/Table

Title

Page

Fuel Tank Vent System Component Replacement

405

A. Vent Tube/Emergency Valve Assembly Removal

405

B. Forward Vent Crossover Fitting Removal

405

C. Aft Vent Crossover Fitting Removal

405

Figure 403. Vent System (Sheet 1 of 2)

406

D. Fuel Tank Vent System Installation

407

E. Vent Tube/Emergency Valve Assembly Installation

408

Fuel Supply Lines Replacement

409

A. Fuel Supply Lines Removal

409

B. Fuel Supply Lines Installation

409

Start Pump Replacement (Model 250-C20B/R2 / 250-C30 Engine Installation)

409

A. Start Pump Removal

409

Table 401. Fuel Line Torque Values

410

B. Start Pump Installation

410

Figure 404. Start Pump and Fuel Lines Installation (Sheet 1 of 4)

411

Fuel Quantity Transmitter Replacement

415

A. Fuel Quantity Transmitter Removal

415

B. Fuel Quantity Transmitter Installation

415

Fuel System Drain Valve Replacement

415

A. Fuel System Drain Valve Removal

415

B. Fuel System Drain Valve Installation

416

Fuel Cell Replacement

416

A. Fuel Cell Removal

416

B. Fuel Cell Installation

418

C. Fuel Cell Cover Installation

419

Figure 405. Fuel Cells

420

Figure 406. Fuel Cell Support Lacing

421

Adjustment/Test

501

1. Fuel Level Low Caution Light System Test

501

2. Fuel Quantity Transmitter Calibration and Adjustment

501

Figure 501. Fuel Quantity Transmitter Calibration (Sheet 1 of 2)

502

A. Fuel Level Calibration

503

B. Fuel Level Low Warning Light Calibration

503

3. Fuel Quantity Transmitter Functional Check

504

4. Fuel Filter (Bypass) Caution Light Pressure Switch Test

506

Figure 502. Fuel Filter Caution Light Pressure Switch Test

(C20/C30 Engines)

508

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Revision 44

28 Contents

MD Helicopters, Inc.

CSP−HMI−2

MAINTENANCE MANUAL

TABLE OF CONTENTS (Cont.)

Para/Figure/Table

Title

Page

Figure 503. Fuel Filter Caution Light Pressure Switch (C30 Engine)

509

Figure 504. Fuel Filter Caution Light Pressure Switch (C20 Engines)

509

Figure 505. Fuel Filter Caution Light Pressure Switch (C20R/2 Engines

with CECO Pump)

510

Inspection/Check

601

1. Fuel System General Inspection

601

2. Fuel Shutoff Valve Control Cable Swage Test (369D/E)

601

Figure 601. Fuel Shut-Off Control Cable, PN 369A8137-503 Pull Test

602

3. Fuel Shutoff Valve Inspection

603

4. Fuel Quantity Transmitter Inspection

603

5. Tank Vent System Inspection

604

6. Fuel System Vacuum Leak Inspection

604

7. Start Pump Operational Check (Model 250-C20 Series Engines

or 250-C30 Engine With Optional Maintenance Fuel Pump)

605

8. Drain Valve Inspection

605

9. Fuel Cell Inspection

606

10. Fuel Cell Leak Inspection

606

A. Soap Bubble Leak Test Procedures

606

B. Phenolphthalein Stain Inspection Procedures

607

C. Liquid Stand Inspection

607

11. Fuel Tank Pressure Leak Test

608

Repairs

801

1. Fuel Shutoff Valve Control Cable Repair

801

2. Fuel Shutoff Valve Repair

801

3. Fuel Cell Repair

801

4. Uniroyal Self-Sealing and Non-Self-Sealing Cell Repairs

801

A. Scuff Mark Repair

802

B. Reinforcements, Hangers and Splice Repairs

802

C. Loose Patch Repair

802

D. Patch Installation

802

E. Loose Edge and Lap Seam Repairs

804

F. Blister Repair

805

5. Fuel Quantity Transmitter Repair

806

A. Resistor installation, Transmitters PN 369D296303, 369D296303-701 and

369A4245

806

B. MIL-S-8802 Application

807

Page iii

28 Contents

TR13−001

CSP−HMI−2

MD Helicopters, Inc.

MAINTENANCE MANUAL

TABLE OF CONTENTS (Cont.)

Para/Figure/Table

Title

Page

28-00-60 Fuel System (600N)

Description and Operation

1. Engine Fuel System

2. Fuel Cells

3. Fuel Distribution

4. Fuel Vent System

5. Fuel Quantity System

6. Fuel Shutoff Valve Control

7. Fuel Shutoff Valve

8. Fuel Filter Caution Light Pressure Switch

9. Drain System and Drain Valves

10. Fuel Supply Lines

Fault Isolation

101

1. Fuel System Fault Isolation

101

Table 101. Fuel Supply System Fault Isolation

101

Table 102. Fuel Quantity System Wire Data List

103

Figure 101. Fuel Quantity System Wiring Diagram

103

Maintenance Practices

201

1. Fuel Cell Cleaning - General

201

2. Engineered Fabrics Corp. Fuel Cell Cleaning

201

3. Fuel Cell Handling, Storage and Shipping

201

4. Fuel Cell Preservation and Storage (Engineered Fabrics Corp. Cells)

201

5. Fuel System Air Bleed (Model 250-C47 Engine Installation)

201

Figure 201. Field Fabricated Fuel System Bleeding Tool

202

Removal/Installation

401

1. Fuel Shutoff Valve Control Cable Replacement

401

A. Fuel Shutoff Valve Control Cable Removal

401

B. Fuel Shutoff Valve Control Cable Installation

401

Figure 401. Fuel Shutoff Valve Cable Installation

402

2. Fuel Shutoff Valve Replacement

403

A. Fuel Shutoff Valve Removal

403

B. Fuel Shutoff Valve Installation

403

Figure 402. Fuel Shutoff Valve and Fuel Cell Cover Installation

404

Page iv

Revision 44

28 Contents

MD Helicopters, Inc.

CSP−HMI−2

MAINTENANCE MANUAL

TABLE OF CONTENTS (Cont.)

Para/Figure/Table

Title

Page

Fuel Cell Cover Replacement

405

A. Fuel Cell Cover Removal

405

B. Fuel Cell Cover Installation

406

Fuel Supply Lines Replacement

407

A. Fuel Supply Lines Removal

407

B. Fuel Supply Lines Installation

407

Figure 403. Fuel Lines Installation

408

Figure 404. Ejector Pump and Fuel Lines Installation

409

Fuel Cell Vent System Components Replacement

410

A. Fuel Cell Vent System Components Removal

410

B. Fuel Cell Vent System Components Installation

410

Figure 405. Fuel Cell Vent System Components

411

Fuel Cell Replacement

412

A. Fuel Cell Removal

412

B. Fuel Cell Installation

414

Figure 406. Fuel Cell Interconnect and Support Lacing (Sheet 1 of 3)

416

Fuel Filler Neck Gravity Fill Port Replacement

419

A. Fuel Filler Neck Gravity Fill Port Removal

419

B. Fuel Filler Neck Gravity Fill Port Installation

419

Fuel System Drain Valve Replacement

419

A. Fuel System Drain Valve Removal

419

B. Fuel System Drain Valve Installation

419

Fuel Quantity Probe Replacement

420

A. Forward Fuel Quantity Probe Removal

420

B. Forward Fuel Quantity Probe Installation

420

C. Aft Fuel Quantity Probe Removal

420

Figure 407. Fuel Quantity Probes (Sheet 1 of 2)

421

D. Aft Fuel Quantity Probe Installation

422

Adjustment/Test

501

1. Fuel Level Low Light/Fuel Quantity Indicator System Test and Calibration

501

2. Fuel Filter (Bypass) Caution Light Pressure Switch Test

502

Figure 501. Fuel Filter Caution Light Pressure Switch Test Apparatus

(C47 Engine)

503

Inspection/Check

601

1. Fuel System General Inspection

601

2. Fuel Shutoff Valve Inspection

601

3. Tank Vent System Inspection

602

Page v

28 Contents

Revision 44

CSP−HMI−2

MD Helicopters, Inc.

MAINTENANCE MANUAL

TABLE OF CONTENTS (Cont.)

Para/Figure/Table

Title

Page

4. Fuel Quantity Probe Inspection

602

5. Fuel System Vacuum Leak Inspection

602

Figure 601. Fuel System Vacuum Leak Inspection

603

6. Drain Valve Inspection

603

7. Fuel Cell Inspection

604

8. Fuel Cell Leak Inspection

604

A. Soap Bubble Leak Test Procedures

604

B. Phenolphthalein Stain Inspection Procedures

605

C. Liquid Stand Inspection

605

9. Fuel Tank Pressure Leak Test

605

10. Fuel Transfer System Functional Check

606

Figure 602. Fuel Transfer System Functional Check

606

A. Test Setup

607

Figure 603. Fuel Transfer Test Setup

607

B. Check Procedures

608

Repairs

801

1. Fuel Shutoff Valve Control Cable Repair

801

2. Fuel Cell Repair

801

3. Scuff Mark Repair

801

4. Reinforcements, Hangers and Splice Repairs

801

5. Loose Patch Repair

802

6. Patch Installation

802

7. Loose Edge and Lap Seam Repairs

803

8. Blister Repair

804

28-25-00 Anti-Ice / Airframe Fuel Filter (369D/E - 500/600N)

Description and Operation

Table 1. Anti-Ice/Airframe Fuel Filter Effectivity

1. Description

2. Operation

Fault Isolation

101

1. Anti-Ice Fuel Filter System Fault Isolation

101

Table 101. Anti-Ice Fuel Filter System Fault Isolation

101

Page vi

Revision 44

28 Contents

MD Helicopters, Inc.

CSP−HMI−2

MAINTENANCE MANUAL

TABLE OF CONTENTS (Cont.)

Para/Figure/Table

Title

Page

Maintenance Practices

201

1. Anti-Ice Fuel Filter Replacement

201

A. Anti-Ice Fuel Filter Removal

201

B. Anti-Ice Fuel Filter Installation

201

2. Fuel System Air Bleed

202

Figure 201. Anti-Ice Fuel Filter (Sheet 1 of 3)

203

Inspection/Check

601

1. Anti-Ice Fuel Filter System Inspection

601

2. Anti-Ice Fuel Filter Installation Operational Check: 369H90022-BSC

602

3. Anti-Ice Fuel Filter Installation Operational Check: 369H90022-503, -505

and 600N98110-501

602

4. Fuel System Vacuum Leak Check

602

Table 601. Fuel Supply System Torque Values

603

Figure 601. Anti-Ice Fuel Filter Controls (Sheet 1 of 2)

604

Initial Installation

901

Anti-Ice Fuel Filter Initial Installation

901

A. Preparations for Installation

901

B. Anti-Ice Fuel Filter Control Panel Installation: 369H90022-BSC

901

C. Anti-Ice Fuel Filter Control Panel Installation: 369H90022-503, and -505

901

D. Anti-Ice Fuel Filter Control Panel Installation: 600N98110-501

902

E. Firewall Modifications and Bracket Installation

902

F. Fuel Filter Installation

903

Figure 901. Anti-Ice Fuel Filter Modifications and Installation

(369D/E - 500N) (Sheet 1 of 2)

904

Figure 902. Anti-Ice Fuel Filter Modifications and Installation (600N)

(Sheet 1 of 2)

907

Figure 903. Anti-Ice Fuel Filter Wiring Diagram (369D S/N 0001 - 1204)

(Sheet 1 of 2)

910

Figure 904. Anti-Ice Fuel Filter Wiring Diagram (369D S/N 1205 & Subs

and 369E S/N 001 - 383)

912

Figure 905. Anti-Ice Fuel Filter Wiring Diagram (369E S/N 384 & Subs

and 500N S/N 001 & Subs)

913

Figure 906. Anti-Ice Fuel Filter Wiring Diagram (600N S/N 003 & Subs)

(Sheet 1 of 2)

914

G. Post-Installation Inspection

916

H. Furnishings, Panels and Equipment Installation

916

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28 Contents

Revision 44

MD Helicopters, Inc.

CSP-HMI-2

MAINTENANCE MANUAL

FUEL SYSTEM

DESCRIPTION AND OPERATION

Engine Fuel System

(6). Fuel tank servicing is through the tank

filler neck on the right side of the

(1). Engine fuel system operational infor

fuselage.

mation is provided in the applicable

3. Fuel Quantity System

Allison Engine Operation and Mainte

nance Manuals (Ref. Sec. 01-00-00).

(1).

The fuel quantity system is powered by

24 - 28 Vdc current and consists of a

Fuel Cells

float operated quantity transmitter

mounted on the left fuel cell cover and a

(1).

The MDHS helicopter standard fuel

quantity indicator gauge and FUEL

tank consists of two interconnected

LEVEL LOW caution light on the

non-self-sealing bladder cells having a

instrument console. Early series

total capacity of 64 U.S. gallons (242.3

helicopters incorporate the gauge as

L), with 62 gallons (234.7 L) usable.

part of a three-pack instrument cluster.

Alternate self-sealing cells may be

Current helicopters feature an individ

installed having a capacity of 62 U.S.

ual quantity gauge. The system is

gallons (234.7 L), with 60.7 gallons

protected by the INSTR CLUSTER 5

(229.7 L) usable. Bladder and self

ampere circuit breaker. Power is

sealing fuel cells are supplied by

supplied to the system from the DC bus

Engineered Fabrics Corporation and

through the INSTR CLUSTER circuit

Uniroyal, Inc. (Ref. Sec. 01-00-00).

breaker, CB101. With power on and

approximately 35 or 70 pounds of fuel

(2).

Cells are located in separate fiberglass

remaining, depending on customer

lined bays below the passenger com

requirements, the fuel quantity trans

partment floor. Both cells are supported

mitter float arm contacts a spring wire

by a system of airframe brackets,

that completes a circuit to ground

hangers, grommets and nylon suspen

through a transistor located on a circuit

sion cords.

board inside the transmitter assembly.

The transistor switches on the FUEL

LEVEL LOW caution light. Refueling

(3).

Each fuel cell is equipped with an

raises the float, breaks the transistor

access cover fitting, cover, forward and

circuit and switches off the FUEL

aft vent crossover fittings, fuel intercon

LEVEL LOW caution lamp. The float

nect fittings, internal baffles and baffle

operates a rheostat that controls

support rods.

electrical current through the quantity

indicator circuit. Fuel level changes

(4).

The right fuel cell contains the male

alter transmitter resistance values that

portion of the cell interconnect fitting,

effect the fuel quantity indicator needle

filler neck, cap and attached filler

position.

shield.

Vent System

(5).

The left fuel cell contains the female

half of the cell interconnect fitting,

(1). Tank cells are vented to atmosphere

sump plate, sump/tank drain valve,

through bottom and side fuselage ports

engine start fuel pump (C20 series

by a system of interconnected hoses and

engine installation) or fuel inlet fitting

tubes attached to the forward and aft

(C30 engine installation). The left cell

ends of each fuel cell. A fuel vent

cover supports the fuel quantity

emergency shutoff valve automatically

transmitter, manually actuated fuel

closes to prevent fuel loss through the

shutoff valve, fuel supply tubes, hoses

vent system when a 45° helicopter pitch

and attaching hardware.

or roll angle limit is exceeded.

Page 1

28-00-00

Revision 19

CSP-HMI-2

MD Helicopters, Inc.

MAINTENANCE MANUAL

5. Fuel Shutoff Valve Control

filter pressure AF (after filter) and BF

(before filter) ports just upstream of the

(1). A red fuel shutoff control knob labeled

engine fuel pump. The switch is

FUEL, PULL TO CLOSE is located on

sensitive to a preset differential

the instrument panel face. The flexible

pressure. An increase in BF pressure

cable and housing is routed aft under

with a concurrent decrease in AF

the floor to the shutoff valve lever on

pressure due to partial or complete

the left fuel cell access cover.

filter blockage may intermittently or

completely close the switch depending

6. Fuel Shutoff Valve

on the nature of the filtered material.

Switch contacts complete an electrical

(1). The cable actuated, mechanically

circuit through a case ground that

detented fuel shutoff valve is located on

switches on the FUEL FILTER

the left fuel cell access cover. Valve

caution lamp, a part of the instrument

lever arm travel from full open to closed

console caution and warning light

is 90°.

array.

7. Start Pump

9. Drain System and Drain Valves

NOTE: Helicopters with C30 engines are not

equipped with a start pump. Fuel is drawn

(1). One spring loaded plunger drain valve

from the tank by the engine-driven fuel

is installed in the fuel tank sump plate.

pump.

Air in the fuel system will

(1).

Helicopters with C20 series engines are

WARNING

cause a power reduction or

equipped with a submerged, single

flameout. Do a fuel system vacuum leak

stage centrifugal, 24 - 28 Vdc, 4.5

check and system air bleed after open

ampere, negative ground, electric start

ing fuel system to atmosphere and

pump bolted to the sump plate in the

prior to releasing helicopter for flight.

left fuel cell. Pump delivery volume at

sea level is 300 lbs/hr (136 kg/hr),

NOTE: The tank sump drain valve is installed

nominal at 10 psi (68.95 kPa), mini

in the tank sump mount plate on the bottom

mum. Delivery at 20,000 feet (6100 M)

of the left fuel cell. The valve is accessed

is 120 lbs/hr (54.48 kg/hr), nominal at

from under the helicopter.

11 psi (75.84 kPa), minimum. The start

pump is controlled by a 7.5 ampere

(2). An additional drain valve and asso

circuit breaker/switch on the instru

ciated tubing is installed on helicopters

ment panel.

equipped with an optional anti-ice

(airframe) fuel filter.

(2).

369F - Maintenance Fuel Pump

Helicopters with C30 engines are not

equipped with a start pump. An

10. Fuel Supply Lines

optional maintenance fuel pump with

the same specifications as the C20

(1). The engine fuel supply lines consist of:

series engine submerged start pump

(a). A hose between the start pump (C20

can be installed. The maintenance fuel

engines) or fuel pickup fitting (C30

pump is used to bleed or purge fuel

engines) to the fuel shutoff valve.

lines after maintenance and is not used

during engine operation. The mainte

(b). A tube between the fuel shutoff valve

nance fuel pump is controlled by a 7.5

and firewall fitting.

ampere circuit breaker/switch on the

instrument panel.

(c). A hose from the firewall fitting to the

Fuel Filter Caution Light Pressure Switch

engine filter inlet port.

(1). A differential pressure switch is

(d). Associated elbows, fittings and

installed across the engine fuel pump

unions.

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CSP-HMI-2

MAINTENANCE MANUAL

FUEL SYSTEM

FAULT ISOLATION

1. Fuel System Fault Isolation

Table 101. Fuel Supply System Fault Isolation

Symptom

Probable Trouble

Corrective Action

Start pump supplies

Fuel tank empty.

Refuel helicopter.

insufficient or no fuel to

Defective start pump.

Replace start pump.

engine.

Disconnected or ruptured fuel

Check all fuel lines for security and condition.

line.

Repair or replace parts as required.

Clogged fuel line.

Repair as required.

Clogged fuel cell and start

Clean as required.

pump inlet screens.

Twisted or kinked fuel supply

Repair as required.

hose.

Defective fuel shutoff valve.

Repair or replace fuel shutoff valve.

Fuel shutoff valve control

Repair or replace control cable.

cable failed or disconnected.

FUEL FILTER warning light

Clogged engine fuel filters.

Replace pump and gas producer fuel control

on.

filters. Clean fuel control pneumatic (air)

circuits (refer to Allison Engine Operation and

Maintenance Manual). When installed, replace

anti−ice (airframe) filter. Bench check FUEL

FILTER caution light pressure switch.

Fuel contamination

Inspect and clean the fuel cell and start pump

inlet screens if large amounts of foreign

material are found in the engine driven fuel

pump filter (or the optional airframe fuel filter if

installed).

Defective fuel filter pressure

Replace pressure switch.

switch.

Wiring fault.

Repair wiring.

Engine power surge or

Water/ice in fuel system.

Drain water out of tank and fuel supply system.

flameout with start pump ON

and adequate fuel on board.

Engine power surge or

Water/ice in fuel system.

Same as above.

flameout with start pump OFF.

Air in fuel system.

Bleed fuel system.

Air leaking into system.

Vacuum leak check fuel supply system.

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MAINTENANCE MANUAL

Table 101. Fuel Supply System Fault Isolation

Symptom

Probable Trouble

Corrective Action

Bottom of fuselage stays wet Loose or broken lines or

Inspect and repair as required.

with fuel.

fittings.

Fuel tank leak.

Remove, test and repair, or replace cells.

FUEL LEVEL LOW caution

Transistor current leakage

Install resistor in transmitter circuit.

light stays on, glows or flickers

through FUEL LEVEL LOW

with known quantity above low

caution lamp.

level.

Defective fuel quantity

Remove, test, calibrate and repair or replace

transmitter.

fuel quantity transmitter.

Erroneous fuel quantity gauge Loose or defective wiring or

Inspect wiring and repair.

readings.

connections.

Defective gauge.

Remove, test and replace a defective gauge.

Defective fuel quantity

Remove, test, calibrate and repair or replace

transmitter.

NOTE: 369FF Helicopters are not equipped with a start pump.

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CSP-HMI-2

MAINTENANCE MANUAL

FUEL SYSTEM

MAINTENANCE PRACTICES

Fuel Cell Cleaning − General

4. Fuel Cell Handling, Storage and Shipping

Do not use cell fittings as hand

CAUTION

(1). Fuel cells are susceptible to fungus

holds. Do not store fuel cells un

growth after contact with contaminated

crated or exposed to direct sunlight, ozone,

fuel. Fungus trapped in the fuel filters

dirt, moisture, solvents, chemicals, or ex

indicates fuel tank contamination.

tremes of heat and humidity.

Remove, inspect, clean or replace filter

(1). Store and ship cells in a suitable

elements per applicable Allison Engine

protective container.

Operation and Maintenance Manual.

Where installed, service anti-ice

(a). Apply protective tape over all cell

(airframe) filter (Ref. Sec. 28-25-00).

machined fittings.

(b). Use packing material to keep the cell

(2). Periodic incorporation of an FAA

from shifting in transit.

approved anti-fungal fuel additive will

kill and prevent new fungus growth.

(c). Suspended self-sealing cells to

maintain cell shape.

5. Fuel Cell Preservation and Storage

Uniroyal Fuel Cell Cleaning

(Uniroyal Cells)

Steam cleaning may cause ir

CAUTION

reparable cell damage. Do not

use MEK, soap or commercial cleaning de

D Uniroyal cells removed from service must

tergents to clean rubberized fabric fuel cells.

not be left dry for more than 10 days with

Some cleaning agents leave a residue that

out the application of oil as a plasticizing

will react with fuel to form materials that

agent. The cell liner will loose pliability if

can block fuel filters.

left dry for extended periods and subse

quent flexing may cause the material to

crack.

(1). Clean Uniroyal fuel cell interior/exter

D Do not work on cell in ambient tempera

ior surfaces with lint free cloth moist

tures below 50°F (10°C).

ened with water, alcohol or kerosene.

No other cleaning materials should be

(1). Before removing cell from airframe:

used.

(a). Spray or wipe exposed internal and

external cell surfaces with SAE 10

petroleum based oil.

3. Engineered Fabrics Corp. Fuel Cell

Cleaning

(b). Allow oil to soak into cell for 24 hours

to soften cell material prior to

handling or folding.

Do not steam clean Engineered

CAUTION

Fabrics Corp. fuel cells. Steam

(c). Mop up puddled oil.

cleaning may cause irreparable damage.

6. Fuel Cell Preservation and Storage

(Engineered Fabrics Corp. Cells)

(1). Clean cell exterior and interior surfaces

with warm soapy water and clean lint

NOTE: Engineered Fabrics Corp. VITHANE/R

free cloth. Rinse away all soap residue

fuel cells do not require oiling for preserva

and wipe dry.

tion.

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MAINTENANCE MANUAL

(1). Thoroughly clean cell with warm soapy

NOTE: Check fuel supply system for leakage

water. Wipe completely dry.

with vacuum (Ref. Fuel System Vacuum

Leak Inspection).

Do not work on cell in ambient

CAUTION

temperatures below

70°F

8. Fuel System Air Bleed (Model

(21°C).

250−C20B/R2 Engine Installation)

(a). Fold cell over protective wadding as

Fuel/air vapor discharged

WARNING

loosely as possible and with a mini

during bleeding is a fire haz

mum number of folds.

ard. Prevent fuel vapor accumulation,

ignition and fire. Perform work in an

(b). Wrap the cell in a protective cover.

open, well ventilated area away from

all potential ignition sources. Attach

(c). Put cell in a suitable storage/ship

helicopter to an approved electrical

ping container. Use wadding as

ground. Wear approved eye protection.

required to prevent movement. Do

not stuff cell into an undersized

(1). Bleed air from helicopter fuel systems

container.

as follows:

Do not operate start pump in an

(d). Store cell at 70°F (21°C) away from

CAUTION

empty fuel tank.

sunlight and moisture.

(2). Refuel helicopter as required.

7. Fuel System Air Bleed (Model 250−C30

Engine Installation)

(a). Connect battery.

(b). Open engine access doors.

Fuel/air vapor discharged

WARNING

during bleeding is a fire haz

(c). In crew compartment; push FUEL

ard. Prevent fuel vapor accumulation,

shutoff valve knob in to open shutoff

ignition and fire. Perform work in an

valve.

open, well ventilated area away from

all potential ignition sources. Attach

(d). Set helicopter master switch to

helicopter to an approved electrical

BATTERY.

ground. Wear approved eye protection.

(e). Set START PUMP switch ON to

(1). Helicopters with C30 engines fuel

pressurize fuel system. Check; start

supply systems are not equipped with a

pump is operating.

start pump. However, the helicopter

NOTE: Refer to applicable Allison Engine Op

fuel system has an engine driven self

eration and Maintenance Manual for specif

priming pump that will fill the fuel

ic engine fuel system air bleed information.

system when the engine is motored

with the starter. Motor engine per the

(f). Purge air from engine fuel system

appropriate Pilot's Flight Manual.

per Allison Engine Operation and

Maintenance Manual.

(2). Bleed air out of helicopter engine fuel

controls per Allison Engine Operation

(3). Set START PUMP and battery

and Maintenance Manual.

switches OFF.

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CSP-HMI-2

MAINTENANCE MANUAL

FUEL SYSTEM

REMOVAL/INSTALLATION

1. Fuel Shutoff Valve Control Cable

(1). Thread cable assembly aft through

Replacement

instrument panel or console, lockwash

er, jamnut and grommets to fuel shutoff

A. Fuel Shutoff Valve Control Cable

valve. Maintain a cable bend radius

Removal

greater than 3.5 inches (8.89 cm).

(Ref. Figure 401)

(2). Secure forward end of cable with

lockwasher and jamnut.

(1). Remove left fuel cell floor access panel.

(2). Disconnect control wire from fuel

(3). Slip control cable wire through fuel

shutoff valve swivel.

shutoff valve lever swivel.

(3). Remove control cable ty-raps and

(4). Secure end of cable housing to cell cover

clamps.

with a clamp, washer and screw.

(4). Remove instrument panel left fairing

(5). Install remaining clamps and ty-raps.

and lower cover panels (instrument

panel mounted).

(6). Rig cable with shutoff valve lever hard

against open stop. Adjust cable to get a

(5). Completely back jamnut away from

0.090-0.150 inch (2.286-3.810 mm) gap

cable plunger housing (Ref. Figure 401,

between bottom of control knob and

view A).

cable housing end fitting. Tighten cable

swivel pinch nut. Install cotter pin.

(6). Remove straps securing cable in nose

(instrument panel mounted) or remove

Control action must move valve

clamp in compartment under pilot's

CAUTION

to full open against mechanical

seat (console mounted).

stop without bottoming control knob on

cable housing. Control cable operation shall

NOTE: Attach a trace wire or cord to the valve

be smooth with no binding.

end of the cable before pulling assembly out

of the instrument panel. Trace will guide re

(7). Pull valve control knob out with a

placement cable into correct position.

spring scale. Required valve actuation

force to be not more than 12 pounds

(7). Pull cable assembly out through

(53.38 N).

washer, jamnut and instrument panel.

(8). Repair, adjust or replace valve control

B. Fuel Shutoff Valve Control Cable

system components to meet force limit.

Installation

(Ref. Figure 401)

(9). Reinstall left fuel cell floor access panel.

Pulling detent knob out of cable

(10). Reinstall instrument panel left fairing

CAUTION

housing two or more inches may

and lower cover panels (instrument

result in loss of the detent ball.

panel mounted).

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MAINTENANCE MANUAL

DETENT RELEASE

CABLE PLUNGER

DETENT BALL

PLUNGER HOUSING

0.090-0.150 INCH

PLUNGER HOUSING

SPRING

(2.286-3.810 MM)

INSTRUMENT PANEL

CABLE PLUNGER

INSTRUMENT PANEL

NUT

CABLE RIGGING

HOLE

LOCKWASHER

OPEN

LEVER

CABLE HOUSING

CONTROL KNOB ASSEMBLY

CLOSED

FUEL SHUTOFF VALVE ORIENTATION

AND LEVER POSITIONS

(LOOKING DOWN)

CABLE WIRE

CONSOLE-MOUNTED

END CLAMP

CONTROL

INSTRUMENT

PANEL

GROMMET

FUEL SHUTOFF

CABLE

CLAMP

STRAP

STA. 78.50

NYLON GROMMET

STA. 64.36

STRAP

BRACKET

CREW COMPARTMENT

FLOOR

FUEL SHUTOFF

STRAP

CABLE

STA. 50.50

G28-0001A

Figure 401. Fuel Shutoff Valve Cable Installation

Page 402

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CSP-HMI-2

MAINTENANCE MANUAL

2. Fuel Shutoff Valve Replacement

(5). Unplug fuel quantity transmitter

connector from cell cover receptacle.

A. Fuel Shutoff Valve Removal

(Ref. Figure 402)

(6). Unclamp and disconnect control cable

from fuel shutoff valve.

Avoid fuel vapor ignition

WARNING

and fire. Use only nonspark

(7). Unfasten and remove Sta. 91.00 and

ing tools and explosion proof work

102.00 left fuel cell cover support

lights. Attach helicopter to an ap

brackets.

proved electrical ground. Switch OFF

all electrical power. Disconnect exter

nal power and battery before opening

CAUTION

fuel system. Ensure work area is ade

quately ventilated.

D Do not strain or bend fuel quantity trans

mitter float arm.

CAUTION

D Handle fuel cell cover with care. Prying

cover from cell opening or rough handling

D Air in fuel system may cause power

may damage seal or cell fitting.

surges or flameout. Bleed off trapped air

after opening system at any point be

tween fuel tank and engine fuel nozzle.

(8). Remove fuel quantity transmitter

flange screws. Lift transmitter assem

D Prevent fuel system contamination. In

bly out of cover opening.

stall caps on the ends of hoses, tubes and

fittings as parts are removed. Bag and

(9). Unbolt cell access cover. Prop cover

identify small parts to prevent loss or

open with suitably padded blocks.

damage.

(1). Defuel helicopter. Drain remaining fuel

(10). Using a backup wrench on valve,

from tank sump drain valve into a

separate fuel supply hose from fuel

suitable container.

shutoff valve.

(2). Remove left fuel tank access panel from

(11). Remove fuel shutoff valve and attach

passenger/cargo compartment floor.

ing hardware.

(3). Unclamp fuel supply tube between fuel

shutoff valve and Sta. 124.00 bulkhead

B. Fuel Shutoff Valve Installation

elbow. Using backup wrench on bulk

head elbow so it will not rotate, discon

(Ref. Figure 402)

nect and remove tube.

(4). With 250-C20B/R2 Engine or 250-C30

NOTE: Fuel shutoff valve installation steps are

Engine With Optional Maintenance

given in Fuel Cell Cover Installation proce

Fuel Pump: Unclamp start pump wire

dures.

harness and disconnect plug from cell

cover receptacle.

(Ref. Fuel Cell Cover Installation)

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MD Helicopters, Inc.

MAINTENANCE MANUAL

SCREW, TORQUE; 20-25 IN. LB

(2.26 - 2.82 NM) (TYP)

SETSCREW

CABLE

(NOTE)

WIRE

BOLT, TORQUE; 70-90 IN. LB

VALVE LEVER

(7.91 - 10.17 NM) (TYP)

AND SWIVEL

BUSHING

ELECTRICAL WIRING

HARNESS

ENGINE FEED HOSE

SUPPORT BRACKET (3

SHUTOFF VALVE TO

PLACES)

FIREWALL

TUBE NUT, TORQUE;

230-260 IN. LB (25.99 - 29.38 NM)

CONTROL

CABLE

CARGO

ELECTRICAL CONNECTOR

COMPARTMENT

FLOOR

FUEL SHUTOFF VALVE

SEAL WASHER

JAMNUT, TORQUE; 240-280 IN. LB

(27.12-31.64 NM)

HOSE NUT, TORQUE; 230-260 IN. LB

FUEL QUANTITY

(25.99-29.38 NM)

TRANSMITTER

FUEL INLET HOSE

ELECTRICAL

RECEPTACLE

START PUMP ELECTRICAL

WIRING HARNESS

NOTE:

REQUIRED AT LOCATION SHOWN.

G28-0002A

Figure 402. Left Fuel Cell Cover Installation

Page 404

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CSP-HMI-2

MAINTENANCE MANUAL

3. Fuel Tank Vent System Component

(7). Remove vent tube/emergency valve

Replacement

assembly attaching hardware. Remove

flexible tubing from lower vent tube tee.

Avoid fuel vapor ignition

WARNING

and fire. Use only nonspark

(8). Rotate emergency shutoff valve inboard

ing tools and explosion proof work

and slip assembly down over landing

lights. Attach helicopter to an ap

gear structure. Remove tube assembly

proved electrical ground. Switch OFF

through controls access panel opening.

all electrical power. Disconnect exter

nal power and battery before opening

(9). Unclamp flexible tubing from side vent

fuel system. Ensure work area is ade

fairing. Remove tubing through controls

quately ventilated.

access opening.

Prevent fuel system contamina

B. Forward Vent Crossover Fitting Removal

CAUTION

tion. Install caps on the ends of

(Ref. Figure 403)

hoses, tubes and fittings as parts are re

moved. Bag and identify small parts to pre

(1). Unbolt forward vent crossover fitting

vent loss or damage.

flanges.

(1). Defuel helicopter. Drain remaining fuel

(2). Remove fitting, clamps, seals and

from tank sump drain valve into a

washers.

suitable container.

(3). Cover cell vent fittings and aft vent line

Prevent spontaneous com

WARNING

tube openings.

bustion or explosion. Never

use oxygen to purge or ventilate fuel

C. Aft Vent Crossover Fitting Removal

tank or fuel system components. Fuel,

either vapor or liquid, will violently

(Ref. Figure 403)

react with an oxygen rich atmosphere.

NOTE: Left and right fuel cell access covers

(2). Ventilate fuel tank with an inert gas,

must be removed to get at aft vent crossover

such as nitrogen, or low pressure

U-tube attaching hardware.

compressed air applied through filler

neck.

(1).

Remove left and right fuel cell floor

access panels.

A. Vent Tube/Emergency Valve Assembly

Removal

(2).

Unclamp fuel supply tube between fuel

shutoff valve and Sta. 124.00 bulkhead

(Ref. Figure 403)

elbow. Using backup wrench on bulk

head elbow so it will not rotate, discon

(1). Unbolt and remove right fuel cell access

nect and remove tube.

cover.

(3).

With 250-C20 Series Engines or

(2). Remove right foot support, controls,

250-C30 Engine With Optional Mainte

and fuel vent access panels.

nance Fuel Pump: Unclamp start pump

(3). Remove right seat from crew compart

wire harness and disconnect plug from

ment.

cell cover receptacle.

(4). Move collective pitch stick full down.

(4).

Unplug fuel quantity transmitter

connector from cell cover receptacle.

(5). In passenger/cargo compartment;

remove right and left fuel tank floor

(5).

Unclamp and disconnect control cable

access panels.

from fuel shutoff valve.

(6). Remove lockwire from vent connector

(6).

Unfasten and remove Sta. 91.00 and

hoses and main rotor mast pan drain

102.00 left fuel cell cover support

tube.

brackets.

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MD Helicopters, Inc.

MAINTENANCE MANUAL

PAN

DRAIN TUBE

LOCKWIRE

CLIP

(2 PLACES)

BOLT

WASHER

LACING CORD

(TYPICAL)

WASHER

BOLT

CLAMP

BOLT

WASHER

NUT

FROM AFT VENT

VENT TUBE

SCREW

LOCKWIRE

(TYPICAL)

WASHER

CONNECTOR HOSE

BOLT, TORQUE; 36-46 IN. LB

SIDE VENT FAIRING

(NOTE 2)

(4.06-5.20 NM)

WASHER

CLAMPS

SCREW

SUPPORT COIL

CLIP

WASHER

FUEL VENT

ANTI-SIPHON

COVER

HOLES

INTERCONNECT

FLEXIBLE TUBING

FITTING

(NOTE 1)

SEAL WASHER

STAND-OFF

SEAL WASHER

WASHER (TYP)

LOWER VENT FAIRING

FWD INTERCONNECT AND

NOTES:

EMERGENCY VALVE ASSY

ROUTED THRU LANDING GEAR BRACE.

NOT TO BE PAINTED.

G28-0003-1B

Figure 403. Vent System (Sheet 1 of 2)

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CSP-HMI-2

MAINTENANCE MANUAL

VALVE CLOSED WHEN TILT

EXCEEDS 45° FROM VERTICAL

CLAMP

INTERCONNECT

OVERBOARD

HOSE

VALVE SEAT

SEAL WASHER

VALVE

CELL

TUBE

(REF)

WEIGHT

FUEL VENT

NUT, TORQUE; 40-60 IN. LB

(4.52-6.78 NM)

G28-0003-2B

EMERGENCY VENT

AFT INTERCONNECT

SHUTOFF VALVE

Figure 403. Vent System (Sheet 2 of 2)

(12). Cap tube and cell openings.

CAUTION

(13). Inspect all vent system components

D Do not strain or bend fuel quantity trans

(Ref. Fuel Tank Vent System Inspec

mitter float arm.

tion).

D Do not damage cell cover bonded seal.

D. Fuel Tank Vent System Installation

Handle fuel cell covers with care. Prying

covers from cell openings or rough handl

(Ref. Figure 403)

ing may damage seal or cell fitting.

Consumable Materials

(7). Remove fuel quantity transmitter

(Ref. Section 91−00−00)

flange screws. Lift transmitter assem

Item

Nomenclature

bly out of cover opening.

CM124

Kerosene

(8). Unbolt and prop fuel cell access cover

open with suitably padded blocks.

Avoid fuel vapor ignition

WARNING

and fire. Use only nonspark

(9). Use a backup wrench on valve and

ing tools and explosion proof work

separate fuel supply hose from fuel

lights. Attach helicopter to an ap

shutoff valve. Move fuel cell cover to get

proved electrical ground. Switch OFF

at remaining hardware.

all electrical power. Disconnect exter

nal power and battery before opening

(10). Reach back inside cells and remove

fuel system. Ensure work area is ade

vent interconnect nuts. Separate aft

quately ventilated.

U-tube interconnect from cells.

(1). Wipe forward and aft cell vent

(11). Unclamp and remove hose between

fittings and crossover tube flanges

U-tube interconnect tee and straight

clean with kerosene (CM124) or

tube. Remove U-tube interconnect.

equivalent on a clean shop towel.

Discard sealwashers.

Wipe dry.

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MAINTENANCE MANUAL

NOTE: Do not lubricate fitting sealwashers.

E. Vent Tube/Emergency Valve Assembly

Lubricants may cause seal cold flow and

Installation

subsequent leakage.

(Ref. Figure 403)

(2). Install new sealwashers on aft vent

(1).

Move collective pitch stick full down.

tube ends. Insert tube ends through cell

fittings. Reach inside cell and install

(2).

Remove protective covers from fittings

nuts.

and tubes.

(3). Torque aft vent U-tube interconnect

(3).

Work emergency valve and vent tube

nuts to 40 - 60 inch-pounds (4.52 -

assembly through landing gear brace

6.78 Nm).

then into position in tunnel.

(4). Install hose and clamps between

(4).

Insert vent tube assembly in bottom

interconnect U-tube and straight tube.

vent fairing.

(5). Position new sealwashers on cell

(5).

Loosely install vent tube support

forward vent fittings. Slip vent tube

clamps, washers and bolts.

into cell fitting.

(6).

Install flexible tubing between side vent

NOTE: Permatex Form-A-Gasket No.1 may be

fairing and vent tube assembly tee.

used to hold metal stand-off washers in

place.

(7).

Clamp flex tube ends in position with

two or three wraps of lockwire.

(6). Sandwich one AN960-10 washer on

each side of seal washer between vent

(8).

Tighten vent tube assembly support

tube flanges and cell fittings. Align

clamp and bracket fasteners.

washers with bolt holes. Install bolts

with one washer under each bolt head.

(9).

Install and secure remaining vent

system connector hoses with lockwire.

(7). Torque forward vent interconnect tube

flange bolts to 36 - 46 inch-pounds

(10).

Operate all flight controls through full

(4.07 - 5.20 Nm).

range of motion to ensure no interfer

ence exists between control linkages

(8). Connect powerplant supply tube to Sta.

and vent system. No interference is

124.00 bulkhead elbow. Loosely install

allowed. Adjust vent system hardware

tube support clamps, screws, washers

as required.

and nuts. Using backup wrench on

bulkhead elbow so it will not rotate,

(11).

Install fuel vent access panel.

torque tube nut to 230 - 260 inch-

pounds (25.99 - 29.38 Nm).

(12).

Install controls access and foot support

panels.

(9). Install fuel cell covers (Ref. Fuel Cell

Cover Installation).

(13).

Install crew seat.

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CSP-HMI-2

MAINTENANCE MANUAL

4. Fuel Supply Lines Replacement

(4). Apply a torque alignment stripe to fuel

line tube, hose and fitting fasteners.

A. Fuel Supply Lines Removal

5. Start Pump Replacement (Model

(Ref. Figure 404)

250−C20B/R2 / 250−C30 Engine Installation)

Avoid fuel vapor ignition

WARNING

and fire. Use only nonspark

NOTE: Use these start pump removal and

ing tools and explosion proof work

installation procedures for helicopters with

lights. Attach helicopter to an ap

250-C30 engines equipped with optional

proved electrical ground. Switch OFF

maintenance fuel pump.

all electrical power. Disconnect exter

nal power and battery before opening

A. Start Pump Removal

fuel system. Ensure work area is ade

(Ref. Figure 404)

quately ventilated.

Avoid fuel vapor ignition

CAUTION

WARNING

and fire. Use only nonspark

ing tools and explosion proof work

D Air in fuel system may cause power

lights. Attach helicopter to an ap

surges or flameout. Bleed off trapped air

proved electrical ground. Switch OFF

after opening system at any point be

all electrical power. Disconnect exter

tween fuel tank and engine fuel nozzle.

nal power and battery before opening

D Prevent fuel system contamination. In

fuel system. Ensure work area is ade

stall caps on the ends of hoses, tubes and

quately ventilated.

fittings as parts are removed. Bag and

identify small parts to prevent loss or

Prevent fuel system contamina

CAUTION

damage.

tion. Install caps on the ends of

hoses, tubes and fittings as the parts are re

(1). Defuel helicopter. Drain remaining fuel

moved. Bag and identify small parts to pre

from tank sump drain valve into a

vent loss or damage.

suitable container.

(1).

Defuel helicopter. Drain remaining fuel

(2). Disconnect, remove and cap fittings and

from tank sump drain valve into a

lines as required.

suitable container.

B. Fuel Supply Lines Installation

(2).

Remove left fuel tank access panel from

(Ref. Figure 404)

passenger/cargo compartment floor.

(1). Install and torque engine fuel supply

(3).

Unclamp fuel supply tube between fuel

lines (Ref. Table 401).

shutoff valve and Sta. 124.00 bulkhead

NOTE: It may be necessary to install a peelable

elbow. Using backup wrench on bulk

shim washer between the Sta. 124.00 fire

head elbow so it will not rotate, discon

wall and the bulkhead elbow washer to ob

nect and remove tube.

tain the proper clocking angle and clearance

(4).

Unclamp start pump wire harness and

needed for line installation.

disconnect plug from cell cover recep

(2). Install Sta. 124.00 firewall elbow, with

tacle.

jam nut on forward side of firewall, flat

of nut against stiffener, and washer

(5).

Unplug fuel quantity transmitter

against elbow. Torque elbow to 145 -

connector from cell cover receptacle.

155 inch-pounds (16.38 - 17.51 Nm).

(6).

Unclamp and disconnect control cable

Ensure elbow is clocked 12° - 16° to the

from fuel shutoff valve.

right from vertical after torquing.

(3). Connect flexible drain lines to drain

(7).

Unfasten and remove Sta. 91.00 and

valves and clamp in place with lock

102.00 left fuel cell cover support

wire.

brackets.

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MAINTENANCE MANUAL

Table 401. Fuel Line Torque Values

Torque

Item/Position

Inch−Pounds (Nm)

Tube end−nuts; fuel shutoff valve; Sta. 124.00 Bulkhead elbow

230 − 260 (25.99 − 29.38)

Bulkhead elbow jamnut; Sta. 124.00

145 − 155 (16.38 − 17.51)

Three−port elbow jamnut; Sta. 124.00 (if equipped)

145 − 155 (16.38 − 17.51)

Drain valves (all)

95 − 105 (10.73 − 11.86)

Hose end−nuts; firewall/engine

230 − 260 (25.99 − 29.38)

pressure port union threads. Install

CAUTION

O-ring on union. Install union in start

pump pressure port and torque to 280 -

D Do not strain or bend fuel quantity trans

305 inch-pounds (31.64 - 34.46 Nm).

mitter float arm.

D Handle fuel cell covers with care. Prying

(2). Attach fuel supply hose to start pump

covers from cell openings or rough handl

pressure port union. Torque hose nut to

ing may damage the cover seal or cell fit

230 - 260 inch-pounds (25.99 - 29.38

ting.

Nm).

(8). Remove fuel quantity transmitter

flange screws. Lift transmitter assem

CAUTION

bly out of cover opening.

D Ensure start pump wire lead is wrapped

(9). Unbolt and prop fuel cell access cover

around or tie-wrapped to fuel supply hose

open with suitably padded blocks.

so that there is no possibility of its interf

ering with fuel quantity transmitter float

(10). Use a backup wrench on valve and

mechanism. Ensure electrical connec

separate fuel supply hose from fuel

tions will not be strained by G-induced

shutoff valve.

hose movements.

(11). Remove pump electrical receptacle from

D Do not mark torque alignment stripes on

cover. Remove fuel cell cover.

fuel cell internal hardware.

(12). Unbolt fuel pump from sump mount

NOTE: Use only MS3367 ty-raps inside fuel

plate. Remove fuel pump and hose.

tanks.

(13). Remove hose and union from pump

(3). Tie-wrap or wrap pump wire around

pressure port.

supply hose. Secure wire with ty-raps

as required.

B. Start Pump Installation

(4). Clean start pump and sump plate

(Ref. Figure 404)

mount contact surfaces to establish an

electrical bond per requirements of FAA

Consumable Materials

publication, EA-AC43.13-1A and 2A.

(Ref. Section 91−00−00)

Item

Nomenclature

(5). Install start pump on sump plate with

bolts and washers. Torque bolts to 36 -

CM114

Petrolatum

46 inch-pounds (4.07 - 5.20 Nm).

(1). Apply a thin coat of petrolatum

(6). Install fuel cell cover (Ref. Fuel Cell

(CM114) to a new O-ring and pump

Cover Installation).

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MAINTENANCE MANUAL

TO ENGINE

HOSE AND FIRE

SLEEVE

WASHER

SHIM WASHER

(AS REQ'D)

NUT

HOSE ELBOW

STA 124.00

BULKHEAD

SUPPLY TUBE

HOSE

FUEL SUPPLY LINES INSTALLATION

BOLT, TORQUE; 36-46 IN. LB

HOSE NUT, TORQUE;

(4.06-5.20 NM)

230-260 IN. LB

(25.99-29.38 NM)

WASHER

UNION, TORQUE;

280-305 IN. LB

FUEL PICKUP FITTING

(31.64-34.46 NM)

STARTER PUMP

HOSE NUT, TORQUE;

O-RING

230-260 IN. LB

BOLT, TORQUE; 36-46 IN. LB

(25.99-29.38 NM)

TANK SUMP PLATE

(4.06-5.20 NM)

STRUCTURE

UNION, TORQUE;

280-305 IN. LB

(31.64-34.46 NM)

WASHER

FUEL CELL

O-RING

TANK SUMP PLATE

TANK SUMP DRAIN VALVE,

TORQUE; 95-105 IN. LB

(10.73-11.86 NM)

WASHER

BOLT, TORQUE; 36-46 IN. LB

(4.06-5.20 NM)

FUEL PICKUP INSTALLATION (369FF)

O-RING

WASHER

TANK SUMP DRAIN VALVE,

BOLT, TORQUE; 36-46 IN. LB

TORQUE; 95-105 IN. LB

(4.06-5.20 NM)

(10.73-11.86 NM)

START PUMP INSTALLATION

G28-0004-1C

Figure 404. Start Pump and Fuel Lines Installation (Sheet 1 of 4)

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CSP-HMI-2

MAINTENANCE MANUAL

6. Fuel Quantity Transmitter Replacement

(7). Calibrate quantity transmitter as

required (Ref. Fuel Quantity Transmit

A. Fuel Quantity Transmitter Removal

ter Calibration and Adjustment).

(Ref. Figure 404)

B. Fuel Quantity Transmitter Installation

Avoid fuel vapor ignition

(Ref. Figure 404)

WARNING

and fire. Use only nonspark

ing tools and explosion proof work

Consumable Materials

lights. Attach helicopter to an ap

(Ref. Section 91−00−00)

proved electrical ground. Switch OFF

Item

Nomenclature

all electrical power. Disconnect exter

CM124

Kerosene

nal power and battery before opening

fuel system. Ensure work area is ade

quately ventilated.

(1). Wipe fuel quantity transmitter flange

and cell fitting clean with kerosene

(1). Defuel helicopter. Drain remaining fuel

(CM124) on a clean lint free cloth. Wipe

from tank sump drain valve into a

parts dry.

suitable container.

(2). Position fuel quantity transmitter and

Prevent spontaneous com

flange gasket on cell with float inboard

WARNING

bustion or explosion. Never

and clear of obstructions.

use oxygen to purge or ventilate fuel

tank or fuel system components. Fuel,

(3). Install screws and washers. Progres

either vapor or liquid, will violently

sively torque screws to 20 - 25 inch-

react with an oxygen rich atmosphere.

pounds (2.26 - 2.82 Nm). Lockwire

screws.

(2). Ventilate fuel tank with an inert gas

such as nitrogen or low pressure

(4). Attach fuel quantity electrical connec

compressed air applied through filler

tor to receptacle. Lockwire connector.

neck.

(5). Perform a Fuel Quantity Transmitter

(3). Remove left fuel tank access panel from

Functional Check.

passenger/cargo compartment floor.

(6). Install left fuel tank floor access panel

(Ref. Fuel Cell Cover Installation).

(4). Unplug fuel quantity transmitter

connector from cell cover receptacle.

7. Fuel System Drain Valve Replacement

Unclamp wire harness.

A. Fuel System Drain Valve Removal

CAUTION

Avoid fuel vapor ignition

WARNING

and fire. Use only nonspark

D Do not strain or bend fuel quantity trans

ing tools and explosion proof work

mitter float arm.

lights. Attach helicopter to an ap

D Prevent fuel system contamination. In

proved electrical ground. Switch OFF

stall a cover over quantity transmitter

all electrical power. Disconnect exter

cell opening. Bag small parts to prevent

nal power and battery before opening

loss or damage.

fuel system. Ensure work area is ade

quately ventilated.

(5). Remove fuel quantity transmitter

flange screws. Lift transmitter assem

Helicopter must be defueled and

CAUTION

bly out of cover opening. Discard

drained prior to removing tank

gasket.

sump drain valve.

(6). Inspect fuel quantity transmitter as

(1). Defuel helicopter, as required. Drain

required (Ref. Fuel Quantity Transmit

remaining fuel from tank sump drain

ter Inspection).

valve into a suitable container.

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MAINTENANCE MANUAL

(2). Remove lockwire from tank sump drain

A. Fuel Cell Removal

valve.

Avoid fuel vapor ignition

WARNING

and fire. Use only nonspark

(3). Using appropriate socket or wrench,

ing tools and explosion proof work

remove drain valve.

lights. Attach helicopter to an ap

proved electrical ground. Switch OFF

B. Fuel System Drain Valve Installation

all electrical power. Disconnect exter

nal power and battery before opening

Consumable Materials

fuel system. Ensure work area is ade

(Ref. Section 91−00−00)

quately ventilated.

Item

Nomenclature

Prevent fuel system contamina

CM114

Petrolatum

CAUTION

tion. Install caps on the ends of

CM124

Kerosene

hoses, tubes and fittings as parts are re

moved. Bag and identify small parts to pre

CM702

Lockwire CRES

vent loss or damage.

(1). Defuel helicopter. Drain remaining fuel

(1).

Replace drain valve O-ring packings.

from tank sump drain valve into a

Lubricate packings with kerosene

suitable container.

(CM124), petrolatum (CM114) or jet

fuel.

Prevent spontaneous com

WARNING

bustion or explosion. Never

(2).

Install and torque sump drain valve to

use oxygen to purge or ventilate fuel

95 - 105 inch-pounds (10.73 - 11.86

tank or fuel system components. Fuel,

Nm). Lockwire valve.

either vapor or liquid, will violently

react with an oxygen rich atmosphere.

(3).

Apply a torque alignment stripe to fuel

(2). Ventilate fuel tank with low pressure

line tube, hose and fitting fasteners.

forced air or an inert gas such as

nitrogen through filler neck.

(4).

Refuel helicopter.

(3). Remove right and left fuel tank access

(5).

Check drain valve for leakage.

panels from passenger/cargo compart

ment floor.

(6).

Apply external power.

NOTE: The following procedures are required

(7).

In crew compartment; set battery

to access and separate the fuel cell intercon

switch to EXT PWR position.

nect fitting and vent system aft crossover

before either cell can be removed from its

(8).

Push fuel shutoff valve control knob in

bay.

to open valve.

(4). Unclamp fuel supply tube between fuel

shutoff valve and firewall Sta. 124.00

(9).

With 250-C20B/R2 Engine: Set START

bulkhead elbow. Using a backup

PUMP switch ON to pressurize fuel

wrench on bulkhead elbow so it will not

system.

rotate, disconnect and remove tube.

Fuel Cell Replacement

(5). With 250-C20B/R2 Engine or 250-C30

Engine With Optional Maintenance

Fuel Pump: Unclamp start pump wire

CAUTION

harness and disconnect plug from cell

cover receptacle.

D Do not work on Uniroyal fuel cell in ambi

ent temperatures below 50°F (10°C).

(6). Unplug fuel quantity transmitter

connector from cell cover receptacle.

D Do not work on Engineering Fabric Corp.

fuel cell in ambient temperatures below

(7). Unclamp and disconnect control cable

70°F (21°C).

from fuel shutoff valve.

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CSP-HMI-2

MAINTENANCE MANUAL

(8). Unfasten and remove Sta. 91.00 and

NOTE: At this point either cell may be re

102.00 left fuel cell cover support

moved, as required.

brackets from airframe structure.

(19). Remove left fuel cell as follows:

CAUTION

(a). Remove cell suspension cords (Ref.

Figure 406).

D Do not strain or bend fuel quantity trans

mitter float arm.

(b). Remove and discard forward and aft

vent sealwashers.

D Handle fuel cell covers with care. Prying

covers from cell openings or rough handl

(c). Lift inboard and outboard cell clips at

ing may damage the cover seal or cell fit

each end of baffle support rod out of

ting.

airframe hangers (Ref. Figure 405).

(9).

Remove fuel quantity transmitter

(d). Inside cell, work baffle support rod

flange screws. Lift transmitter assem

ends out of cell nipples (Ref.

bly out of cover opening.

Figure 405, detail B).

(10).

Unbolt and prop fuel cell access cover

(e). Remove support rod and baffle.

open with suitably padded blocks.

Cells are thin-walled and frag

CAUTION

(11).

Using a backup wrench on valve,

ile. Avoid snagging or dragging

separate fuel supply hose from fuel

cell over pointed or sharp edges. Do not

shutoff valve. Move fuel cell cover to get

scratch or nick any of the cell's metal fit

at remaining hardware.

tings.

(12).

With 250-C20B/R2 Engine or 250-C30

(f). Collapse and fold cell lengthwise and

Engine With Optional Maintenance

remove through floor access opening.

Fuel Pump: Unbolt start pump from

sump mount plate. Remove start pump,

(20). Remove right fuel cell as follows:

hose and cell cover. Remove pump

(a). Remove fuel filler cap and shield.

electrical receptacle from cover.

Unclamp and remove filler from cell

(13).

With 250-C30 Engine: Unbolt fuel inlet

filler neck.

fitting from sump plate. Remove fuel

(b). Remove cell suspension cords.

inlet fitting, hose and cell cover.

(c). Remove and discard forward and aft

(14).

Unbolt and remove right fuel cell access

vent sealwashers.

cover.

(d). Lift inboard and outboard cell clips at

(15).

Mop up any remaining fuel in both cells

each end of baffle support rod out of

with clean lint free cloth. Purge fuel

airframe hangers.

cells with dry, forced air or inert gas.

(e). Inside cell, work baffle support rod

(16).

Have an assistant hold the male end of

ends out of cell nipples.

the cell interconnect fitting with the

special spanner wrench. Disassemble

(f). Remove support rod and baffle.

fuel cell interconnect fitting (Ref.

Figure 405). Discard packing.

Cells are thin-walled and frag

CAUTION

ile. Avoid snagging or dragging

(17).

Remove aft vent crossover U-tube nuts

cell over pointed or sharp edges. Do not

from inside cells.

scratch or nick any of the cell's metal fit

tings.

(18).

Remove forward vent crossover tube

flange bolts and washers (Ref.

(g). Collapse and fold cell lengthwise and

Figure 403).

remove through floor access opening.

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MD Helicopters, Inc.

MAINTENANCE MANUAL

B. Fuel Cell Installation

(6). Insert baffle rod ends in nipples.

(7). Attach baffle external support hooks to

Consumable Materials

airframe hangers.

(Ref. Section 91−00−00)

Item

Nomenclature

(8). Wipe cell forward and aft vent fittings

and vent tube flanges clean with

CM114

Petrolatum

kerosene (CM124) or equivalent on a

CM124

Kerosene

clean shop towel. Wipe dry.

CM809

Nylon cord

NOTE: Do not lubricate fitting sealwashers.

Lubricants may cause seal cold flow and

Special Tools

subsequent leakage.

(Ref. Section 91−00−00)

Item

Nomenclature

(9). Install new sealwashers on aft vent

ST802

Spanner wrench

tube ends. Insert tube ends through cell

fittings and install nuts finger tight. Do

not torque at this time.

Avoid fuel vapor ignition

WARNING

(10). Position new sealwashers on cell

and fire. Use only nonspark

forward vent fittings. Slip cell fitting

ing tools and explosion proof work

lights. Attach helicopter to an ap

over vent tube.

proved electrical ground. Switch OFF

NOTE: Permatex Form-A-Gasket No. 1 may

all electrical power. Disconnect exter

be used to hold stand-off washers in place.

nal power and battery before opening

fuel system. Ensure work area is ade

(11). Sandwich one AN960-10 washer on

quately ventilated.

each side between vent tube flanges

and cell fittings. Align washers with

NOTE:

bolt holes. Install bolts with one washer

D Discard used O-rings and sealwashers.

under each bolt head and engage

Apply a thin coat of petrolatum (CM114)

several threads to keep bolt in place. Do

to all new O-rings except cell vent system

not torque bolts at this time.

sealwashers and interconnect fitting gas

(12). Fasten fuel cell sump plate to airframe

ket.

with washers and bolts. Torque bolts to

D Always test and inspect a repaired fuel

36 - 46 inch-pounds (4.07 - 5.20

cell for leaks using soap bubble, phe

Nm). Lockwire bolts.

nolphthalein or liquid stand method be

fore installing the cell in the helicopter.

(13). Install a new O-ring on sump drain

valve. Install valve and torque to 95 -

(1). Air-vacuum all debris from cell bays.

105 inch-pounds (10.73 - 11.86 Nm).

Ensure compartment liner will protect

Lockwire valve.

cell from airframe points and edges.

Repair liner as required.

NOTE: Do not lubricate fuel cell interconnect

fitting gasket. Lubrication may cause seal

(2). Wipe left and right cell interconnect

cold flow and subsequent leakage.

fitting halves clean with kerosene

(14). Thread gasket and nut onto cell

(CM124) on a clean lint free shop towel.

interconnect fitting. While having an

Wipe dry.

assistant hold the opposite end of

(3). Fold cell lengthwise and position in bay

fitting with spanner wrench (ST802)

through floor opening and unfold cell.

tighten nut. Gap between nut and

female fitting shall not be more than

(4). Align cell openings with airframe

0.005 inch (0.127 mm) after tightening.

openings.

(15). Connect powerplant supply tube to

(5). Insert baffle support rods through

firewall Sta. 124.00 bulkhead elbow.

baffle tabs (Ref. Figure 405)..

Loosely install tube support clamps,

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CSP-HMI-2

MAINTENANCE MANUAL

screws, washers and nuts (Ref.

(24). Install filler on right fuel cell filler neck

Figure 404, detail A). Using a backup

with clamp and fuel filler shield. Install

wrench on bulkhead elbow so it will not

filler cap (Ref. Figure 405).

rotate, torque tube nut to 230 - 260

inch-pounds (25.99 - 29.38 Nm).

C. Fuel Cell Cover Installation

(16).

Torque aft vent U-tube interconnect

Consumable Materials

nuts to 40 - 60 inch-pounds (4.52 -

(Ref. Section 91−00−00)

6.78 Nm).

Item

Nomenclature

CM114

Petrolatum

(17).

Torque forward vent interconnect tube

CM124

Kerosene

flange bolts to 36 - 46 inch-pounds

(4.07 - 5.20 Nm) (Ref. Figure 403).

(1).

Inspect both cell cover seals for debond

(18).

Install nylon support lacing (CM809).

ing, nicks or cuts and any other damage

Anchor both ends of cord with a bowline

having a leak producing potential.

knot (Ref. Figure 406).

Replace covers as required.

(19).

With 250-C20B/R2 Engine or 250-C30

(2).

Wipe fuel cell and cover sealing sur

Engine With Optional Maintenance

faces clean with kerosene (CM124) on a

Fuel Pump: Install union in start pump

clean lint free cloth.

pressure port with a new O-ring

packing. Torque union to 280 - 305

(3).

Install right cell cover bolts and

inch-pounds (31.64 - 34.46 Nm) (Ref.

washers (Ref. Figure 405). Progressive

Figure 404, detail B). Attach fuel

ly torque cover bolts to 70 - 90 inch-

supply hose to start pump pressure port

pounds (7.91 - 10.17 Nm) in a cross

union. Torque hose nut to 230 - 260

pattern.

inch-pounds (25.99 - 29.38 Nm).

(4).

Apply a coating of petrolatum (CM114)

to a new fuel shutoff valve/cover

Ensure start pump wire lead is

CAUTION

sealwasher. Install valve on cell cover

wrapped around or tie-wrapped

with sealwasher next to valve body and

(using only MS3367 Ty-Raps) to fuel supply

valve properly aligned to make connec

hose so that there is no possibility of its in

tion with valve control cable. Install

terfering with fuel quantity transmitter

and torque valve jamnut to 240 - 280

float mechanism. Ensure electrical connec

inch-pounds (27.12 - 31.64 Nm) (Ref.

tions will not be strained by G-induced hose

Figure 402).

movements.

(5).

With 250-C20B/R2 Engine or 250-C30

(20). Wrap pump wire around supply hose or

Engine With Optional Maintenance

secure wire with ty-raps as required.

Fuel Pump: Plug start pump wire

harness cell cover hole with a bulkhead

(21). Clean start pump and sump plate

union, sealwasher inside cover and a

mount contact surfaces to establish an

plain washer outside. Install jamnut

electrical bond per requirements of FAA

and torque to 120 - 150 inch-pounds

publication, EA-AC43.13-1A and 2A.

(13.56 - 16.95 Nm). Install cap outside

of cell. Torque cap to 120 - 150 inch-

(22). Install start pump on sump plate with

pounds (13.56 - 16.95 Nm).

bolts and washers. Torque bolts to 36 -

46 inch-pounds (4.07 - 5.20 Nm).

(6).

Position cover over cell opening.

Connect fuel supply hose to fuel shutoff

(23). With 250-C30 Engine: Attach fuel inlet

valve. Torque hose nut to 230 - 260

fitting to cell sump plate with bolts and

inch-pounds (25.99 - 29.38 Nm).

washers. Torque bolts to 36 - 46

Ensure hose will not be twisted when

inch-pounds (4.07 - 5.20 Nm).

cover is installed.

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MAINTENANCE MANUAL

0.005 IN. (0.127 MM) MAXIMUM GAP

BETWEEN NUT AND FITTING

CELL INTERCONNECT

NUT

FITTING

HELICOPTER

GASKET

NIPPLE

BAFFLE

SUPPORT ROD

FUEL CELL INTERCONNECT

BOLT, TORQUE;

70-90 IN. LB

(7.91-10.17 NM)

FILLER

GROMMET

FUEL FILLER CAP

BAFFLE SUPPORT HOOK

RIGHT FUEL CELL

ACCESS COVER

FUEL FILLER SHIELD

FUEL

CELL

BAFFLE SUPPORT ROD

FUEL TANK FILLER NECK

(2) (TYP)

AFT VENT CELL

BAFFLE SUPPORT

INTERCONNECT

(CROSS SECTION VIEW)

CLAMP

NYLON CELL

TANK BAFFLE

SUPPORT LACING

(TYP)

STA. 124.00

NUT

BULKHEAD

CLAMP

(TYP)

VENT TUBE

CELL INTERCONNECT

LEFT FUEL CELL

EMERGENCY

FITTING

ACCESS COVER

VALVE ASSY

FUEL INLET HOSE

RIGHT CELL

TUBE

UNION

FWD VENT CELL

INTERCONNECT

POWER PLANT

SUPPLY TUBE

LEFT CELL

START PUMP

(369D/E - 500N)

GASKET

TANK SUMP PLATE

NUT

G28-0005C

Figure 405. Fuel Cells

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CSP-HMI-2

MAINTENANCE MANUAL

CELL TOP ATTACHMENT

(TYP)

CELL SIDE ATTACHMENT

(TYP)

BOWLINE KNOT

START LACING WITH

BOWLINE KNOT

(FOLLOW ARROWS)

TOP OF CELL

END LACING WITH

NYLON LACING

BOWLINE KNOT

NYLON LACING

LOOP

START LACING WITH

BOWLINE KNOT

(FOLLOW ARROWS)

END LACING WITH

BOWLINE KNOT

G28-0006

Figure 406. Fuel Cell Support Lacing

(7).

With 250-C20B/R2 Engine or 250-C30

(12).

Inspect fuel quantity transmitter flange

Engine With Optional Maintenance

gasket for condition. Replace gasket if

Fuel Pump: Install start pump wiring

damaged or deteriorated. Position fuel

harness receptacle on fuel cell cover.

quantity transmitter in cell with float

inboard and clear of obstacles. Install

(8).

Install three support brackets on Sta.

screws and washers. Progressively

91.00 and 102.00 floor cross-members

torque screws to 20 - 25 inch-pounds

with washers and screws. Torque

(2.26 - 2.82 Nm). Lockwire screws.

screws to 20 - 25 inch-pounds (2.26 -

2.82 Nm).

(13).

Torque power plant fuel supply tube

nut to 230 - 260 inch-pounds (25.99 -

(9).

Finger tighten fuel supply tube nut

29.38 Nm). Tighten supply tube clamp

onto fuel shutoff valve. Position control

fasteners.

cable and electrical harness clamps on

cover.

(14).

Slip control cable through hole in fuel

(10).

Install cover bolts and washers. Install

shutoff valve lever swivel.

drilled-head bolt one bolt hole inboard

of pump electrical receptacle. Progres

(15).

Rig cable control system (Ref. Fuel

sively torque cover bolts to 70 - 90

Shutoff Valve Control Cable Installa

inch-pounds (7.91 - 10.17 Nm) in a

tion).

cross pattern.

(11).

Lockwire electrical receptacle nut to

(16).

Attach fuel quantity electrical connec

drilled bolt.

tor to receptacle. Lockwire connector.

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MAINTENANCE MANUAL

(17). With 250-C20B/R2 Engine or 250-C30

(19). With 250-C20B/R2 Engine or 250-C30

Engine With Optional Maintenance

Fuel Pump: Attach start pump electri

Fuel Pump: Perform a start pump

cal connector to receptacle. Lockwire

operation and system pressurization

connector.

check with a concurrent leak inspection

(Ref. Start Pump Operational Check

NOTE: To ensure that the C30 engine installa

(Model 250-C20 Series Engines).

tion fuel system is free of leaks you must

(20). Apply a torque alignment stripe to fuel

perform a vacuum leak test.

line tube, hose and fitting fasteners.

(18). Perform a vacuum leak inspection on

(21). Install left and right cell access panels

all helicopter models.

on cargo compartment floor.

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CSP-HMI-2

MAINTENANCE MANUAL

FUEL SYSTEM

ADJUSTMENT/TEST

1. Fuel Level Low Caution Light System Test

previously installed, replace quantity

transmitter and calibrate system.

Special Tools

(8). Remove left fuel cell floor access panel.

(Ref. Section 91−00−00)

Item

Nomenclature

(9). Ground fuel quantity transmitter

terminal D to airframe with a jumper

N/A

Inclinometer, Sperry Model 45

wire.

(10). FUEL LEVEL LOW caution lamp

should show a steady bright light.

WARNING

(11). If the light is intermittent or does not

D FUEL LEVEL LOW warning light-on

come on at all, disconnect all power and

point, either 35 pounds for commer

run a continuity check on the warning

cial helicopters or 70 pounds fuel re

light and wiring between the INSTR

maining for noncommercial ma

circuit breaker and transmitter.

chines, must comply with the fuel

low level caution light calibration

(12). If the wiring and light check out,

specified in the Pilot's Flight Manual.

remove and bench check the transmit

D A 70 pound fuel level low warning

ter assembly (Ref. Fuel Quantity

light calibration is not approved for

Transmitter Calibration and Adjust

commercial applications.

ment).

(1).

Refuel to bring fuel quantity above 35

2. Fuel Quantity Transmitter Calibration and

or 70 pound low level warning point, as

Adjustment

appropriate.

(Ref. Figure 501)

(2).

Plug in and switch on 24 - 28 Vdc

external power.

Special Tools

(Ref. Section 91−00−00)

(3).

Set battery switch to EXT PWR.

Item

Nomenclature

N/A

Test harness and No. 328 lamp

(4).

Reset INSTR circuit breaker.

(5).

Set caution and warning light dimmer

Prevent fuel vapor accumu

control on BRT.

WARNING

lation, ignition and fire. At

tach helicopter to an approved electri

(6).

Test caution and warning light array.

cal ground. Switch OFF and disconnect

Replace lamps as required.

external power and battery before

opening fuel system. Perform work in

(7).

With known fuel quantity above 35 or

an open, well ventilated area away

70 pounds, caution lamp must be off.

from all potential ignition sources. Use

Check warning light to ensure it does

only nonsparking tools and explosion

not glow or flicker. A glowing caution

proof work lights.

lamp with fuel quantity above the low

level warning point indicates that

(1). Remove fuel quantity transmitter from

current is leaking past the low level

tank. Install a cover on cell opening.

warning transistor (switch) through the

caution lamp. This problem is corrected

(2). Fabricate a stand to support quantity

by installing a resistor in the transmit

transmitter level about 11 inches (28

ter warning light circuit (Ref. Fuel

cm) above work table surface. Support

System Repairs). If resistor has been

stand must allow access to float arm.

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MAINTENANCE MANUAL

NO. 328

LAMP

BLU

RED

24 VDC

POWER

G B

SUPPLY

BLK

P251

CONNECTOR

FUEL QUANTITY

TRANSMITTER

TEST CONNECTIONS

1.75 IN. (4.45 CM)

DIA (MAX.

CONNECTOR

SEALANT

ENVELOPE)

0.75 IN. (4.45 CM) MAX.

SEALANT ENVELOPE

FULL

FLOAT STOP (FULL)

SPRING

10.08 IN.

(25.60 CM)

BRACKET

RADIUS

FLOAT STOP

(EMPTY)

8.99-9.11 IN.

(22.84-23.134CM)

SPRING CONTACT

FLOAT

2.15 IN. (5.46 CM)

(NOTE 2)

GROUND TERMINAL

EMPTY

1.25 IN.

TRANSISTOR SWITCH

(3.175 CM)

(ON UNDERSIDE)

CALIBRATION 369A4245 (EARLY UNIT)

(NOTE 1)

NOTES:

TANK UNIT

CAUTION LIGHT ON, 35 LBS REMAINING.

CONNECTIONS

CAUTION LIGHT ON, 70 LBS REMAINING.

NOT APPROVED FOR COMMERCIAL

G28-0007-1A

APPLICATION

Figure 501. Fuel Quantity Transmitter Calibration (Sheet 1 of 2)

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MAINTENANCE MANUAL

0.62 IN.

CONNECTOR

MOUNTING FLANGE

(15.75 MM)

FLOAT STOP

FULL

(FULL)

BOTTOM OF FLOAT

10.08 IN.

(25.60 CM)

SPRING

RADIUS

FLOAT STOP

8.41-8.45 IN.

(EMPTY)

(21.36-21.46 CM)

2.13-2.17 IN.

(5.41-5.51 CM)

SPRING CONTACT

(NOTE 2)

(NOTE 1)

0.91-0.95 IN.

(23.11-24.13 MM)

FLOAT

NOTES:

EMPTY

CAUTION LIGHT ON, 35 LBS REMAINING.

CAUTION LIGHT ON, 70 LBS REMAINING.

NOT APPROVED FOR COMMERCIAL

CALIBRATION 369D296303 (CURRENT UNIT)

G28-0007-2A

Figure 501. Fuel Quantity Transmitter Calibration (Sheet 2 of 2)

A. Fuel Level Calibration

(6). On part Nos. 369A4245 (early) and

369D296303 (current) transmitters:

(1).

Let float arm rest on lower stop.

(a). Attach ohmmeter leads to connector

(2).

Set an ohmmeter on its low resistance

pins B and H.

scale. Measure resistance across

connector pins B and H.

(b). Raise float arm against upper stop.

(c). Indicated resistance shall be 88 - 95

Part number 369A4245 (early) quantity

ohms.

transmitter resistance must be 0 - 3

ohms.

(d). Bend stop to adjust resistance value.

P/N 369D296303 (current) units must

(e). Measure float travel between empty

and full stops. Ensure travel is

within limits (Ref. Figure 501).

(3).

Bend float stop down to decrease, or up

to increase resistance.

(7). Disconnect ohmmeter.

(4).

Raise float arm to contact upper stop.

B. Fuel Level Low Warning Light Calibration

(5).

On 369A4245 (early) quantity transmit

(1). Fabricate test harness incorporating a

ters only, measure resistance between

No. 328 lamp bulb and P251 female

steel wire spring support bracket and

connector half. Alternatively, fabricate

mounting flange. Resistance must be

test wires with individual insulated

greater than 2 megohms.

tubular pin connectors.

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MAINTENANCE MANUAL

(2). Attach test harness to transmitter

(5). Check P/N 369D296303 and

connector pins D and H and power

369D296303-701 (current) transmitter

source.

units as follows:

(a).

Hold float arm between stops. Test

(3). Switch on 24 Vdc power.

lamp must be off. A glowing lamp

indicates that current is leaking past

(4). Check P/N 369A4245 (early) transmit

transistor (lamp switch).

ter units as follows:

The problem is corrected by installing

(a). Hold float arm between stops. Test

a 510 ohm resistor in the transmitter

lamp must be off. A glowing lamp

caution light circuit (Ref. Fuel

indicates that current is leaking past

System Repairs).

transistor (lamp switch). The prob

lem is corrected by installing a 510

If resistor has been previously

ohm resistor in the transmitter

installed, replace quantity transmit

caution light circuit (Ref. Fuel

ter.

System Repairs). If resistor has been

previously installed, replace quantity

(b).

Lower float arm to just touch bracket

transmitter.

supported steel wire.

(c).

Test lamp should come on.

(b). Lower float arm until it just contacts

bracket supported steel wire:

(d).

Mark arm/float centerline position on

a ruler or stick where lamp comes on.

(c). Test lamp should come on.

(e).

Lower float. Mark ruler at arm/float

(d). Mark arm/float centerline position on

centerline position with float bot

a ruler or stick at point where lamp

tomed on stop.

comes on.

(f).

Measured distance between upper

and lower marks shall be:

(e). Lower float. Mark ruler at arm/float

centerline position with float bot

0.91 - 0.95 inch (23.11 - 24.39 mm)

tomed on stop.

for 35 pounds (nominal) fuel remain

ing.

WARNING

2.13 - 2.17 inch (5.41 - 5.51 cm) for

70 pounds (nominal) fuel remaining.

D FUEL LEVEL LOW warning light-on

point, either 35 pounds for commer

(6). Bend transmitter bracket spring wire to

cial helicopters or 70 pounds fuel re

adjust light-on position as required.

maining for noncommercial ma

chines, must comply with the fuel

(7). Check that lamp operation and float

low level caution light calibration

dimensions are within specified

specified in the Pilot's Flight Manual.

tolerances.

D A 70 pound fuel level low warning

(8). Disconnect electrical power and test

light calibration is not approved for

equipment.

commercial applications.

3. Fuel Quantity Transmitter Functional

(f). Distance between upper and lower

Check

marks shall be:

Special Tools

1.25 inch (3.18 cm) for 35 pounds

(Ref. Section 91−00−00)

(nominal) fuel remaining.

Item

Nomenclature

2.15 inch (5.46 cm) for 70 pounds

N/A

Inclinometer, Sperry Model 45

(nominal) fuel remaining.

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MAINTENANCE MANUAL

Avoid fuel vapor accumula

(12). Disconnect fuel supply hose from

WARNING

tion, ignition and fire. Use

engine.

only non-sparking tools and explosion

(13). Have an assistant direct fuel hose into

proof work lights. Attach helicopter to

a suitable 10 gallon (37.85 L) container.

an approved electrical ground. Switch

Push fuel control valve knob in to open

OFF all electrical power. Disconnect

fuel shutoff valve.

external power and battery before

opening fuel system. Ensure work area

(14).

(C20 Series Engines) Set fuel start

is adequately ventilated.

pump switch to START PUMP.

(1). Attach helicopter to an approved

(15).

(C30 Engine) Attach a siphon pump to

electrical ground.

fuel supply hose to suck fuel out of

tank.

(2). Defuel and drain fuel tank.

(16). Pump 0.5 - 1.5 gallons (1.89 - 5.68 L),

(3). Locate inclinometer on rear deck

3.0 - 10.0 pounds (1.36 - 4.54 kg) out of

between Sta. 100 and 104.

the fuel tank while observing fuel

gauge for erratic or hung movement.

(4). Jack and level helicopter or spot

Fuel quantity gauge needle shall range

helicopter on level ground.

between 34 - 42 pounds.

(5). Jack helicopter to get a 2° nose down

NOTE:

attitude on the inclinometer. Stabilize

D (C20 Series Engines) A stuck needle on

helicopter with blocks as required.

a new, calibrated and tested gauge may be

due to transmitter float contact with the

(6). Reset INST and PNL LT circuit

start pump wire, pump or supply hose.

breakers.

D (C30 Engine) Transmitter float interfer

(7). Apply external power. Set battery

ence may be caused by the supply hose or

switch to EXT PWR.

sump pickup fitting.

(17).

Loosen fuel quantity transmitter

NOTE: All gauge readings are taken from the

mounting flange screws. Rotate

centerline of the fuel quantity indicator

transmitter clockwise as far as it will

pointer.

move and tighten screws. Check gauge

(8). Check that fuel quantity gauge needle

needle position.

points to empty, E with the pointer

(18).

If float interference problem persists,

centerline between the outer and inner

remove quantity transmitter and

edge of the E graduation mark. Check

determine action required to eliminate

that FUEL LEVEL LOW warning

problem; i.e. reposition transmitter

light is on.

float arm, fuel supply hose and, or start

NOTE: Do not bend float arm for adjustment of

pump wire.

fuel quantity indicating system.

(19).

Install transmitter and repeat function

al check.

(9). If adjustments are required; shut down

external electrical power, and remove

(20).

When 10 pounds (4.54 kg), 1.53 gallons

transmitter, bend float stops as re

(5.79 L) has been pumped, needle

quired and re-install transmitter.

pointer should be aligned on center of

the 35 pound red dot mark and FUEL

(10). Pump seven gallons of fuel into tank.

LOW caution light should come on.

(11). Apply external power. Set battery

(21).

Drain remaining fuel and observe that

switch to EXT PWR.

gauge needle falls to empty (E) as tank

runs dry.

FUEL LEVEL LOW warning light

should be out, and gauge should

(22).

Repeat adjustments as required.

indicate approximately 45 pounds.

Additional adjustments to float arm or

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MAINTENANCE MANUAL

low level contact wire requires a

(4). Disconnect hose from from switch

verification check and repetition of the

bushing. Cap hose.

entire check procedure sequence.

(5). Remove fuel pressure switch with

bushing intact from after filter (AF)

(23). Connect fuel supply hose to engine inlet

port adapter. Install an O-ring on a

port. Torque hose nut to 230 - 260

suitable airtight plug and tighten into

inch-pounds (25.99 - 29.38 Nm).

adapter fitting.

(24). Install quantity transmitter (Ref. Fuel

(6). Bench test 369H8144 bypass pressure

Quantity Transmitter Installation).

switch as follows (denoted by three

housing screws):

4. Fuel Filter (Bypass) Caution Light

(a). Assemble test equipment shown in

Pressure Switch Test

Figure 502. Connect tester to pres

sure switch lead and connect ground

WARNING

test lead to one of three screws on the

housing body.

D Air in the fuel system will cause a

power reduction or flameout. Do a

(b). Remove bushing and O-ring from

fuel system vacuum leak check and

switch. Attach tubing to switch inlet

system air bleed after opening fuel

port as shown. Wipe switch complete

system to atmosphere and prior to

ly dry so any leakage can be detected

releasing helicopter for flight.

during the test.

D (Model 250-C20 Series Engines) En

(c). Add fuel to tube. Ohmmeter must

sure start pump is operating before

indicate switch contact closure as

taking fuel samples from system sup

fuel column height passes between

ply line drain valves.

24.5 and 35.0 inches (62.23 and 88.90

cm).

(1). Set all switches; OFF. Disconnect

(d). Check switch for leakage around

external electrical power. Disconnect

diaphragm. No leaks allowed.

battery.

Replace a leaking switch.

(2). Open engine access doors.

(e). Separate switch from test apparatus.

(3). Locate pressure switch on engine fuel

(f). Install new O-ring and bushing on

pump filter (Ref. Figure 503, Figure 504

switch. Torque switch bushing.

or Figure 505). Disconnect bypass

(7). Bench test 369D28144 bypass pressure

switch wire knife splice.

switch as follows (denoted by six

housing screws):

CAUTION

(a). Assemble test equipment shown in

Figure 502. Connect tester to pres

D Pressure switch is easily damaged. A

sure switch lead and connect ground

slight shearing force applied to half the

test lead to one of six screws on the

pressure switch can cause leakage and, or

housing body.

operational failure. Always grip both

halves of pressure switch hex flats with

(b). Pressure Method:

wrench when loosening or torquing at

taching hardware.

1). Remove bushing and O-ring from

switch. Attach tubing to switch

D Bypass pressure switch is not field repair

port A as shown. Tubing has to be

able. Do not disassemble switch. Return

airtight.

faulty switches to vender for repair.

2). Add pressure to the tube. Ohmme

NOTE: For all torques in the following proce

ter must indicate switch contact

dures, refer to Figure 503, Figure 504 or

closure as pressure passes between

Figure 505.

8 - 9 psig (16.3 - 18.3 in. hg.).

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3). Hold pressure for five minutes and

(e).

Set battery switch to EXT PWR.

check for bleed-off. Any bleed-off

(f).

Reset INSTR circuit breaker.

indicates a leak in the switch and

requires switch replacement.

(g).

Set caution and warning light

dimmer control on BRT.

4). Slowly release pressure. Ohmme

ter must indicate switch contact

(h).

Test caution and warning light array.

opening by 4 psig (8.1 in. hg).

Replace lamps as required.

(c). Vacuum Method:

(i).

Connect a jumper wire between

switch body and airframe ground

1). Remove bushing and O-ring from

E12.

switch. Attach tubing to switch

port B as shown. Tubing has to be

(j).

Set start pump switch; ON. FUEL

airtight.

FILTER caution light should come

on. If FUEL FILTER caution light

2). Add vacuum to the tube. Ohmme

fails to light but works when tested,

ter must indicate switch contact

switch is probably faulty. Replace

closure as vacuum passes between

switch and repeat operational test.

8 - 9 psig (16.3 - 18.3 in. hg.).

(k).

Check switch diaphragm for leakage

3). Hold vacuum for five minutes and

through open port while pressurized.

check for bleed-off. Any bleed-off

Replace a leaky switch.

indicates a leak in the switch and

requires switch replacement.

(l).

Disconnect jumper wire between

pressure switch and ground. Set start

4). Slowly release vacuum. Ohmmeter

pump switch; OFF. Set battery

must indicate switch contact

switch; OFF. Disconnect external

opening as vacuum reaches 4 psig

power and battery.

(8.1 in. hg).

(m).

Disconnect bypass hose from switch

(d). Separate switch from test apparatus.

bushing. Install an airtight cap on

hose.

(e). Install new O-ring and bushing on

switch. Torque switch bushing.

(n).

Remove plug from adapter fitting.

Install bypass switch assembly and a

(8).

(Model 250-C20B/R2 Series Engines)

new O-ring in adapter fitting. Torque

Perform a switch operational check as

switch assembly.

follows:

(o).

Remove plug from bypass hose.

(a). Uncap and attach bypass hose to

Attach hose to switch bushing.

bushing. Torque hose nut.

Torque hose nut.

(b). Install a suitable airtight plug and

(p).

Install insulating sleeve and connect

O-ring in adapter fitting.

switch wire knife splice.

(c). Connect and insulate switch wire

(q).

Bleed fuel system.

knife splice.

(r).

Operate engine per Pilot's Flight

(d). Have an assistant hold switch clear

Manual and check fuel system for

of adjacent structures. Connect

correct operation. Shut down engine.

battery and external electrical power.

Inspect fuel system for leaks.

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MAINTENANCE MANUAL

PRESSURE METHOD:

APPLY 8-9 PSIG (16.3-18.3 IN. HG.) TO CLOSE SWITCH.

BLEED OFF TO 4 PSIG (8.1 IN. HG.) TO OPEN SWITCH.

PORT A

NOTE 2

36 INCH

SCALE

3/8” TYGON TUBING

OHMMETER

36 IN.

(OR EQUIV.)

CONTINUITY TESTER

PORT B

VACUUM METHOD:

APPLY 8-9 PSIG (16.3-18.3 IN. HG.) TO CLOSE SWITCH.

PORT A

BLEED OFF TO 4 PSIG (8.1 IN. HG.) TO OPEN SWITCH.

369D28144 FUEL FILTER

NOTE 1

PRESSURE SWITCH

FUEL FILTER

PRESSURE SWITCH

OHMMETER

CONTINUITY TESTER

PORT B

369H8144 FUEL FILTER

PRESSURE SWITCH

NOTES:

CONNECT GROUND TEST LEAD TO ONE OF

THREE SCREW HEADS ON THE HOUSING BODY.

CONNECT GROUND TEST LEAD TO ONE OF

G28-0010B

SIX SCREW HEADS ON THE HOUSING BODY

Figure 502. Fuel Filter Caution Light Pressure Switch Test (C20/C30 Engines)

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MAINTENANCE MANUAL

ELBOW, TORQUE: 75-85 IN. LB

(8.47-9.60 NM)

BEFORE FILTER

REDUCER, TORQUE; 95-105 IN. LB

PORT (BF)

(10.73-11.86 NM)

FITTING, TORQUE; 95-105 IN. LB

ENGINE FUEL

(10.73-11.86 NM)

PUMP FILTER

FUEL FILTER PRESSURE SWITCH,

TORQUE; 90-100 IN. LB (10.16-11.30 NM)

ELBOW, TORQUE; 75-85 IN. LB

(8.47-9.60 NM)

HOSE

G28-0009B

Figure 503. Fuel Filter Caution Light Pressure Switch (C30 Engine)

ENGINE FUEL

PUMP FILTER

AFTER FILTER

O-RING

BEFORE FILTER

PORT (AF)

PORT (BF)

REDUCER, TORQUE; 65-75 IN. LB

(7.34-8.47 NM)

HOSE

FITTING, TORQUE; 65-75 IN. LB

(7.34-8.47 NM)

O-RING

FUEL FILTER PRESSURE SWITCH,

ELBOW, TORQUE; 75-85 IN. LB

TORQUE; 60-75 IN. LB (6.78-8.47 NM)

(8.47-9.60 NM) (2 PL)

O-RING

BUSHING, TORQUE; 90-100 IN. LB

(10.16-11.30 NM)

G28-0008B

Figure 504. Fuel Filter Caution Light Pressure Switch (C20 Engines)

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HANDBOOK OF MAINTENANCE INSTRUCTIONS FOR MDHI 369D/E/FF-500/600N HELICOPTERS (ISSUED: 1990) - page 10