407-MM-CH28

BHT-407-MM-4

28-00-0016 FEB 2012 Rev. 34 ECCN EAR99

TABLE OF CONTENTS

Paragraph Chapter/Section Page Number Title Number Number

CHAPTER 28 — FUEL SYSTEM

FUEL SYSTEM

28-1 Fuel System — Description ........................................................... 28-00-00 528-2 Fuel System Components — Description................................. 28-00-00 528-3 Fuel System Components — Fuel Cells ........................... 28-00-00 528-4 Fuel System Components — Fuel Transfer System......... 28-00-00 728-5 Fuel System Components — Gravity Fuel Transfer

System .............................................................................. 28-00-00 728-6 Fuel System Components — Pressure Fuel Transfer

System .............................................................................. 28-00-00 728-6A Fuel System Components — L/FUEL XFR and R/FUEL

XFR Annunciators (S/N 53000 Through 53174) ............... 28-00-00 728-6B Fuel System Components — L/FUEL XFR and R/FUEL

XFR Annunciators (S/N 53175 and Subsequent) ............. 28-00-00 828-7 Fuel System Components — Engine Fuel Feed System.. 28-00-00 928-7A Fuel System Components — Left Fuel Boost/XFR

Alternate Electrical Circuit ................................................. 28-00-00 928-8 Fuel System Components — Vent System....................... 28-00-00 928-9 Fuel System Components — Fuel Quantity Indicating

System .............................................................................. 28-00-00 1128-10 Fuel System Components — Low Level Warning System 28-00-00 1128-11 Fuel System Components — Refueling/Defueling............ 28-00-00 1228-12 Fuel System Components — Auxiliary Fuel Cell Kit ......... 28-00-00 1228-13 Fuel System Components — Fuel Cell Draining .............. 28-00-00 1228-14 Fuel System Components — Miscellaneous .................... 28-00-00 1228-15 Fuel System Components — Flight Compartment

Controls and Indications ................................................... 28-00-00 1328-16 Fuel System — Operation ........................................................ 28-00-00 1428-17 Fuel System — Handling and Safety Precautions.................... 28-00-00 14B28-18 Fuel System — Troubleshooting .............................................. 28-00-00 14C28-19 Fuel System — Pressure Test.................................................. 28-00-00 14C28-20 Fuel System — Operational Check .......................................... 28-00-00 14C28-21 Forward and Main Fuel Cell — Inspection................................ 28-00-00 1528-22 Fuel Storage .................................................................................. 28-00-00 1628-23 Forward Fuel Cell ..................................................................... 28-00-00 1628-24 Forward Fuel Cell — Removal.......................................... 28-00-00 1628-25 Forward Fuel Cell — Inspection, Cleaning and Repair ..... 28-00-00 1828-26 Forward Fuel Cell — Installation....................................... 28-00-00 1828-27 Main Fuel Cell........................................................................... 28-00-00 2028-28 Main Fuel Cell — Removal ............................................... 28-00-00 2028-29 Main Fuel Cell — Inspection, Cleaning and Repair .......... 28-00-00 2228-30 Main Fuel Cell — Installation ............................................ 28-00-00 2228-31 Fuel Distribution ............................................................................. 28-00-00 2328-32 Fuel Transfer Pump Assembly ................................................. 28-00-00 2428-33 Fuel Transfer Pump Assembly — Removal...................... 28-00-00 2428-34 Fuel Transfer Pump Assembly — Inspection.................... 28-00-00 24

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TABLE OF CONTENTS (CONT)


28-35 Fuel Transfer Pump Assembly — Installation................... 28-00-00 2628-36 Fuel Transfer Pump Cartridge .................................................. 28-00-00 2628-37 Fuel Transfer Pump Cartridge — Removal....................... 28-00-00 2628-38 Fuel Transfer Pump Cartridge — Inspection .................... 28-00-00 2828-39 Fuel Transfer Pump Cartridge — Installation.................... 28-00-00 2828-40 Fuel Transfer Pump Check Valve............................................. 28-00-00 2928-41 Fuel Transfer Pump Check Valve — Removal ................. 28-00-00 2928-42 Fuel Transfer Pump Check Valve — Inspection ............... 28-00-00 2928-43 Fuel Transfer Pump Check Valve — Installation .............. 28-00-00 3128-44 Fuel Transfer Pump Pressure Switch ....................................... 28-00-00 3128-45 Fuel Transfer Pump Pressure Switch

— Removal/installation ..................................................... 28-00-00 3128-46 Fuel Transfer Pump Sump Drain/Defuel Valve......................... 28-00-00 3128-47 Fuel Transfer Pump Sump Drain/Defuel Valve

— Removal ....................................................................... 28-00-00 3128-48 Fuel Transfer Pump Sump Drain/Defuel Valve

— Inspection ..................................................................... 28-00-00 3128-49 Fuel Transfer Pump Sump Drain/Defuel Valve

— Installation .................................................................... 28-00-00 3328-50 Fuel Boost Pump Assembly...................................................... 28-00-00 3328-51 Fuel Boost Pump Assembly — Removal .......................... 28-00-00 3328-52 Fuel Boost Pump Assembly — Inspection........................ 28-00-00 3528-53 Fuel Boost Pump Assembly — Installation ....................... 28-00-00 3528-54 Fuel Boost Pump Cartridge ...................................................... 28-00-00 3628-55 Fuel Boost Pump Cartridge — Removal........................... 28-00-00 3628-56 Fuel Boost Pump Cartridge — Inspection......................... 28-00-00 3628-57 Fuel Boost Pump Cartridge — Installation........................ 28-00-00 3828-58 Fuel Boost Pump Check Valve ................................................. 28-00-00 3828-59 Fuel Boost Pump Check Valve — Removal ..................... 28-00-00 3828-60 Fuel Boost Pump Check Valve — Inspection ................... 28-00-00 38B28-61 Fuel Boost Pump Check Valve — Installation .................. 28-00-00 3928-62 Fuel Boost Pump Pressure Switch ........................................... 28-00-00 3928-63 Fuel Boost Pump Pressure Switch — Removal and

Installation......................................................................... 28-00-00 3928-64 Fuel Boost Pump Sump Drain/Defuel Valve............................. 28-00-00 3928-65 Fuel Boost Pump Sump Drain/Defuel Valve

— Removal ....................................................................... 28-00-00 3928-66 Fuel Boost Pump Sump Drain/Defuel Valve

— Inspection ..................................................................... 28-00-00 3928-67 Fuel Boost Pump Sump Drain/Defuel Valve

— Installation .................................................................... 28-00-00 4128-68 Fuel Cell Interconnect System.................................................. 28-00-00 4128-69 Fuel Cell Interconnect — Removal ................................... 28-00-00 4128-70 Fuel Cell Interconnect — Inspection ................................. 28-00-00 4428-71 Fuel Cell Interconnect — Installation ................................ 28-00-00 4528-72 Fuel Pressure Transducer ........................................................ 28-00-00 4628-73 Fuel Pressure Transducer — Removal and Installation ... 28-00-00 4628-74 Fuel Pressure Transducer — Inspection .......................... 28-00-00 46

BHT-407-MM-4

28-00-0018 JUN 2013 Rev. 36 Export Classification C, ECCN EAR99

TABLE OF CONTENTS (CONT)


28-75 Fuel Shutoff Valve .................................................................... 28-00-00 4628-76 Fuel Shutoff Valve — Removal......................................... 28-00-00 46A28-77 Fuel Shutoff Valve — Inspection....................................... 28-00-00 4828-78 Fuel Shutoff Valve — Installation...................................... 28-00-00 4828-79 Fuel Filter Assembly ................................................................. 28-00-00 4828-80 Fuel Filter Assembly — Removal...................................... 28-00-00 4828-81 Fuel Filter Assembly — Inspection ................................... 28-00-00 5028-82 Fuel Filter Assembly — Installation................................... 28-00-00 5028-83 Fuel Filter Element.................................................................... 28-00-00 50A28-84 Fuel Filter Element — Replacement ................................. 28-00-00 50A28-85 Fuel Indication................................................................................ 28-00-00 5128-86 Forward Fuel Cell Fuel Quantity Probe .................................... 28-00-00 5128-87 Forward Fuel Cell Fuel Quantity Probe — Removal......... 28-00-00 5128-88 Forward Fuel Cell Fuel Quantity Probe — Inspection....... 28-00-00 5428-89 Forward Fuel Cell Fuel Quantity Probe — Installation...... 28-00-00 5428-90 Forward Fuel Cell Low Level Switch......................................... 28-00-00 5428-91 Forward Fuel Cell Low Level Switch — Removal ............. 28-00-00 5428-92 Forward Fuel Cell Low Level Switch — Inspection........... 28-00-00 5428-93 Forward Fuel Cell Low Level Switch — Installation .......... 28-00-00 5628-94 Aft Fuel Quantity Probe ............................................................ 28-00-00 5628-95 Aft Fuel Quantity Probe — Removal ................................. 28-00-00 5628-96 Aft Fuel Quantity Probe — Inspection............................... 28-00-00 5828-97 Aft Fuel Quantity Probe — Installation.............................. 28-00-00 5828-98 Mid Level Fuel Quantity Probe ................................................. 28-00-00 5828-99 Mid Level Fuel Quantity Probe — Removal...................... 28-00-00 5928-100 Mid Level Fuel Quantity Probe — Inspection.................... 28-00-00 5928-101 Mid Level Fuel Quantity Probe — Installation................... 28-00-00 5928-102 Fuel Quantity Harness .............................................................. 28-00-00 6128-103 Fuel Quantity Harness — Removal .................................. 28-00-00 6128-104 Fuel Quantity Harness — Inspection ................................ 28-00-00 6428-105 Fuel Quantity Harness — Installation ............................... 28-00-00 6428-106 Main Fuel Cell Low Level Switch .............................................. 28-00-00 6528-107 Main Fuel Cell Low Level Switch — Removal .................. 28-00-00 6528-108 Main Fuel Cell Low Level Switch — Inspection ................ 28-00-00 6728-109 Main Fuel Cell Low Level Switch — Installation ............... 28-00-00 67

FIGURES

Figure Page Number Title Number

28-1 Fuel System ........................................................................................................ 628-1A Left Fuel Boost/XFR Alternate Circuit Schematic ............................................... 1028-2 Fuel System Schematic ...................................................................................... 14A28-3 Forward Fuel Cell................................................................................................ 1728-4 Main Fuel Cell ..................................................................................................... 2128-5 Fuel Transfer Pump Assembly............................................................................ 25

BHT-407-MM-4

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FIGURES (CONT)

Figure Page Number Title Number

28-6 Fuel Transfer Pump Cartridge ............................................................................ 2728-7 Fuel Transfer Pump Check Valve ....................................................................... 3028-8 Fuel Transfer Pump Sump Drain/Defuel Valve................................................... 3228-9 Fuel Boost Pump Assembly................................................................................ 3428-10 Fuel Boost Pump Cartridge................................................................................. 3728-11 Fuel Boost Pump Check Valve ........................................................................... 38A28-12 Fuel Boost Pump Sump Drain/Defuel Valve ....................................................... 4028-13 Fuel Cell Interconnect Tube Assembly ............................................................... 4328-14 Fuel Shutoff Valve............................................................................................... 4728-15 Fuel Filter Assembly ........................................................................................... 4928-16 Fuel Filter Element.............................................................................................. 5228-17 Forward Fuel Cell Fuel Quantity Probe............................................................... 5328-18 Forward Fuel Cell Low Level Switch................................................................... 5528-19 Aft Fuel Quantity Probe....................................................................................... 5728-20 Mid Level Fuel Quantity Probe............................................................................ 6028-21 Fuel Quantity Harness ........................................................................................ 6228-22 Main Fuel Cell Low Level Switch ........................................................................ 66

TABLES

Table Page Number Title Number

28-1 Transfer Annunciator/CAS Message (407GX) Activation Table, S/N 53175and Subsequent.................................................................................................. 8

28-2 Flight Compartment Controls and Indications..................................................... 13

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FUEL SYSTEM

28-1. FUEL SYSTEM — DESCRIPTION

The fuel system (Figure 28-1) consists of two crashresistant, bladder type fuel cells. The forward fuel cellis located underneath and between the aft facingpassenger seats. The aft fuel cell is locatedunderneath and behind the aft passenger seats.

Both fuel cells are serviced through the filler portlocated on the right side of the helicopter.Approximately 28.4 U.S. gallons (193.1 pounds) offuel will accumulate in the aft main fuel cell, prior to theforward cell being filled through the gravity feed standpipe. The gravity feed stand pipe connects the aft fuelcell to the forward tank. As the aft fuel cell fills beyondthe level of the top of the stand pipe, the forward tankwill be completely filled (forward tank fuel capacity37.6 U.S. gallons (256.0 pounds). The aft tank willthen be filled to the level of the filler port (usable fuelcapacity 127.8 U.S. gallons (869.0 pounds).

If the auxiliary tank is installed, it will be filled at thesame time as the aft tank through two openingslocated on the lower aft wall of the main fuel cell,which are connected to the bottom of the auxiliary tank(refer to BHT-407-II-6/BHT-407-FMS-6 for informationon this kit).

Fuel from the forward tank is transferred to the maintank by two transfer pumps mounted on a sump plateassembly located on the bottom of the forward fuelcell. Fuel from the main fuel cell will be supplied to theengine through two boost pumps located at the baseof the main fuel cell on a sump plate. The fuel from thetwo boost pumps joins into a common fuel line thatpasses through a fuel shutoff valve, then through anairframe mounted fuel filter before reaching the enginedriven pump on the HMU. A solenoid sump drain valveis installed on the sump plate assemblies of both theforward and aft fuel tanks. The drain valves areactivated by two switches located on the right handside of the lower aft fuselage. These switches aredeactivated when the fuel valve switch is ON toprevent inadvertent activation during flight.

28-2. FUEL SYSTEM COMPONENTS —DESCRIPTION

The fuel system is made up of the components thatfollow:

• Fuel cells (forward and main)

• Gravity transfer system

• Pressure transfer system

• Engine feed system (with fuel shutoff valve,fuel filter, and a fuel pressure transducer)

• Fuel vent system

• Fuel quantity indicating system (Chapter 96)

• Low level warning system (Chapter 96)

• Refueling/defueling (Chapter 12)

• Auxiliary fuel cell kit

• Fuel cell draining (Chapter 12)

• Miscellaneous

• Flight compartment controls and indications

28-3. Fuel System Components — Fuel Cells

The fuel cells are installed in fuel cell compartmentsthat provide support on all sides. The cells have acombined total usable fuel capacity of 127.8 U.S.gallons (869.0 pounds). The forward fuel cell isinstalled between FS 74.0 and FS 100.0. The mainfuel cell is installed between FS 121.0 and FS 155.0.Both fuel cells are made from high puncture resistantmaterial.

The forward fuel cell has three major fittings: Afitting close to the top at the center of the forward facemating with the vent system, a large oval fittinginstalled on the bottom face on the helicoptercenterline for the sump plate/transfer pump, and afitting on the bottom centre of the aft face mating withthe transfer line system. Three double-sided threadedfittings are installed in the upper face of the cell toprovide a mount surface for the forward fuel probe.Four additional double threaded fittings are installed toprovide support mounts for the fuel cell to thehelicopter structure.

BHT-407-MM-4

28-00-00 Rev. 27 26 FEB 2010 ECCN EAR99

Figure 28-1. Fuel System (Sheet 1 of 2)407MM_28_0001

13

SEE DETAIL B

12

11

14

10

7

10

49

8

6

5

3

2

1

SEE DETAIL A

BHT-407-MM-4

28-00-00

ECCN EAR99

Figure 28-1. Fuel System (Sheet 2 of 2)407MM_28_0002

DETAIL B

DETAIL A

Forward fuel cellFuel transfer pump assemblyForward fuel quantity probeFuel cell interconnect tubeMid level fuel quantity probeFuel fill portAft fuel quantity probeMain fuel cellFuel boost pump assemblyAuxiliary fuel cell mountsFuel vent systemFuel shutoff valveFuel filterFuel pressure transducer

1.2.3.4.5.6.7.8.9.

10.11.12.13.14.

9

2

26 FEB 2010 Rev. 27 Page 6A/6B

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The main fuel cell has six major fittings: A fitting onthe right side of the top face that mates with the ventand fuel feed lines; a large oval fitting on thecenterline, at the bottom, for the sump plate/boostpump, and a fitting on the bottom centerline, at theforward end of the main fuel cell, that mates with thetransfer lines; a round flange in the top face to the rightof the centerline of the cell to supply a mount surfacefor the aft fuel quantity probe; and two flanges,installed on the lower aft face of the main fuel cell, thatprovide an interface with the auxiliary fuel cell kit. Inaddition, there are threaded fittings on the uppersurface to provide support for the fuel cell walls to thehelicopter structure and double sided threaded fittingsto provide a mount for the mid level fuel quantityprobe.

28-4. Fuel System Components — Fuel TransferSystem

Fuel is transferred between the main and forward fuelcells by two methods. The first method is by a gravitytransfer line that permits fuel to transfer from the mainfuel cell to the forward fuel cell. This occurs when thelevel of fuel in the main cell is above the standpipeinstalled in the main fuel cell. The second method is apressure transfer line, which transfers fuel suppliedfrom the fuel transfer pump in the forward fuel cell tothe main fuel cell.

28-5. Fuel System Components — Gravity FuelTransfer System

The gravity transfer system is made up of a flexiblehose assembly connected to the forward and main fuelcells and a standpipe in the main cell. During therefueling cycle, the level of fuel in the main fuel cellincreases until it gets to the height of the standpipe(approximately 193.1 pounds of fuel) and the fuelbegins to transfer towards the forward fuel cell. Duringfuel burn, the standpipe lets the fuel return to the mainfuel cell from the forward fuel cell. This maintains anequal fuel level in each tank until the fuel level in themain tank reaches the standpipe height. When the fuelin the main fuel cell is below the standpipe height, theforward fuel cell will be emptied into the main fuel cellby the forward fuel cell transfer pumps. The gravitytransfer also supplies a conduit between the two cellsfor the fuel quantity harness.

28-6. Fuel System Components — PressureFuel Transfer System

The pressure transfer system is made up of twotransfer pumps installed on a common sump plate onthe bottom of the forward fuel cell. Two check valvesare installed on the transfer pump outlets. A tubeassembly, a hose assembly, and an orifice installed ona tee fitting, connect the supply from each pump androute it to the forward fuel cell external fitting. A hoseassembly connects the forward fuel cell to the mainfuel cell. Two pressure switches, installed on the pumpsump plate, indicate transfer pump operation. A floatswitch type low level detector indicates when theforward fuel cell is empty. The transfer pumps runcontinuously until the forward fuel cell is empty.

When the forward fuel cell is empty, the transferpumps run for an additional period of time before theyswitch off automatically. This ensures that anyremaining fuel in the forward fuel cell will be removed.For additional information on the transfer pumps andthe L/FUEL XFR and R/FUEL XFR annunciators/CrewAlerting System (CAS) messages (407GX), refer toparagraph 28-6A and paragraph 28-6B.

A tee fitting is located at the aft attachment fitting ofthe pressure line out from the forward transfer pumpsto the aft tank. One side of the tee fitting has an orificethat permits fuel to bleed back into the forward tank ona continuous basis. This bleed back makes allowancefor the high volume output of the transfer pumps.

28-6A. Fuel System Components — L/FUEL XFRand R/FUEL XFR Annunciators (S/N 53000Through 53174)

The L/FUEL XFR and R/FUEL XFR annunciators willilluminate when their respective fuel pressure switchsenses a decreasing boost pump output pressure of1.5 ±0.5 PSI. When boost pump pressure is increasingthe annunciators will extinguish prior to the pressurepassing through 5 PSI.

Fuel must be present in the forward fuel cell for theannunciator circuits to operate since they are bothcontrolled by the fuel signal conditioner. When theforward fuel cell is nearing depletion the signalconditioner uses time delays to control the transferpumps and annunciators. The time delay allowscontinued operation of the transfer pumps to ensure allof the fuel in the forward tank is transferred to the mainfuel tank. The forward fuel cell will be empty whenapproximately 193.1 pounds of total fuel is indicated.

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The fuel signal conditioner time delay which controlsthe L/FUEL XFR pump circuit is provided by the FUELXFR/BOOST LEFT circuit breaker. The fuel signalconditioner time delay which controls the R/FUEL XFRpump circuit is provided by the FUEL XFR/ BOOSTRIGHT circuit breaker.

The L/FUEL XFR and R/FUEL XFR annunciatorcircuits will remain operational during the time delayand will illuminate in the event transfer pump outputpressure drops below 1.5 ±0.5 PSI.

Once the time delay periods are ended, the transferpumps and the L/FUEL XFR and R/ FUEL XFRannunciator circuits are deactivated. The transferpump and annunciator circuits will stay inoperative aslong as the forward fuel cell is empty. Reactivation ofthe transfer pump circuits will occur whenapproximately 18 pounds of fuel enters the forwardfuel cell. As the forward fuel cell is empty atapproximately 193.1 pounds of fuel, if the helicopter is

shut down at, or being refueled to between 193.1 andapproximately 211.1 pounds of total fuel, it is possiblethat up to 18 pounds of fuel may remain in the forwardfuel cell as unusable.

28-6B. Fuel System Components — L/FUEL XFRand R/FUEL XFR Annunciators (S/N 53175and Subsequent)

Activation of either annunciator circuit is dependent onthe relationship between the fuel quantity in theforward fuel tank and the total quantity of the fuelsystem.

The L/FUEL XFR or R/FUEL XFR transferannunciator/Crew Alerting System (CAS) message(407GX) will illuminate when their respective fuelpressure switch senses a decreasing boost pumppressure of 1.5 ±0.5 PSI, provided the conditionsshown in Table 28-1 are met:

With a L/FUEL XFR or R/FUEL XFR pump pressure of5 PSI or greater, the respective left and right fuelpressure switches will open and cause the L/FUELXFR or R/FUEL XFR annunciators/CAS messages(407GX) to go off.

When the fuel signal conditioner detects a forward fueltank quantity of less than 25 pounds and a total fuelsystem quantity of less than 250 pounds, for 10consecutive seconds, L/FUEL XFR or R/FUEL XFRtransfer annunciators/CAS messages will bedeactivated to prevent intermittent light flickering whilethe remaining fuel is transferred from the forward fueltank to the aft fuel tank.

When forward fuel tank depletion is detected by thenumber 3 fuel probe and the low level detector, theinput signals to the fuel signal conditioner areremoved. With the input signals removed, the fuelsignal conditioner utilizes two 360 second time delaysprior to removing the ground to the right and lefttransfer pump relays. This allows the right and lefttransfer pumps to continue running for 360 seconds toensure all the fuel in the forward tank is transferred tothe main fuel tank. The forward fuel cell will be emptywhen approximately 193.1 pounds of total fuel isindicated.

The annunciator and transfer pump circuits will stayinoperative until the fuel system is refueled with an

Table 28-1. Transfer Annunciator/CAS Message (407GX) Activation Table, S/N 53175 and Subsequent

FWD TANK< 25 POUNDS FOR 10 CONSECUTIVE SECONDS

TOTAL FUEL< 250 POUNDS FOR 10 CONSECUTIVE

SECONDS

L/FUEL XFR OR R/FUEL XFR ANNUNCIATOR/CAS MESSAGE (407GX)

ILLUMINATED (AT A DECREASING PRESSURE OF 1.5 ±0.5 PSI)

FALSE FALSE YES

FALSE TRUE YES

TRUE FALSE YES

TRUE TRUE NO

BHT-407-MM-4


appropriate amount of fuel to reactivate the system.Reactivation of the transfer pump circuits will occurwhen approximately 18 pounds of fuel enters theforward fuel cell. As the forward fuel cell is empty atapproximately 193.1 pounds of fuel, if the helicopter isshut down at, or being refueled to between 193.1 andapproximately 211.1 pounds of total fuel, it is possiblethat up to 18 pounds of fuel may remain in the forwardfuel cell as unusable.

28-7. Fuel System Components — Engine FuelFeed System

The engine feed system is made up of two fuel pumpsinstalled on a common sump plate. The fuel pumpsinclude two check valves on the fuel boost pumpoutlets, a tube assembly, a hose assembly, and anorifice to connect the supply from each pump androute it to the main fuel cell external fitting. A fittinginterfaces with the fuel cell, and supplies a port for thefuel pressure transducer and the fuel valve. Hose andtube assemblies connect between the fuel cell fitting,the fuel shutoff valve, and the engine bay firewallunion. Hose assemblies connect between the firewallunion, the airframe fuel filter, and the enginehydromechanical unit (HMU). Two pressure switchesinstalled on the fuel boost pump sump plate are usedto indicate low fuel boost pump pressure. In the eventof low fuel boost pump output pressure, the pressureswitch activates the L/FUEL BOOST and R/FUELBOOST annunciators/Crew Alerting System (CAS)messages (407GX).

The fuel boost pumps run continuously. They movethe fuel from the main cell through the check valves,the various hose assemblies, the fittings, the fuelshutoff valve, and the airframe fuel filter to the engine.The check valves include a relief valve that permitsreverse flow in the event that pressure in the linebetween the check valve and the fuel shutoff valveincreases to a dangerous level due to thermal effects.The fuel shutoff valve includes a similar feature torelieve pressure in the line between the valve and theengine.

The pressure transducer drives the fuel pressureindication on the instrument panel in the flightcompartment. The indication has a red line at 8 and25 PSI. The fuel shutoff valve includes open andclosed position indicator switches, which cause theFUEL VALVE annunciator/CAS message (407GX) tocome on if the position of the fuel shutoff valve is notthe same as the position selected by the pilot. Innormal operation, the annunciator comes on

temporarily when the valve moves from the openposition to the closed position or from the closedposition to the open position. The airframe fuel filtersupplies anti-ice protection to the engine byaccumulating any ice on the fuel filter element. Thefilter incorporates an impending bypass differentialpressure switch, which drives the FUEL FILTERannunciator/CAS message (407GX).

In the event that the filter continues to clog, whichcauses an excessive pressure differential, the filterincludes a bypass valve. The impending bypass switchand bypass valve setting are set to make sure thatthere is sufficient time for the helicopter to be landedand the filter inspected between the time of impendingbypass indication and actual bypass.

The left fuel boost pump and the left fuel transfer pumpare hot-wired to the battery circuit to make sure thatpower continues to be supplied to at least one fuelboost pump and one fuel transfer pump in anycondition. Refer to paragraph 28-7A for information onthe left fuel boost/XFR alternate electrical circuit.

28-7A. Fuel System Components — Left FuelBoost/XFR Alternate Electrical Circuit

In the event that a short circuit or battery hot conditionoccurs in the helicopter and all DC bus power is shutoff, it is desirable to maintain the operation of onetransfer pump and one boost pump.

The BATT switch configures the DC power feed to theleft fuel boost pump and the left fuel transfer pumpbetween the DC bus and the helicopter battery(Figure 28-1A).

In the event the battery switch is positioned to OFFduring helicopter operations, an alternate circuit isprovided to allow operation of the left fuel transfer andleft fuel boost pumps. During this condition, with thefuel valve switch positioned to ON, battery voltage issupplied through the FUEL BOOST/XFR backupcircuit breaker, the fuel valve switch, the batteryswitch, and the left fuel XFR/boost circuit breakerswitch to the left fuel transfer and left fuel boostpumps.

28-8. Fuel System Components — Vent System

The vent system is made up of hoses, tubeassemblies, and fittings. They connect the forward fuelcell and the main fuel cell to a common fitting thatpermits air in and out for fuel burn and refueling.

BHT-407-MM-4


Figure 28-1A. Left Fuel Boost/XFR Alternate Circuit Schematic407_MD_01_0017

TYPICAL

ON

ON

1

2

3

4

5

6 4

5

6

OFF

OFF

15

10

BATTERY

BATTERY RELAYFUEL BOOST/XFR BACKUP

FUEL XFR/BOOST LEFT

LEFTBOOST PUMP

LEFTTRANSFER PUMP

LEFT XFRPUMP RELAY

FUEL SIGNALCONDITIONER

BATTERY SWITCH

28 VDC BUS

FUEL VALVE SWITCH

A2

- +

BHT-407-MM-4


The forward fuel cell is vented through a fitting on itsaft face. A hose assembly connects to the cell andgoes up the interior to the vertical tunnel and ends at aunion in the vertical tunnel. For fumetightness, thehose assembly incorporates an integral silicone rubbersleeve. A rubber boot seals the forward fuel cell cavityand the hose where it attaches to the fuel cell. Tubeassemblies, connected to the vent union, go aft, insideof the roof center beam. A hose assembly, connectedto a fitting installed on the upper right-hand corner ofthe main fuel cell, goes inboard and connects to a teefitting with the vent line from the forward fuel cell.

A hose assembly goes from this tee fitting to the leftside of the fuselage, then to the right side where itconnects to a bulkhead union on the avionics shelf.This is done to minimize the probability of fuel spillagethrough the vent system in the event of a helicopterrollover. A hard tube assembly goes down the rightside to a position close to the belly contour where anon-metallic tube exits the fuselage to vent the fumesoverboard. The end of the non-metallic tube is cut atan angle and faces forward to make sure the forwardfuel cell and the main fuel cell are under a zero orsmall positive pressure.

28-9. Fuel System Components — FuelQuantity Indicating System

The Fuel Quantity Gaging System (FQGS) is acapacitance type system. It is made up of three fuelquantity probes, a fuel quantity harness, a signalconditioner unit, and a fuel quantity indication that isdisplayed on the instrument panel.

One fuel quantity probe is installed in the forward fuelcell and uses three threaded fittings in the cells uppersurface that are attached to the structure. Two fuelquantity probes are installed in the main fuel cell. Themid level fuel quantity probe is installed on the right ofthe boost pump sump plate. The other fuel quantityprobe is flange-installed on a fitting in the uppersurface of the main fuel cell, which is in the hat binarea. The attachment flanges for the forward and midlevel fuel quantity probes are non-symmetrical. Thisensures that the fuel quantity probes can only beinstalled in the correct orientation. The attachmentflange of the aft fuel quantity probe ensures that theprobe can only be installed in the correct orientation.

The fuel quantity harness connects the three fuelquantity probes to the electrical bulkhead connector inthe attachment flange of the aft fuel quantity probe. Anelectrical harness connects this connector to the

signal conditioner unit installed in the aft avionics bay.The signal conditioner unit drives the fuel quantityindication displayed on the instrument panel, whichgives a reading in pounds of fuel. The probes output islinear with the fuel level. All profiling is done in thesignal conditioner unit. The fuel quantity probes havecaps on the lower ends to ensure that in the event of acrash, the fuel quantity probes will crush before thefuel cell punctures.

Compensation for density changes due to the differenttypes of fuel and fuel temperature is done by the signalconditioner unit. The signal conditioner unit gives adiscreet output control to the right transfer pump whena low fuel condition is sensed in the forward tank bythe forward tank probe.

The fuel quantity indication has an analog scale and adigital readout. A FUEL QTY FWD TANK buttonpermits the pilot to see the amount of fuel in theforward fuel cell. During normal operation, theindication provides the total amount of fuel in theforward and main fuel cells. The signal conditioner unithas a Built-in Test (BIT). When the signal conditionerunit detects a fault that would invalidate the fuelquantity displayed, the signal conditioner unit outputsa signal to the fuel quantity indication to blank thedisplay. Three Light Emitting Diodes (LEDs) on theside of the signal conditioner unit indicate the faultdetected. When no faults are detected, the three LEDsare on. Refer to Chapter 95.

28-10. Fuel System Components — Low LevelWarning System

The FUEL LOW annunciator/Crew Alerting System(CAS) message (407GX) circuit is designed to alertthe pilot that the main fuel tank quantity is low.Illumination will occur when approximately100 ±10 pounds of usable fuel remains in the mainfuel cell.

A float type low level switch is used to detect the fuellow condition. The input from the low level detector ispassed through the fuel signal conditioner whichprovides a 13 ±3 second time delay to reduce thepossibility of intermittent annunciator flickering due tofuel sloshing.

In addition, momentary activation (less than2 seconds) of the FUEL LOW annunciator may bevisible on S/N 53000 through 54299 when power isapplied to the helicopter and fuel quantity is greaterthan the required low level activation point. This is a

BHT-407-MM-4


normal occurrence and is a function of fuel signalconditioner power up logic.

28-11. Fuel System Components — Refueling/Defueling

A lightning safe fuel filler cap and adapter is installedin the upper right side of the main fuel cell to permitgravity refueling of the system. The filler cap is hingedto the structure and uses a protruding lever to permitopening and closing.

28-12. Fuel System Components — AuxiliaryFuel Cell Kit

The auxiliary fuel cell kit (BHT-407-II-6) provides anadditional 19 U.S. gallons (71.9 L) of fuel andincreases the total capacity of the fuel system to about150 U.S. gallons (568.0 L). The kit is made up of a fueltank assembly, which can be installed and removed bythe operator, and fixed provisions, which stay in thehelicopter. The auxiliary cell assembly is installed inthe baggage compartment and is designed to beremoved and installed.

The auxiliary fuel cell bladder is installed in a structuralbox, made of composite metal skinned panels. Thebladder is secured at the cell outlet and vent ports byfrangible attachments. The port on the centerline ofthe tank, at the forward end, supplies the fuel cellcavity with drainage and venting. The auxiliary fuel cellis connected to the main fuel cell through two fittingsattached to the bladder and two flexible hoseassemblies connected between the bottom of theauxiliary fuel cell and the two fittings on the aft face ofthe main fuel cell. The fuel is gravity transferredbetween the main fuel cell and the auxiliary fuel cell.The auxiliary fuel cell is vented through a fittingattached to the fuel bladder. A fire resistant hoseassembly connects between the cell and the baggagecompartment ceiling. A hose assembly connects to thetee fitting on the main vent line.

The tank is attached to the aft face of the bulkhead atFS 155.0. The tank is secured on the right side of thebulkhead with two mating brackets that attach to twolugs installed on the bulkhead. The left side of the cellis secured with two fittings that are bolted to thebulkhead. The FQGS signal conditioner unit isprogrammed with two profiles. One profile is for thebasic fuel system and the second profile is for thebasic system plus the auxiliary fuel cell. The signalconditioner unit changes profiles from basic to

auxiliary when the appropriate pin is grounded. Anormally open microswitch, installed on the upper rightside tank bracket, is wired between the signalconditioner unit and a local ground. When the auxiliarytank is installed, the microswitch is pushed in andsupplies an input to the appropriate pin on the signalconditioner unit.

When the tank is not installed, cover plates areinstalled over the access holes in the baggagecompartment floor and the bulkhead fitting in thebaggage compartment ceiling is capped off. The coverplates have dummy connectors to secure the hoseassembly ends.

28-13. Fuel System Components — Fuel CellDraining

The FUEL CELL DRAIN switches provide a means ofdraining fuel from both the forward and aft fuel cellsindividually. The switches are a momentarypushbutton design made up of an outer environmentalseal and an inner switch assembly. They are mountedside by side on the lower right side of the aft fuselage,below and aft of the fuel filler port.

The FUEL VALVE switch must be in the OFF positionto operate either of the fuel cell drain valves. Thisprevents inadvertent operation of the fuel cell drainsduring flight.

With helicopter electrical power provided and theFUEL VALVE switch positioned to OFF, pressing theFUEL CELL DRAIN switches will OPEN the respectivedrain valves allowing fuel to be drained from theforward and main fuel cells.

28-14. Fuel System Components —Miscellaneous

A cover plate is installed over the two auxiliary fuel cellfittings on the aft face of the main fuel cell when theauxiliary fuel tank kit provisions are not installed.Formers are installed between the bottom section ofthe fuel cell and the helicopter structure to createsump areas to help drain residual fuel from the fuelcells.

All attachments of the fuel cell to the structure arefrangible and in the event of a crash, the loads on thefuel cell fittings will be less than the minimum fittingpull-out strength.

BHT-407-MM-4


28-15. Fuel System Components — FlightCompartment Controls and Indications

Fuel system controls (Table 28-2) are located on theinstrument panel, overhead console, and aft lowerright fuselage. The controls consist of a FUEL VALVEswitch, a FUEL BOOST/XFR LEFT switch, a FUELBOOST/XFR RIGHT switch, and two FUEL CELLDRAIN switches.

Table 28-2. Flight Compartment Controls and Indications

ON THE OVERHEAD CONSOLE:

BOOST/XFR OFF/LEFT & OFF/RIGHT Circuit breaker switches to power the left/right boost and transfer pumps as a pair. Left BOOST/XFER circuit breaker also provides power to the signal conditioner unit for the low level switch in the forward tank.

VALVE, QTY & PRESS Applicable circuit breakers for the fuel shutoff valve, fuel quantity indication, and fuel pressure indication, respectively. Fuel quantity circuit breaker also provides power to the signal conditioner unit.

THE FLIGHT COMPARTMENT INDICATIONS THAT FOLLOW ARE GIVEN ON THE CAUTION/WARNING/ADVISORY PANEL/CREW ALERTING SYSTEM (CAS) (407GX):

L/FUEL XFER (amber)R/FUEL XFER (amber)

The output pressure from the transfer pump is low.

FUEL VALVE (amber) The fuel valve is not in the selected position.

FUEL FILTER (amber) The differential pressure across the fuel filter high/filter is in impending bypass or is bypassed.

L/FUEL BOOST (amber)R/FUEL BOOST (amber)

The output pressure from the boost pump is low.

FUEL LOW (amber) There is a total of approximately 100 ±10 pounds of fuel that is not used.

ON THE INSTRUMENT PANEL:

Fuel pressure indication The fuel pressure in PSI measured in the engine fuel feed line upstream from the fuel shutoff valve. Red line at 8 and 25 PSI.

Fuel quantity indication The total quantity of fuel or the quantity of fuel in the forward fuel cell (dependent on TOTAL/FWD switch selection).

Fuel valve switch Guarded switch to open or close the fuel valve.

BHT-407-MM-4


28-16. FUEL SYSTEM — OPERATION

The approved fuel is supplied to the fuel cells(Figure 28-2) through the filler port located on the rightside of the helicopter. When 193.1 pounds of fuelaccumulates in the main fuel cell, the fuel starts togravity transfer through a gravity tube and fills theforward fuel cell. This gravity tube connects to a fittinginstalled on the lower forward face of the main fuelcell. It then connects to a tube that goes along the topof the floor structure to the forward fuel cell where itstarts to fill the forward fuel cell. When the forward fuelcell fills to the level of the standpipe, the main fuel cellcontinues to fill. The head of fuel in the main fuel cellthen causes the forward fuel cell to fill to a totalquantity of 37.6 U.S. gallons (256.0 pounds) (full). Ifthe auxiliary fuel cell is installed, it fills at the same rateas the main fuel cell through two openings installed onthe lower aft wall of the main fuel cell and the bottomof the auxiliary fuel cell.

The normal operation of the fuel system starts whenthe battery switch is set to the ON position or when 28VDC external power is connected to the helicopter.The sample fuel is drained from the forward and mainfuel cells to identify any water or contamination thatmay be present. The sump drain circuit is only activewhen the fuel valve is in the OFF position. The twosump drain pushbuttons, installed on the lower aft rightfuselage, are pushed one at a time to open therespective sump drain solenoids. The solenoids areinstalled on the fuel pump attachment plates in theforward and main fuel cells.

The fuel quantity is indicated on the fuel quantitygauge or the Engine Indicating System (EIS) (407GX).The fuel quantity indicates the total fuel in both theforward and main fuel cells. When the auxiliary fuelcell kit is installed, the fuel quantity indication showsthe total fuel quantity in the three fuel cells. Theforward fuel cell quantity is indicated when the forwardfuel cell pushbutton indication is pushed in.

If the battery switch is set to the OFF position duringflight, the DC power supply from the battery to the leftfuel transfer and the left fuel boost pump is fed throughthe fuel valve switch (when in the ON position) andthrough the battery switch (paragraph 28-7A). If thehelicopter is parked with the battery switch set to the

OFF position, the fuel valve switch set to the ONposition, and the left FUEL BOOST/XFER switch setto the ON position, the left boost /transfer pumps willoperate.

The fuel boost/transfer pump system is made up oftwo pump assemblies. One is installed on the base ofthe forward fuel cell (transfer pump). The second oneis installed on the base of the main fuel cell (boostpump). The pump assemblies are made up of fouridentical, interchangeable, canister type pumps. Theleft transfer pump and the left boost pump are turnedon together when the FUEL BOOST/XFR LEFT switchis set to the LEFT position. The right transfer pumpand right boost pump are turned on together when theFUEL BOOST/XFR RIGHT switch is set to the RIGHTposition.

The fuel from the forward fuel cell is transferred to themain fuel cell by two transfer pumps installed on asump plate assembly located in the base of theforward fuel cell. The fuel is pumped through a fuelhose to a fitting at the lower centerline of the forwardfuel cell. A flex hose carries the fuel under pressurealong the top of the floor structure to a fitting on themain fuel cell, where the fuel enters through a fittingand a transfer tube and spills into the main fuel cell.

The fuel from the main fuel cell is supplied to theengine through two boost pumps located at the baseof the main fuel cell on the sump plate. Similar to theforward fuel cell, fuel flows through the check valves toa common tee fitting, then through a hose to a fittinglocated on the top right of the main fuel cell. The fuelleaves the main fuel cell and connects to the fuelshutoff valve, located adjacent to the hat rack. Thepressure transducer, installed between the main fuelcell fitting and the fuel shutoff valve, supplies theelectrical signal to the pressure gauge, installed on theinstrument panel.

When the fuel goes through the fuel shutoff valve, afuel hose routed through the airframe structuresupplies fuel through a fitting to the airframe fuel filter,installed on the right side of the forward enginefirewall. When the fuel goes through the airframe fuelfilter, the fuel is supplied by a fuel hose to the enginedriven pump.

BHT-407-MM-4

28-00-00

ECCN EAR99

Figure 28-2. Fuel System Schematic407MM_28_0003

FUELPRESS

FUEL FILTER(AMBER)

FUEL VALVE(AMBER)

FUEL VALVE SWITCH

FIREWALL

DRAINHOSE

MANUAL DRAINVALVE

ENGINE

AIRFRAMEFUEL FILTER

VENT LINE

FUELQTYLBS

L/FUEL BOOST(AMBER)

R/FUEL BOOST(AMBER)

FUEL LOW(AMBER)

R/FUEL XFR(AMBER)

L/FUEL XFR(AMBER)

FUEL SIGNALCONDITIONER

QTY PROBE (3 PL)CHECK VALVEWITH THERMALRELIEF

TRANSFERPUMP DUAL

ELECTRICSUMP DRAIN

PRESSURESWITCH

LOW LEVELDETECTORSWITCH

TYPICAL

LOW LEVELSWITCH

ELECTRICSUMP DRAIN

INTERCONNECTSTANDPIPE

TRANSFER LINE

TRANSFERBLEED

FWD FUELCELL AFT FUEL

CELL

AUX FUEL TANKKIT (REF)

OVERBOARDVENT

CHECK VALVEWITH THERMALRELIEF

DUAL BOOSTPUMPS

ENGINE FEEDLINE

FILLER CAP

PRESSURETRANSDUCER

SHUT OFF VALVEWITH THERMALRELIEF

16 FEB 2012 Rev. 34 Page 14A

BHT-407-MM-4

ECCN EAR99

28-00-00

During normal operation, the fuel empties from themain fuel cell through the boost pumps to a levelwhere the gravity transfer standpipe opening in themain fuel cell will no longer be transferring fuel to theforward fuel cell. At this point, fuel pumped by thetransfer pumps into the aft tank will remain until burntby the engine. Since the fuel level is below thestandpipe opening, it will not feed by gravity back intothe forward tank. When the fuel level in the forwardtank is reduced, the low level will be detected by theforward fuel quantity probe and the low level detectorand sent to the fuel signal conditioner.

When the forward fuel cell is nearing depletion, thesignal conditioner uses time delays to control thetransfer pumps and annunciators/CAS messages(407GX). The time delay allows continued operation ofthe transfer pumps to ensure all of the fuel in theforward cell is transferred to the main fuel tank. Theforward fuel cell will be empty when approximately193.1 pounds of total fuel is indicated.

Due to differing operation of the left and right fueltransfer circuits on helicopters S/N 53000 through53174 versus S/N 53175 and subsequent, refer toparagraph 28-6A, paragraph 28-6B, or Chapter 95 andChapter 96 for specific information.

As the fuel level continues to drop, the main fuel cellfuel quantity indicating system gives an accurate fuellevel signal to the fuel quantity indication circuitthrough the aft fuel quantity probe and the mid levelfuel quantity probe in the main fuel cell (Chapter 95).The FUEL LOW annunciator comes on when100 ±10 pounds of fuel is left in the main fuel cell.

28-17. FUEL SYSTEM — HANDLING ANDSAFETY PRECAUTIONS

WARNING

BE VERY CAREFUL WHEN YOU FUELOR DEFUEL THE HELICOPTER. JETFUEL IS EXTREMELY FLAMMABLE. THEFUEL FUMES AND GASSES CAN IGNITEWITH STATIC ELECTRICITY, FRICTIONSPARKS, HOT EXHAUST P IPES,LIGHTED CIGARETTES, ELECTRICALDEVICES, OR S IMILAR IGNIT IONSOURCES. DO NOT SMOKE AROUNDTHE HELICOPTER.

1. When you are fuelling or defueling the helicopter,make sure it is in an area where the risk of fire isdecreased.

2. Make sure the helicopter is grounded before youfuel or defuel.

CAUTION

MAKE SURE THAT THE FUEL CELL IS ATROOM TEMPERATURE BEFORE YOUFOLD OR UNFOLD IT. WHEN YOUREMOVE OR INSTALL A FUEL CELL,HANDLE IT WITH CARE. AFTER YOUREMOVE THE FUEL CELL, MAKE SURETHAT PROTECTIVE COVERS AREINSTALLED ON ALL THE PORTS TOPREVENT THE ENTRY OF UNWANTEDMATERIAL.

3. Make sure you take care when you remove orinstall a fuel cell. Do not attempt to remove or install acold fuel cell.

4. Do not use sharp tools to remove or install a fuelcell.

5. Keep the fuel cell folded until it is installed in thefuel cell compartment.

6. If a fuel cell is stored without turbine fuel (C-003)for a long period of time, moisten a clean cloth withturbine fuel (C-003) and rub the fuel cell liner toprevent it from becoming dry.

Refer to BHT-ALL-SPM for specifications.

MATERIALS REQUIRED

NUMBER NOMENCLATURE

C-003 Turbine Fuel

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ECCN EAR99

28-18. FUEL SYSTEM — TROUBLESHOOTING

For the troubleshooting procedures of the fuel systemelectrical system, refer to Chapter 96.

28-19. FUEL SYSTEM — PRESSURE TEST

1. On the collective control stick, turn the throttle tothe OFF position.

2. Close the fuel filler cap.

NOTE

The FUEL VALVE annunciator/CrewAlerting System (CAS) message (407GX)comes on when the valve is in transit.

3. On the instrument panel, set the FUEL VALVEOFF/ON switch to ON. Make sure that the FUELVALVE annunciator/CAS message (407GX) comes onand then goes off.

CAUTION

DO NOT PRESSURIZE THE FUELSYSTEM WITH MORE THAN 1.00 PSI(6.89 kPa) OF AIR PRESSURE. IF YOUDO NOT OBEY THIS, YOU CAN DAMAGETHE FUEL SYSTEM OR THE AIRFRAMESTRUCTURE.

NOTE

Use low pressure dry filtered air to pressuretest the fuel system. Make sure that youuse a low pressure gauge and a shutoffvalve.

4. Connect the dry filtered air source to the fuelsystem vent outlet on the lower right side of the aftfuselage.

5. Slowly apply dry filtered air to the fuel system untilthe pressure gauge reads between 0.50 and 1.00 PSI(3.45 and 6.89 kPa). Close the valve on the pressuresource.

6. Allow temperature stabilization for a minimum of30 minutes.

7. After stabilization, make sure that the fuel systemholds the air pressure for a minimum of 30 minutes.

8. If the fuel system does not hold the air pressure,find the leaks with detergent (C-355). Repair all leaksand repeat the pressure test.

9. Close the air pressure source and let the airpressure bleed off as the test equipment is removed.

10. Remove the test equipment from the fuel systemvent.

11. On the center instrument panel, set the FUELVALVE switch to the OFF position.

28-20. FUEL SYSTEM — OPERATIONAL CHECK

This inspection should be accomplished immediatelyafter fuel system maintenance and/or componentchange/removal, at an adequate maintenance facility.

When maintenance or component change/removal isconducted below the top fitting of the aft fuel cellimmediately following fuel system maintenance and/ormajor component change/removal (boost pump/transfer pump assembly, check valves, fuel lines orhoses), ground run the helicopter and check for air andfuel leaks and for proper operation as follows:


MATERIALS REQUIRED

NUMBER NOMENCLATURE

C-355 Detergent

16 FEB 2012 Rev. 34 Page 14C

BHT-407-MM-4

ECCN EAR99

28-00-00

NOTE

Installation and removal of a fuel boostpump cartridge, fuel quantity probe, or fueldrain valve does not require this inspection.

NOTE

If fuel system maintenance and/orcomponent change/removal is performed at

a site remote from an adequatemaintenance facility, accomplish step 3,step 4, step 5, and step 10, or step 7 andstep 10, as applicable, prior to flight. Onreturn to an adequate maintenance facility,but not to exceed 10 flight hours,accomplish the entire inspection.

1. Make sure all fuel has been drained from the aftand forward fuel cells.

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BHT-407-MM-4

28-00-0010 DEC 2012 Rev. 35 Page 15Export Classification C, ECCN EAR99

2. Service the fuel cell with 10 gallons (37.9 L) ofturbine fuel (C-003).

3. Perform the normal engine starting and run-upchecks (BHT-407-FM-1 or BHT-407-FM-2).

NOTE

If a flameout or power loss occurs, refer tostep 10.

4. Set the throttle to full open and operate theengine at 100% N2 for a minimum of 2 minutes withboth fuel boost pumps off.

5. Perform the normal engine shutdown(BHT-407-FM-1 or BHT-407-FM-2).

6. Set the fuel quantity switch to the forward positionto make sure that the fuel transfer from the aft to theforward cell has not occurred.

7. When maintenance and/or component change isconducted above the top fitting of the fuel cell,immediately after the fuel system maintenance and/orcomponent change/removal (fuel pressure transducer,fuel valve, scheduled fuel component change/removal,fuel lines, or hose), ground run the helicopter andcheck for air or fuel leaks and for proper operation inthe steps that follow.

8. Perform a normal engine start and run-up checks.

9. Set the throttle to full open and operate theengine at 100% N2 for a minimum of 2 minutes withboth fuel pumps off. If a flameout or power loss occurs,refer to step 10.

10. If a flameout or power loss occurs, air is enteringthe helicopter or engine fuel system, or an enginepneumatic leak exists. Correct the malfunction beforeyou start flight operations.

11. Make sure the fuel boost pump, check valve, andfuel shutoff valve operate correctly.

12. Make sure all the hoses and lines are serviceableand do not have cracked flares and that the "B" nutsare correctly tightened.

13. Purge the air from the fuel system and do apneumatic leak check. Refer to the Rolls-Royce250-C47B Series Operation and Maintenance Manual,Publication CSP 210001.

28-21. FORWARD AND MAIN FUEL CELL —INSPECTION

1. Defuel the forward and main fuel cell to getaccess to the components (Chapter 12).

2. Remove the fuel transfer pump assembly(paragraph 28-33).

3. Examine the fuel transfer pump assembly(paragraph 28-34).

4. Remove the fuel transfer pump check valves(paragraph 28-41).

5. Examine the fuel transfer pump check valves(paragraph 28-42).

6. Install the fuel transfer pump check valves(paragraph 28-43).

7. Remove the fuel boost pump assembly(paragraph 28-51).

8. Examine the fuel boost pump assembly(paragraph 28-52).

9. Remove the fuel boost pump check valves(paragraph 28-59).

10. Examine the fuel boost pump check valve(paragraph 28-60).

11. Install the fuel boost pump check valve(paragraph 28-61).

12. Examine the forward fuel cell (paragraph 28-25).

13. Examine the main fuel cell (paragraph 28-29).

14. Examine the fuel system shutoff valve andcomponents for condition, leaks, and security.

15. Install the fuel transfer pump assembly(paragraph 28-35).

16. Install the fuel boost pump assembly(paragraph 28-53).

17. Apply external DC power to the helicopter(Chapter 96).

BHT-407-MM-4


18. Make sure the FUEL LOW annunciator/CrewAlerting System (CAS) message (407GX) comes on.

19. Fill the main fuel cell with turbine fuel (C-003)until the fuel gauge reads approximately 98 pounds offuel.

20. Make sure the FUEL LOW annunciator/CASmessage (407GX) goes off (Chapter 12 andChapter 96).

21. Do an operational check of the fuel system(paragraph 28-20).

28-22. FUEL STORAGE

The fuel storage is made up of a forward fuel cell anda main fuel cell.

28-23. FORWARD FUEL CELL

For a description of the forward fuel cell, refer toparagraph 28-3.

28-24. Forward Fuel Cell — Removal

CAUTION

MAKE SURE YOU INSTALL CAPS AND/OR PLUGS (C-428) ON ALL OF THEOPENED LINES AND PORTS OF THEFUEL SYSTEM. THIS PREVENTSCONTAMINATION OF THE SYSTEM.

1. Make sure the helicopter is grounded.

2. Remove the aft facing left-hand and right-handpassenger seat cushions and the seat backs(Chapter 25).

3. Defuel the forward and main fuel cell(Chapter 12).

4. Drain the forward and main fuel cell (Chapter 12).

5. Disconnect the battery from the helicopter(Chapter 96).


7. Purge the forward fuel cell (Chapter 12).

8. Remove the forward fuel cell fuel quantity probefrom the forward fuel cell (paragraph 28-87).

9. Remove the forward section of the fuel cellinterconnect tube (paragraph 28-69, step 6, and step 8through step 12).

10. Remove the seven screws (1, Figure 28-3) andwashers (2) from the retainer (3).

11. Remove the retainer (3) and the fuel cell ventboot (4) from the forward fuel cell (5).

12. Remove the two bolts (6) and washers (7) fromthe retainer (8).

13. Remove the retainer (8) and the two spacers (9)from the forward fuel cell (5).

14. Remove the fuel cell vent (10) and the packing(11) from the forward fuel cell (5). Discard the packing.

15. Remove the two fuel cell support screws (12) andwashers (13) from the left-hand seat panel (14) andthe right-hand seat panel (15).

16. Remove the 15 screws (25) from the left-handand right-hand seat strips (26).

17. Remove the 25 screws (16) and washers (17)from the left-hand seat panel (14).

18. Remove the left-hand seat panel (14) from thefuel cell compartment.

19. Remove the 26 screws (18) and washers (19)from the right-hand seat panel (15).

20. Remove the right-hand seat panel (15) from thefuel cell compartment.


MATERIALS REQUIRED

NUMBER NOMENCLATURE

C-428 Caps and/or Plugs

(DD

ago

E

Bell Helicopter TEXTRON BHT-407-MM-4

1. Screw2. Washer3. Retainer4. Fuel cell vent boot5. Forward fuel cell6. Bolt7. Washer8. Retainer9. Spacer

10. Fuel cell vent11. Packing12. Screw13. Washer14. Left seat panel15. Right seat panel16. Screw17. Washer18. Screw19. Washer20. Screw21. Washer22. Intercostal cover23. Screw24. Washer25. Screw26. Strip

:

ZL Boot is removed from vent

Figure 28-3. Forward fuel cell

NOTE

28-00-00Rev. 4 Page 17

BHT-407-MM-4

28-00-00Page 18 Rev. 4

21. Remove the three screws (20) and washers (21) from the intercostal cover (22).

22. Remove the 24 screws (23) and washers (24) from the intercostal cover (22).

23. Remove the intercostal cover (22) from the intercostal assembly.

MAKE SURE THAT THE FUEL CELL IS AT ROOM TEMPERATURE BEFORE YOU FOLD OR UNFOLD IT. WHEN YOU REMOVE OR INSTALL THE FUEL CELL, HANDLE IT WITH CARE. AFTER YOU REMOVE THE FUEL CELL, MAKE SURE THAT PROTECTIVE COVERS ARE INSTALLED ON ALL OF THE PORTS, TO PREVENT THE ENTRY OF UNWANTED MATERIALS.

24. Collapse the forward fuel cell (5). Remove the fuel cell from the fuel cell compartment.

28-25. Forward fuel cell — Inspection, cleaning and repair

1. Examine the internal and the external areas of the fuselage under the forward fuel cell for signs of fuel leaks.

2. Examine the forward fuel cell for signs of cracks, damage to attachment faces and general fuel cell condition.

3. Examine the fuel cell interconnect tube for signs of leaks, damage and security.

4. Examine the forward fuel cell vent for signs of leaks, damage to the fumetight boot, damage to tubes and fittings.

5. Examine the interior of the forward fuel cell for signs of fungus.

DO NOT USE SOAPS OR STRONG DETERGENTS TO CLEAN THE INTERIOR OF THE FUEL CELL. SOME SOAPS OR DETERGENTS CAN CAUSE DAMAGE TO THE FUEL CELL. SOAPS CAN REACT WITH TURBINE FUEL (C-003 , BHT-ALL-SPM) AND CAUSE CONTAMINATION IN THE FUEL FILTER.

6. Remove all of the fungus growth with a soft scrub brush and warm water. Rub the inside of the fuel cell with a clean cloth and methyl alcohol (C-302, BHT-ALL-SPM).

NOTE

You cannot repair cuts or tears that are longer than 1.0 inch (25 mm), that are in a radius, or that are in the attachment plates. If the fuel cell damage is beyond the serviceable limits of the vendor, the fuel cell must be returned to the vendor for repairs.

7. Examine the fuel cell for cuts or tears.

8. Repair cuts or tears with the repair kit from the vendor of the fuel cell.

28-26. Forward fuel cell — Installation

MAKE SURE THAT YOU REMOVE THE CAPS AND/OR PLUGS (C-428, BHT-ALL-SPM) FROM ALL OF THE OPEN LINES AND PORTS OF THE FUEL SYSTEM. THIS PREVENTS CONTAMINATION OF THE SYSTEM.

1. Examine the fuel cell compartment for unwanted objects. Make sure all sharp edges and rivet heads are covered with tape (C-453, BHT-ALL-SPM).

2. Remove the caps and/or plugs (C-428, BHT-ALL-SPM) from the lines and the ports of the fuel system.

BHT-407-MM-4

28-00-00Rev. 4 Page 19

3. Apply talcum powder (C-408, BHT-ALL-SPM) to the inside of the fuel cell liner in the forward fuel cell compartment.

MAKE SURE THAT THE FUEL CELL IS AT ROOM TEMPERATURE BEFORE YOU FOLD OR UNFOLD IT. WHEN YOU REMOVE OR INSTALL THE FUEL CELL, HANDLE IT WITH CARE. AFTER YOU REMOVE THE FUEL CELL, MAKE SURE THAT THE PROTECTIVE COVERS ARE INSTALLED ON ALL THE PORTS, TO PREVENT THE ENTRY OF UNWANTED MATERIAL.

4. Place the forward fuel cell (5, Figure 28-3) in the forward fuel cell compartment.

MAKE SURE YOU REMOVE ALL THE SEALANT THAT REMAINS ON THE FAYING SURFACE OF THE INTERCOSTAL COVER AND FROM THE FORWARD FUEL CELL COMPARTMENT.

5. Remove all the sealant that remains on the faying surfaces of the intercostal cover and from the forward fuel cell compartment.

6. Apply a layer of sealing compound (C-328, BHT-ALL-SPM) on the faying surfaces of the intercostal cover (22) and the intercostal assembly.

7. Install the intercostal cover (22) and safety the panel with 24 washers (24) and screws (23).

8. Attach the centre section of the forward fuel cell to the intercostal cover (22) with three washers (21) and screws (20).

9. Install the forward fuel quantity probe in the forward fuel cell (Paragraph 28-89).

10. Apply a thin layer of turbine fuel (C-003, BHT-ALL-SPM) on the packing (11).

11. Install the packing (11) on the fuel cell vent (10).

12. Align the two spacers (9) between the forward fuel cell (5) and the fuel cell vent (10). Install the fuel cell vent in the forward fuel cell (5).

13. Attach the fuel cell vent (10) to the forward fuel cell (5) with the retainer (8), the two washers (7) and bolts (6).

14. Align the fuel cell vent boot (4) and the retainer (3) on the forward fuel cell (5).

15. Attach the retainer (3) to the forward fuel cell (5) with the seven washers (2) and screws (1).

16. Install the forward section of the fuel cell interconnect tube (Paragraph 28-71, Steps 5, 6, 7, 22, 23, 24 and 29).

17. Apply a layer of sealing compound (C-328, BHT-ALL-SPM) on the faying surfaces of the left hand seat panel (14) and the left hand side of the forward fuel cell compartment.

18. Install the left hand seat panel (14) on the fuel cell compartment and attach the panel with 25 washers (17) and screws (16).

19. Install the right hand seat panel (15) on the fuel cell compartment and attach the panel with 26 washers (19) and 26 screws (18).

20. Install the left hand and right hand seat strips (26) and safety each strip with the 15 screws (25).

21. Attach the left hand section of the forward fuel cell to the left hand seat panel (14) and the right hand section to the right hand seat panel (15) with the two washers (13) and the two screws (12).

22. Install the fuel transfer pump assembly (Paragraph 28-35).

23. Install the aft facing left hand and right hand passenger seats (Chapter 25).

BHT-407-MM-4

28-00-00Page 20 Rev. 4

24. Connect the battery power to the helicopter (Chapter 96).

25. Fill the fuel system with turbine fuel (C-003, BHT-ALL-SPM) (Chapter 12) and examine for leaks.

28-27. MAIN FUEL CELL

For the description of the main fuel cell, refer to Paragraph 28-3.

28-28. Main fuel cell — Removal

MAKE SURE THAT YOU INSTALL CAPS AND/OR PLUGS (C-428, BHT-ALL-SPM) ON ALL OF THE OPEN LINES AND PORTS OF THE FUEL SYSTEM. THIS PREVENTS CONTAMINATION OF THE SYSTEM.


2. Defuel the forward and main fuel cell (7, Figure 28-4) (Chapter 12).

3. Drain the forward fuel cell and the main fuel cell (7) (Chapter 12).

4. Disconnect the battery power from the helicopter (Chapter 96).

5. Remove the hat bin panel assembly (Chapter 25).

6. Remove the forward facing passenger seat cushions and seat backs (Chapter 25).

7. Remove the screws and washers from the main fuel cell access panel. Remove the panel from the fuel cell compartment.

8. Remove the fuel boost pump assembly (Paragraph 28-51).

9. Purge the main fuel cell (7) (Chapter 12).

10. Remove the aft section of the fuel cell interconnect (Paragraph 28-69, Steps 8 and 13 through 20).

11. Remove the mid level fuel quantity probe (Paragraph 28-99).

12. Remove the aft fuel quantity probe (Paragraph 28-95).

13. Remove the 17 screws and washers from the fuel shutoff valve access panel.

14. Remove the fuel shutoff valve access panel from the structure.

15. Remove the main fuel cell vent line (1) from the vent fitting (2).

16. Remove the four screws (3) and the four washers (4) from the vent fitting (2).

17. Remove the vent fitting (2) from the flange (5). Remove the flange with the packing (6) from the main fuel cell (7). Discard the packing.

18. Remove the engine fuel feed line (8) from the fuel outlet fitting (9).

19. Remove the jam nut (10) and the washer (11) from the fuel outlet fitting (9).

20. Remove the fuel outlet fitting (9) and the packing (12) from the main fuel cell (7). Discard the packing.

21. Remove the two screws (13) and the two washers (14) from the fuel cap hinge.

22. Remove the 10 screws (15) and the 10 washers (16) from the fuel cap retainer (17).

23. Remove the retainer (17), the cap and adapter (30), the seal ( 18) and the packing (19) from the main fuel cell (7). Discard the seal and the packing.

24. Remove the two bolts (20) and the two washers (21) from the retainer (22). Remove the retainer from the main fuel cell (7).

25. Remove the five screws (23) and the five washers (24) from the main fuel cell (7).

26. Remove the panel that mounts the Automatic Direction Finder (ADF) antenna (Chapter 97).

BHT-407-MM-4


Figure 28-4. Main Fuel Cell

NO OBJECT BEYOND THIS POINT 407MM_28_0007

Fuel cell vent lineVent fittingScrewWasherFlangePackingMain fuel cellFuel feed lineFuel outlet fittingJam nutWasherPackingScrewWasherScrew

1.2.3.4.5.6.7.8.9.

10.11.12.13.14.15.

WasherFuel cap retainerSealPackingBoltWasherRetainerScrewWasherBoltWasherRetainerCover platePackingCap and adapter

16.17.18.19.20.21.22.23.24.25.26.27.28.29.30.

8

9

12

11

10

20

213

4

2

6

522

DETAIL A

1

SEE DETAIL A1 15

16

18

3017

14131

19

7

23

24

2526

27

2829

2

50 TO 75 IN-LBS(5.65 TO 8.47 Nm)1

40 IN-LBS MAX(4.52 Nm MAX)

2

BHT-407-MM-4

28-00-00Page 22 Rev. 4

27. Remove the four bolts (25) and the four washers (26) from the two retainers (27) on the left hand and right hand auxiliary fuel cell attachment plates.

28. Remove the two retainers (27) from the left hand and right hand auxiliary fuel cell attachment plates.

29. Remove the cover plate (28) from the left hand and right hand auxiliary fuel cell attachment plate.

30. Remove and discard the packing (29) from the recess in both the left hand and right hand auxiliary fuel cell attachment plate.

MAKE SURE THAT THE FUEL CELL IS AT ROOM TEMPERATURE BEFORE YOU FOLD OR UNFOLD IT. WHEN YOU REMOVE OR INSTALL THE FUEL CELL, HANDLE IT WITH CARE. AFTER YOU REMOVE THE FUEL CELL, MAKE SURE THAT THE PROTECTIVE COVERS ARE INSTALLED ON THE OPEN PORTS, TO PREVENT THE ENTRY OF UNWANTED MATERIAL.

31. Fold the main fuel cell (7). Remove it from the fuel cell compartment.

28-29. Main fuel cell — Inspection, cleaning and repair

1. Examine the internal and the external areas of the fuselage under the main fuel cell for signs of fuel leaks.

2. Examine the main fuel cell for signs of cracks, damage to attachment faces and general condition of the fuel cell.

3. Examine the fuel cell interconnect tube for signs of leaks, damage and security.

4. Examine the main fuel cell vent for signs of leaks, damage to tubes and fittings.

5. Examine the interior of the main fuel cell for signs of fungus.

DO NOT USE SOAPS OR STRONG DETERGENTS TO CLEAN THE INTERIOR OF THE FUEL CELL. SOME SOAPS OR DETERGENTS CAN CAUSE DAMAGE TO THE FUEL CELL. SOAPS CAN REACT WITH TURBINE FUEL (C-003 , BHT-ALL-SPM) AND CAUSE CONTAMINATION IN THE FUEL FILTER.

6. Remove all the fungus growth with a soft scrub brush and warm water. Wipe the inner liner with a clean cloth moist with methyl alcohol (C-302, BHT-ALL-SPM).

NOTE

You cannot repair cuts or tears that are longer than 1.0 inch (25 mm), that are in a radius, or that are in the attachment plates. If the main fuel cell damage is beyond the serviceable limits of the vendor, the fuel cell must be returned to the vendor for repairs.

7. Examine the main fuel cell for cuts or tears.

8. Repair cuts or tears with the repair kit from the vendor of the fuel cell.

28-30. Main fuel cell — Installation

MAKE SURE YOU REMOVE ALL THE CAPS AND/OR PLUGS (C-428, BHT-ALL-SPM) FROM ALL THE OPEN LINES AND PORTS OF THE FUEL SYSTEM.

1. Examine the main fuel cell for unwanted objects. Make sure sharp edges and rivet heads are covered with tape (C-453, BHT-ALL-SPM).

2. Apply talcum powder (C-408, BHT-ALL-SPM) to the inside of the main fuel cell compartment.

BHT-407-MM-4

28-00-00Rev. 4 Page 23

MAKE SURE THAT THE FUEL CELL IS AT ROOM TEMPERATURE BEFORE YOU FOLD OR UNFOLD IT. WHEN YOU REMOVE OR INSTALL THE FUEL CELL, HANDLE IT WITH CARE.

3. Place the main fuel cell (7, Figure 28-4) in the main fuel cell compartment.

4. Attach the main fuel cell (7) to the main fuel cell compartment with the five washers (24) and five screws (23).

5. Apply a light layer of turbine fuel (C-003, BHT-ALL-SPM) on the two packings (29). Install the packings in the recess of both the left hand and right hand auxiliary fuel cell attachment plates.

6. Install the two cover plates (28) on the left hand and the right hand auxiliary fuel cell attachment plate.

7. Safety the left hand and the right hand auxiliary fuel cell attachment plates to the cover plates (28) with the two retainers (27), the four washers (26) and the four bolts (25). Tighten the four bolts (25) on the left hand and the right hand auxiliary fuel cell attachment plates.

8. Install the retainer (22) on the main fuel cell (7) and secure with the two washers (21) and bolts (20). Tighten the two bolts (20) .

9. Apply a thin layer of turbine fuel (C-003, BHT-ALL-SPM) on the packing (19) and install the packing in the recess of the main fuel cell attachment plate.

10. Install the seal (18) on the retainer (17) and secure the retainer to the main fuel cell with the 10 washers (16) and the screws (15). Tighten the screws (15) .

11. Install the fuel cap and adapter assembly (30) on the retainer (17) and secure with the two washers (14) and the screws (13). Tighten the screws (13) .

12. Apply a light layer of turbine fuel (C-003, BHT-ALL-SPM) on the packing (12). Install the packing on

the fuel outlet fitting (9) and install the fitting in the fuel outlet fitting port.

13. Secure the fuel outlet fitting (9) with the washer (11) and the jam nut (10).

14. Install the engine fuel feed line (8) on the fuel outlet fitting (9).

15. Apply a light layer of turbine fuel (C-003, BHT-ALL-SPM) on the packing (6) and install the packing in the recess of the main fuel cell (7).

16. Install the flange (5) and the vent fitting (2) on the main fuel cell (7) and secure with the four washers (4) and the four screws (3).

17. Install the vent line (1) on the vent fitting (2).

18. Install the aft fuel quantity probe (Paragraph 28-97).

19. Install the mid level fuel quantity probe (Paragraph 28-101).

20. Install the aft section of the fuel cell interconnect (Paragraph 28-71, Steps 8 through 12, 18 through 20, and 27 through 29).

21. Install the fuel boost pump assembly (Paragraph 28-53).

22. Install the main fuel cell access panel on the fuel cell compartment and secure with the washers and the screws.

23. Install the hat bin assembly panel (Chapter 25).

24. Install the forward facing seat cushions and seat backs (Chapter 25).

25. Connect the battery power to the helicopter (Chapter 96).

26. Fill the fuel system with turbine fuel (C-003, BHT-ALL-SPM) (Chapter 12) and examine for leaks.

28-31. FUEL DISTRIBUTION

The fuel distribution system is divided into three sections. The first section is made up of the

T

T

T

BHT-407-MM-4

28-00-00Page 24 Rev. 26 23 DEC 2009 ECCN EAR99

components installed in the forward fuel cell. Thesecond section is made up of the fuel cell interconnecttube and the components installed in the main fuelcell. The third section is made up of componentsbetween the main fuel cell and the forward firewall. Forthe description of the components, refer to paragraph28-1.

28-32. FUEL TRANSFER PUMP ASSEMBLY

For the description of the fuel transfer pump assembly,refer to paragraph 28-6.

28-33. Fuel Transfer Pump Assembly — Removal


2. Defuel the forward fuel cell and the main fuel cell(Chapter 12).

3. Drain the forward fuel cell and the main fuel cell(Chapter 12).

4. Disconnect the helicopter battery (Chapter 96).

5. Remove the 12 screws and 12 washers andremove the fuel transfer pump assembly cover fromthe bottom of the fuselage.

6. Using extraction tool M81714/69-01, disconnectthe electrical connector 1P12 (1, Figure 28-5) from theconnector 1J12 (2).

7. Using extraction tool M81714/69-01, disconnectthe electrical connector 1P13 (3) from the electricalconnector 1J13 (4).

8. Remove the screw (5) from the clamp (6) andremove the electrical harness (7) from the pump (8).

9. Remove the screw (9) and washer (10) from theretainer (14).


11. Remove the retainer (14) and two washers (11and 15) from the pump (8).

12. Remove the 24 bolts (16, 22, and 24) washers(17, 23, and 25) from the pump (8).

13. Remove the pump (8) from the forward fuel cellassembly (18) and disconnect the hose assembly (19)from the tee (20).

CAUTION

MAKE SURE THAT YOU INSTALL THECAPS AND/OR PLUGS (C-428) ON ALLTHE OPEN LINES AND PORTS OF THEFUEL SYSTEM. THIS PREVENTSCONTAMINATION OF THE SYSTEM.

14. Install the caps and/or plugs (C-428) on all openlines and the open port of the forward fuel cell.

15. Remove the packing (21) from the pump (8).Discard packing.

28-34. Fuel Transfer Pump Assembly —Inspection

1. Examine the fuel transfer pump assembly forcorrosion.

2. Examine the fuel transfer pump electrical harnessfor signs of chafing, cracked wires, and damage to theelectrical connectors.

3. Examine the mating surface of the forward fuelcell and the fuel transfer pump assembly for signs ofleaks.

SPECIAL TOOLS REQUIRED

NUMBER NOMENCLATURE

M81714/69-01 Extraction Tool


MATERIALS REQUIRED

NUMBER NOMENCLATURE


BHT-407-MM-4


Figure 28-5. Fuel Transfer Pump AssemblyNO OBJECT BEYOND THIS POINT 407MM_28_0055_c01

6. Clamp5. Screw

7. Harness

9. Screw

11. Washer

8. Pump

10. Washer

16. Bolt17. Washer

15. Washer14. Retainer13. Washer

20. Tee21. Packing

12. Screw

19. Hose assembly18. Forward fuel cell assembly10

11

4

3

12

13

56

15

7

3.

14

4.

16

2

11.2.

22

20

19

21

8

ConnectorConnector

ConnectorConnector

18

9

24. Bolt25. Washer

23. Washer22. Bolt

B

VIEW B17

2324 25

50 TO 70 IN-LBS MAX(5.65 TO 7.91 Nm MAX)

DETAIL A

SEE DETAIL A

BHT-407-MM-4

28-00-00Page 26 Rev. 35 10 DEC 2012 Export Classification C, ECCN EAR99

4. Examine the fuel transfer pump assembly foreccentric bolt holes.

5. Examine the bolt hole threads of the forward fuelcell for signs of damage.

28-35. Fuel Transfer Pump Assembly —Installation

1. Remove the caps and/or plugs from the forwardfuel cell open port and the hose assembly (19,Figure 28-5).

2. Examine the internal part of the forward fuel cellfor dirt and unwanted material.

3. Apply a light layer of turbine fuel (C-003) on thepacking (21) and install the packing on the pump (8).

CAUTION

WHEN ROUTING THE HOSE ASSEMBLY,MAKE SURE THAT YOU DO NOT KINKTHE HOSE. OTHERWISE, YOU CANCAUSE DAMAGE TO THE HOSE ANDRESTRICT THE TRANSFER OF FUEL TOTHE MAIN FUEL CELL.

4. Install the hose assembly (19) on the tee (20), asshown in Figure 28-5.

CAUTION

DO NOT TORQUE THE TWO BOLTSTHAT ARE INITIALLY INSTALLED TOALIGN PUMP WITH THE FORWARDFUEL CELL.

5. Align the pump (8) with the forward fuel cellattachment plate. Install the pump on the fuel cell withtwo washers (17) and bolts (16).

6. Install the other 10 washers (17) and bolts (16).Torque the 24 bolts (16) .

7. Install 10 washers (23) and bolts (22).

8. Install two washers (25) and bolts (24).

9. Torque the 24 bolts (17, 22, and 24) .

10. Align the two washers (11 and 15) with theretainer (14).

11. Install the retainer (14) on the pump (8) andsecure with the two washers (10 and 13) and twoscrews (9 and 12).

12. Connect the electrical connector 1P13 (3) to theelectrical connector 1J13 (4).


14. Attach the electrical harness clamp (6) to thepump (8) with the screw (5).

15. Connect the helicopter battery (Chapter 96).

16. Fill the fuel system with turbine fuel (C-003)(Chapter 12) and examine for leaks.

17. Align the fuel transfer pump cover with the bottomof the fuselage and secure with 12 washers and 12screws.

28-36. FUEL TRANSFER PUMP CARTRIDGE

For the description of the fuel transfer pump cartridge,refer to paragraph 28-6.

28-37. Fuel Transfer Pump Cartridge — Removal


MATERIALS REQUIRED

NUMBER NOMENCLATURE

C-003 Turbine Fuel


NUMBER NOMENCLATURE

E2-10-1 Slide Hammer

T

T

BHT-407-MM-4


Figure 28-6. Fuel Transfer Pump Cartridge

NO OBJECT BEYOND THIS POINT 407MM_28_0056_c02

ScrewElectrical lead (negative)ScrewElectrical lead (positive)Fuel transfer pump cartridgePlugPackingRetainer ringFuel transfer pump cannisterPacking

1.2.3.4.5.6.7.8.9.

10.

510

24

7

9

8

61

3

SEE DETAIL A

DETAIL A

BHT-407-MM-4


NOTE

The fuel system does not have to bedefueled or drained to remove the fueltransfer pump cartridges.

NOTE

Removal of the left-hand fuel transfer pumpcartridge is described. Removal of theright-hand fuel transfer pump cartridge issimilar.



3. Remove the 12 screws and 12 washers, andremove the fuel transfer pump cover.

4. Remove the screw (1, Figure 28-6) from the fueltransfer pump shutoff lever and remove the negativeelectrical lead (2).

5. Remove the screw (3) from the positive electricallead (4) of the left side fuel transfer pump cartridge (5).

6. Turn the fuel transfer pump shutoff valve leveruntil it is out of the way of the fuel transfer pumpcartridge (5).

7. Remove the lockwire from the left side plug (6).

8. Remove the plug (6) and the packing (7) from thefuel transfer pump cartridge (5). Discard the packingand drain the remaining fuel from the cartridge.

9. Remove the retaining ring (8) from the fueltransfer pump cartridge (5).

10. Install the slide hammer (E2-10-1) in the fueltransfer pump drain boss and remove the left side fuel

transfer pump cartridge (5) from the fuel transfer pumpcannister (9).

11. Install caps and/or plugs (C-428) on the open fueltransfer pump cannister (9).

28-38. Fuel Transfer Pump Cartridge —Inspection

1. Examine the fuel transfer pump cartridge forsigns of pitting and corrosion.

2. Examine the fuel transfer pump cartridge forsigns of external damage.

3. Examine the fuel transfer pump cartridge forsigns of damage or cracks to the electrical leads.

28-39. Fuel Transfer Pump Cartridge —Installation

NOTE

Installation of the left side fuel transferpump cartridge is described. Installation ofthe right side fuel transfer pump cartridge issimilar.

1. Remove the caps and/or plugs from the fueltransfer pump cannister (9, Figure 28-6).

2. Examine the fuel transfer pump left-handcartridge (5) port for unwanted material.

3. Apply a light layer of turbine engine lubricating oil(C-010) on the three packings (10) and to the walls ofthe fuel transfer pump cannister (9).

4. Install the three packings (10) on the fuel transferpump cartridge (5).


MATERIALS REQUIRED

NUMBER NOMENCLATURE



MATERIALS REQUIRED

NUMBER NOMENCLATURE

C-010 Turbine Engine Lubricating Oil

C-405 Lockwire

BHT-407-MM-4

28-00-0023 DEC 2009 Rev. 26 Page 29ECCN EAR99

CAUTION

DO NOT USE FORCE TO PUSH THEFUEL TRANSFER PUMP CARTRIDGEINTO THE FUEL TRANSFER PUMPCANNISTER, OR YOU CAN CAUSEDAMAGE TO THE CARTRIDGE.

NOTE

Make sure that you align the arrows of thefuel transfer pump cartridge (5) and the fueltransfer pump assembly within ±3° of eachother.

5. Install the fuel transfer pump cartridge (5) in thefuel transfer pump cannister (9).

6. Secure the fuel transfer pump cartridge (5) in thefuel transfer pump cannister (9) with the retainingring (8).

7. Apply a light layer of turbine engine lubricating oil(C-010) on the packing (7) and install the packing onthe plug (6).

8. Install the plug (6) in the boss of the fuel transferpump cartridge (5).

9. Safety the plug (6) to the plug on the right-handfuel transfer pump cartridge (5) with lockwire (C-405).

10. Connect the positive electrical lead (4) to the fueltransfer pump cartridge (5) with the screw (3).

CAUTION

MAKE SURE THAT YOU INSTALL THENEGATIVE ELECTRICAL LEAD (2)BETWEEN THE SHUTOFF LEVER ANDTHE FUEL BOOST PUMPCARTRIDGE (5).

11. Turn the fuel transfer pump shutoff lever to theopen position, push, and safety the lever and thenegative electrical lead (2) with the screw (1).


13. Set the LEFT BOOST/XFER switch to the LEFTposition and examine the fuel transfer pump cartridge(5) for signs of leaks.

14. Set the LEFT BOOST/XFER switch to the OFFposition.

15. Install the fuel transfer pump cover and safetywith the 12 washers and 12 screws.

28-40. FUEL TRANSFER PUMP CHECK VALVE

For the description of the fuel transfer pump checkvalve, refer to paragraph 28-6.

28-41. Fuel Transfer Pump Check Valve —Removal


2. Remove the tube assembly (3, Figure 28-7) fromthe left-hand fuel transfer pump check valve (1) andthe tee (4).

3. Remove the tee (4) from the right-hand fueltransfer pump check valve (2).

4. Remove the left-hand fuel transfer pump checkvalve (1) and the packing (6) from the left-hand port inthe fuel transfer pump assembly (5).

5. Remove the right-hand fuel transfer pump checkvalve (2) and the packing (7) from the port in the fueltransfer pump assembly (5).

28-42. Fuel Transfer Pump Check Valve —Inspection

1. Examine the left-hand and the right-hand fueltransfer pump check valves for signs of externaldamage, pitting, and corrosion.

2. Examine the internal mechanism of the fueltransfer pump check valve for signs of damage, pitting,corrosion, and for smooth operation of the valve.Discard the packings.

BHT-407-MM-4


Figure 28-7. Fuel Transfer Pump Check Valve


Check valve

Check valve

Tube assembly

Tee

Fuel transfer pump assembly

Packing

Packing

1.

2.

3.

4.

5.

6.

7.

7

2

4

6

1

3

5

BHT-407-MM-4


3. Examine the threads of the left-hand andright-hand fuel transfer pump check valve for signs ofdamage.

28-43. Fuel Transfer Pump Check Valve —Installation

1. Apply a light layer of turbine fuel (C-003) on thepacking (6, Figure 28-7).

2. Install the packing (6) on the left-hand fueltransfer pump check valve (1) and install the checkvalve in the left-hand port of the fuel transfer pumpassembly (5).

3. Apply a light layer of turbine fuel (C-003) on thepacking (7).

4. Install the packing (7) on the right-hand fueltransfer pump check valve (2) and install the checkvalve in the right-hand port of the fuel transfer pumpassembly (5).

5. Install the tee (4) on the right-hand fuel transferpump check valve (2).

6. Install the tube assembly (3) on the tee (4) andthe left-hand fuel transfer pump check valve (1).

28-44. FUEL TRANSFER PUMP PRESSURESWITCH

For the description of the fuel transfer pump pressureswitch, refer to Chapter 96.

28-45. Fuel Transfer Pump Pressure Switch —Removal/installation

For the removal and installation of the fuel transferpump pressure switch, refer to Chapter 96.

28-46. FUEL TRANSFER PUMP SUMP DRAIN/DEFUEL VALVE

For the description of the fuel transfer pump sumpdrain/defuel valve, refer to Chapter 96.

28-47. Fuel Transfer Pump Sump Drain/DefuelValve — Removal


2. Remove the 12 screws and 12 washers from thefuel transfer pump cover and remove the cover fromthe bottom of the fuselage.




6. Disconnect the two electrical terminals (6, Figure28-8) from the connector.

7. Remove the two bolts (5) and the two washers (4)from the drain valve (3).

8. Remove the drain valve (3) and the packing (2)from the fuel transfer pump assembly (1). Discard thepacking.

9. Install caps and/or plugs (C-428) in the open portof the fuel transfer pump assembly (1).

28-48. Fuel Transfer Pump Sump Drain/DefuelValve — Inspection

1. Examine the fuel transfer pump sump drain/defuel valve for signs of pitting and corrosion.


MATERIALS REQUIRED

NUMBER NOMENCLATURE

C-003 Turbine Fuel


MATERIALS REQUIRED

NUMBER NOMENCLATURE


BHT-407-MM-4

28-00-00Page 32 Rev. 4

Figure ChaptNumber-8.

Figure 28-8. Fuel transfer pump sump drain/defuel valve

BHT-407-MM-4


2. Examine the fuel transfer pump sump drain/defuel valve electrical leads for signs of chafing anddamage to the wire insulation.

3. Examine the fuel transfer pump sump drain/defuel valve for signs of eccentric bolt holes.

28-49. Fuel Transfer Pump Sump Drain/DefuelValve — Installation

1. Apply a light layer of turbine fuel (C-003) on thepacking (2, Figure 28-8).

2. Install the packing (2) on the drain valve (3).

3. Remove the caps and/or plugs from the fueltransfer pump assembly drain valve port.

4. Install the drain valve (3) in the port of the fueltransfer pump assembly (1).

5. Safety the drain valve (3) to the fuel transferpump assembly (1) with the two washers (4) and thetwo bolts (5). Torque the bolts .

6. Connect the two electrical terminals (6) to theconnector.


8. Fill the fuel system of the helicopter with turbinefuel (C-003) (Chapter 12).

9. Examine the drain valve (3) for signs of leaks.

10. Align the fuel transfer pump cover with the bottomof the fuselage and safety the cover with the 12washers and 12 screws.

28-50. FUEL BOOST PUMP ASSEMBLY

For the description of the fuel boost pump assembly,refer to paragraph 28-7.

28-51. Fuel Boost Pump Assembly — Removal


2. Defuel the forward fuel and the main fuel cell(Chapter 12).



5. Remove the 12 screws and 12 washers, andremove the fuel boost pump assembly cover from thebottom of the fuselage.

6. Using extraction tool M81714/69-01, disconnectthe electrical connector 1P11 (1, Figure 28-9) from theconnector 1J11 (2).

7. Using extraction tool M81714/69-01, disconnectthe electrical connector 1P10 (3) from the electricalconnector 1J10 (4).

8. Remove the screw (5) from the clamp (6) andremove the electrical harness (7) from the pump (8).



MATERIALS REQUIRED

NUMBER NOMENCLATURE

C-003 Turbine Fuel

T


NUMBER NOMENCLATURE

M81714/69-01 Extraction Tool


MATERIALS REQUIRED

NUMBER NOMENCLATURE


BHT-407-MM-4


Figure 28-9. Fuel Boost Pump AssemblyNO OBJECT BEYOND THIS POINT 407MM_28_0055_c01

6. Clamp5. Screw

7. Harness

9. Screw

11. Washer

8. Pump

10. Washer

16. Bolt17. Washer

15. Washer14. Retainer13. Washer

20. Tee21. Packing

12. Screw

19. Hose assembly18. Forward fuel cell assembly10

11

4

3

12

13

56

15

7

3.

14

4.

16

2

11.2.

22

20

19

21

8

ConnectorConnector

ConnectorConnector

18

9

24. Bolt25. Washer

23. Washer22. Bolt

B

VIEW B17

2324 25

50 TO 70 IN-LBS MAX(5.65 TO 7.91 Nm MAX)

DETAIL A

SEE DETAIL A

BHT-407-MM-4



11. Remove the retainer (14) and two washers (11and 15) from the pump (8).

12. Remove the 24 bolts (16, 22, and 24) andwashers (17, 23, and 25) from the pump (8).

13. Remove the pump (8) from the main fuel cellassembly (18) and disconnect the hose assembly (19)from the tee (20).

CAUTION

MAKE SURE THAT YOU INSTALL THECAPS AND/OR PLUGS (C-428) ON ALLTHE OPEN LINES AND PORTS OF THEFUEL SYSTEM. THIS PREVENTSCONTAMINATION OF THE SYSTEM.

14. Install caps and/or plugs (C-428) on all open linesand the open port of the main fuel cell.

15. Remove the packing (21) from the pump (8).Discard the packing.

28-52. Fuel Boost Pump Assembly — Inspection

1. Examine the fuel boost pump assembly forcorrosion.

2. Examine the fuel boost pump electrical harnessfor signs of rubbing, wear, cracked wires, and damageto the electrical connectors.

3. Examine the mating surface of the main fuel celland the fuel boost pump assembly for signs of leaks.

4. Examine the fuel boost pump assembly foreccentric bolt holes.

5. Examine the bolt hole threads of the main fuelcell for signs of damage.

28-53. Fuel Boost Pump Assembly — Installation

1. Remove the caps and/or plugs from the main fuelcell open port and from the hose assembly (19,Figure 28-9).

2. Examine the internal part of the main fuel cell fordirt and unwanted material.

3. Apply a light layer of turbine fuel (C-003) on thepacking (21) and install the packing on the pump (8).

4. Install the hose assembly (19) on the tee (20).

CAUTION

DO NOT TORQUE THE TWO BOLTSTHAT ARE INITIALLY INSTALLED TOALIGN THE PUMP WITH THE MAIN FUELCELL.

5. Align the pump (8) with the main fuel cellattachment plate. Install the pump on the fuel cell withtwo washers (17) and bolts (16).

6. Install the other 10 washers (17) and bolts (16).Torque the bolts .

7. Install 10 washers (23) and bolts (22).

8. Install two washers (25) and bolts (24).

9. Torque the bolts (17, 22, and 24) .

10. Align the two washers (11 and 15) on theretainer (14).

11. Install the retainer (14) on the pump (8) andsecure with the two washers (10 and 13) and twoscrews (9 and 12).


MATERIALS REQUIRED

NUMBER NOMENCLATURE

C-003 Turbine Fuel

T

T

BHT-407-MM-4




14. Attach the electrical harness clamp (6) to thepump (8) with the screw (5).


16. Fill the helicopter fuel system with turbine fuel(C-003) (Chapter 12) and examine for leaks.

17. Align the fuel boost pump cover with the bottomof the fuselage and secure with 12 washers and 12screws.

28-54. FUEL BOOST PUMP CARTRIDGE

For the description of the fuel boost pump cartridge,refer to paragraph 28-7.

28-55. Fuel Boost Pump Cartridge — Removal

NOTE

It is not necessary to defuel the main fuelcell to remove the fuel boost pumpcartridge.

NOTE

Removal of the left-hand fuel boost pumpcartridge is described. Removal of theright-hand fuel boost pump cartridge issimilar.



3. Remove the 12 screws and 12 washers, andremove the fuel boost pump cover.

4. Remove the screw (1, Figure 28-10) from fuelboost pump shutoff lever and remove the negativeelectrical lead (2).

5. Remove the screw (3) from the positive electricallead (4) of the left-hand fuel boost pump cartridge (5).

6. Turn the fuel boost pump shutoff valve lever untilit is out of the way of the fuel boost pump cartridge (5).

7. Remove the lockwire from the left-hand plug (6).

8. Remove the plug (6) and the packing (7) from thefuel boost pump cartridge (5). Discard the packing anddrain the remaining fuel from the cartridge.

9. Remove the retainer ring (8) from the fuel boostpump cartridge (5).

10. Install the slide hammer (E2-10-1) in the fuelboost pump drain boss and remove the left-hand fuelboost pump cartridge (5) from the fuel boost pumpcannister (9).

11. Install caps and/or plugs (C-428) on the open fuelboost pump cannister (9).

28-56. Fuel Boost Pump Cartridge — Inspection

1. Examine the fuel boost pump cartridge for signsof pitting and corrosion.

2. Examine the fuel boost pump cartridge for signsof external damage.

3. Examine the fuel boost pump cartridge for signsof damage or cracks to the electrical leads.


NUMBER NOMENCLATURE

E2-10-1 Slide Hammer


MATERIALS REQUIRED

NUMBER NOMENCLATURE


BHT-407-MM-4


Figure 28-10. Fuel Boost Pump Cartridge

NO OBJECT BEYOND THIS POINT 407MM_28_0057_c02

ScrewElectrical lead (negative)ScrewElectrical lead (positive)Fuel boost pump cartridgePlugPackingRetainer ringFuel boost pump cannisterPacking

1.2.3.4.5.6.7.8.9.

10.

510

24

7

9

8

61

3

SEE DETAIL A

DETAIL A

BHT-407-MM-4


28-57. Fuel Boost Pump Cartridge — Installation

NOTE

Installation of the left-hand fuel boost pumpcartridge is described. Installation of theright-hand fuel boost pump cartridge issimilar.

1. Remove the caps and/or plugs from the fuelboost pump cannister (9, Figure 28-10).

2. Examine the left-hand fuel boost pump cartridge(5) port for unwanted objects.

3. Apply a light layer of turbine engine lubricating oil(C-010) on the three packings (10) and to the walls ofthe fuel boost pump cannister (9).

4. Install the three packings (10) on the fuel boostpump cartridge (5).

CAUTION

DO NOT USE FORCE TO PUSH THEFUEL BOOST PUMP CARTRIDGE INTOTHE FUEL BOOST PUMP CANNISTER,OR YOU CAN CAUSE DAMAGE TO THECARTRIDGE.

NOTE

Make sure that you align the arrows of thefuel boost pump cartridge (5) and the fuelboost pump assembly within ±3° of eachother.

5. Install the fuel boost pump cartridge (5) in the fuelboost pump cannister (9).

6. Safety the fuel boost pump cartridge (5) in thefuel boost pump cannister (9) with the retainer ring (8).

7. Apply a light layer of turbine engine lubricating oil(C-010) on the packing (7) and install the packing onthe plug (6).

8. Install the plug (6) in the boss of the fuel boostpump cartridge (5).

9. Safety the plug (6) to the plug on the right-handfuel boost pump cartridge (5) with lockwire (C-405).

10. Connect the positive electrical lead (4) to the fuelboost pump cartridge (5) with the screw (3).

CAUTION

MAKE SURE THAT YOU INSTALL THENEGATIVE ELECTRICAL LEAD (2)BETWEEN THE SHUTOFF LEVER ANDTHE FUEL BOOST PUMPCARTRIDGE (5).

11. Turn the fuel boost pump shutoff lever to the openposition, push, and safety the lever and the negativeelectrical lead (2) with the screw (1).


13. Examine the fuel boost pump cartridge (5) forsigns of leaks.

14. Install the fuel boost pump cover and safety withthe 12 washers and 12 screws.

28-58. FUEL BOOST PUMP CHECK VALVE

For the description of the fuel boost pump check valve,refer to paragraph 28-7.

28-59. Fuel Boost Pump Check Valve — Removal


2. Remove the tube assembly (3, Figure 28-11)from the left-hand fuel boost pump check valve (1) andthe tee (4).


MATERIALS REQUIRED

NUMBER NOMENCLATURE

C-010 Turbine Engine Lubricating Oil

C-405 Lockwire

BHT-407-MM-4

28-00-00

ECCN EAR99

Figure 28-11. Fuel Boost Pump Check Valve


Check valve

Check valve

Tube assembly

Tee

Fuel boost pump assembly

Packing

Packing

1.

2.

3.

4.

5.

6.

7.

7

2

4

6

1

3

5

23 DEC 2009 Rev. 26 Page 38A

BHT-407-MM-4

28-00-00ECCN EAR99

3. Remove the tee (4) from the right-hand fuel boostpump check valve (2).

4. Remove the left-hand fuel boost pump checkvalve (1) and the packing (6) from the left-hand port inthe fuel boost pump assembly (5).

5. Remove the right-hand fuel boost pump checkvalve (2) and the packing (7) from the port in the fuelboost pump assembly (5).

28-60. Fuel Boost Pump Check Valve —Inspection

1. Examine the left-hand and right-hand fuel boostpump check valve for signs of external damage,pitting, and corrosion.

2. Examine the internal mechanism of the fuel boostpump check valve for signs of damage, pitting,corrosion, and for smooth operation.

3. Examine the threads of the left-hand and theright-hand fuel boost pump check valve for signs ofdamage.

Page 38B Rev. 26 23 DEC 2009

BHT-407-MM-4


28-61. Fuel Boost Pump Check Valve —Installation

1. Apply a light layer of turbine fuel (C-003) on thepacking (6, Figure 28-11) and install packing on theleft-hand side fuel boost pump check valve (1).

2. Install left-hand side fuel boost pump check valve(1) in the left-hand side port of the fuel boost pumpassembly (5).

3. Apply a light layer of turbine fuel (C-003) on thepacking (7) and install packing on the right-hand sidefuel boost pump check valve (2).

4. Install right-hand side fuel boost pump checkvalve (2) in the right-hand side port of the fuel boostpump assembly (5).

5. Install tee (4) on the right-hand side fuel boostpump check valve (2).

6. Install tube assembly (3) on tee (4) and theleft-hand side fuel boost pump check valve (1).

28-62. FUEL BOOST PUMP PRESSURE SWITCH

For the description of the fuel boost pump pressureswitch, refer to Chapter 96.

28-63. Fuel Boost Pump Pressure Switch —Removal and Installation

For the removal and installation of the fuel boost pumppressure switch, refer to Chapter 96.

28-64. FUEL BOOST PUMP SUMP DRAIN/DEFUEL VALVE

For the electrical description of the fuel boost pumpsump drain/defuel valve, refer to Chapter 96. For the

description of the fuel boost pump sump/defuel valve,refer to paragraph 28-7.

28-65. Fuel Boost Pump Sump Drain/DefuelValve — Removal


2. Remove the 12 screws and washers from the fuelboost pump cover and remove the cover from thebottom of the fuselage.




6. Disconnect the two electrical terminals (6,Figure 28-12) from the connector.

7. Remove bolts (5) and washers (4) from the drainvalve (3).

8. Remove the drain valve (3) and packing (2) fromthe fuel boost pump assembly (1). Discard thepacking.

9. Install caps and/or plugs (C-428) in the open portof the fuel boost pump assembly (1).

28-66. Fuel Boost Pump Sump Drain/DefuelValve — Inspection

1. Examine the fuel boost pump sump drain/defuelvalve for signs of pitting and corrosion.

2. Examine the valve electrical leads for signs ofrubbing, wear, and damage to the wire insulation.


MATERIALS REQUIRED

NUMBER NOMENCLATURE

C-003 Turbine FuelRefer to BHT-ALL-SPM for specifications.

MATERIALS REQUIRED

NUMBER NOMENCLATURE


BHT-407-MM-4


Figure 28-12. Fuel Boost Pump Sump Drain/Defuel Valve407MM_28_0024

Fuel transfer pump assemblyPackingDrain valveWasherBoltElectrical terminals

1.2.3.4.5.6.

12

3

4

5

6

50 TO 75 IN-LBS(5.65 TO 8.47 Nm)

BHT-407-MM-4


3. Examine the valve for signs of eccentric boltholes.

28-67. Fuel Boost Pump Sump Drain/DefuelValve — Installation

1. Apply a light layer of turbine fuel (C-003) onpacking (2, Figure 28-12).

2. Install packing (2) on drain valve (3).

3. Remove the caps and/or plugs from the fuelboost pump assembly drain valve port.

4. Install the drain valve (3) in the port of the fuelboost pump assembly (1).

5. Secure the drain valve (3) to the fuel boost pumpassembly (1) with two washers (4) and bolts (5).Torque the bolts .

6. Connect the two electrical terminals (6) to theconnector.


8. Fill the fuel system with turbine fuel (C-003)(Chapter 12).

9. Examine the drain valve (3) for signs of leaks.

10. Align the fuel boost pump cover with the bottomof the fuselage and secure with 12 washers and 12screws.

28-68. FUEL CELL INTERCONNECT SYSTEM

The fuel cell interconnect system is installed betweenthe forward fuel cell and the main fuel cell. The systemis made up of a pressure feed interconnect hose, agravity feed interconnect hose, and a standpipeinstalled in the main fuel cell.

The pressure feed hose is connected to the fueltransfer pump assembly through a flexible hose. Thepressure feed hose is smaller in diameter than thegravity feed line and is used to transfer fuel throughthe fuel transfer pump assembly from the forward fuelcell to the main fuel cell.

The gravity feed hose is larger in diameter than thepressure feed hose and is connected to the standpipelocated in the main fuel cell. The gravity feed hosegets fuel through the standpipe located in the main fuelcell and transfers the fuel to the forward fuel cell.

28-69. Fuel Cell Interconnect — Removal


2. Defuel the helicopter (Chapter 12).

3. Drain the helicopter sumps (Chapter 12).




7. Purge the forward fuel cell and the main fuel cell(Chapter 12).

8. Remove the screws and washers from the fuelcell interconnect cover.

9. In the main fuel cell (7, Figure 28-21), remove thenut (26), washers (27 and 28), and screw (23) from theclamp (24) and bracket (25).

10. Remove the fuel quantity harness (4) from theclamp (24).

11. Remove the fuel quantity harness from theforward fuel cell (paragraph 28-103, step 10 throughstep 15).

NOTE

To allow reinstallation of the fuel quantityharness into the forward fuel cell, leave thecord in position between the forward and aftfuel cells.


MATERIALS REQUIRED

NUMBER NOMENCLATURE

C-003 Turbine Fuel

T

BHT-407-MM-4


12. Untie the cord from the forward fuel quantityprobe connector.

13. Remove the nut (1, Figure 28-13) and washer (2)from the hose assembly (3) in the forward fuel cell.

14. Remove bolts (4) and washers (5) from theretainer (6).

15. Remove the retainer (6) and packing (7) from theforward fuel cell mount plate (8). Discard the packing.

16. Remove bolts (9), washers (10), andpackings (11) from the retainer (12).

17. Remove the retainer (12) from the forward fuelcell mount plate (8).

18. Remove the screw (54), washer (33), andnut (34) from the bracket (56).

19. Remove the tube assembly (38) from the hoseassembly (3).

20. Remove screw (32), washers (33), and nut (34)from brackets (56 and 58).

21. Remove bolts (25), washers (26), andpackings (27) from the retainer (28).

22. Remove the standpipe (17), the retainer (28), andthe packing (29) from the main fuel cell mountplate (24). Discard the packing.

23. Remove the nut (19) and the washer (20) fromthe hose assembly (3) in the main fuel cell (40).

24. Remove the two bolts (21) and the twowashers (22) from the retainer (18).

25. Remove the retainer (18) and the packing (23)from the main fuel cell mount plate (24). Discard thepacking.

26. Remove the two screws (35), and the twowashers (36) from the two clamps (37).

27. Remove the two clamps (37) from the hoseassembly (3).

28. Remove the hose assembly (3) from the forwardfuel cell (39) and the main fuel cell (40).

29. Remove the three bolts (41) from the fittingassembly (42).

30. Remove the hose assembly (43) and thepacking (44) from the fitting assembly (42). Discardthe packing.

31. Remove the two nuts (45), the two washers (46),and the two bolts (47) from the clamp assembly (48).

32. Remove the top and bottom sections of the clampassembly (48) from the hose assembly (43).

33. Remove the hose assembly (43) and thepacking (49) from the fitting on the main fuel cell (40).Discard the packing.

34. Remove the two bolts (50) and the twowashers (51) from the fitting assembly (42).

35. Remove the fitting assembly (42) and thepacking (52) from the forward fuel cell mount plate (8).Discard the packing.

36. Install caps and/or plugs (C-428) on the openports of the forward fuel cell (39) and the main fuelcell (40).

28-70. Fuel Cell Interconnect — Inspection

1. Examine the forward fuel cell mount plates (8,Figure 28-13) for signs of pitting, corrosion, and leaks.

2. Examine the main fuel cell mount plates (24) forsigns of pitting, corrosion, and leaks.

3. Examine the fitting assembly (42) for signs ofpitting, corrosion, damage to the flanges, andeccentric bolt holes.

4. Examine the hose assembly (43) for signs ofdamage and corrosion to the stainless steel braid,forward fitting, and aft fitting flange, and for eccentricbolt holes.

5. Examine the hose assembly (3) for signs ofdamage and corrosion to the stainless steel braid, andto the forward and the aft fittings.

BHT-407-MM-4


Figure 28-13. Fuel Cell Interconnect Tube Assembly (Sheet 1 of 2)NO OBJECT BEYOND THIS POINT 407MM_28_0053a_c01

21

22

18

19

20

23

25

26

27

29

244024

49

47

46

48

48

45

35

43

41

3637

3

444252

5150

8

398

11

109

12

7

4

5

61

2

28

1 6

7

5

4

38

2

54

C

C

11

27

12

28

17

38

36

37

35

SEE DETAIL ASEE DETAIL D

SEE DETAIL B

DETAIL B

VIEW C-C

SEE DETAIL B

DETAIL A

BHT-407-MM-4


Figure 28-13. Fuel Cell Interconnect Tube Assembly (Sheet 2 of 2)

NO OBJECT BEYOND THIS POINT 407MM_28_0053b_c01

57

34

33

NutWasherHose assemblyBoltWasherRetainerPackingForward fuel cell mount plateBoltWasherPackingRetainerScrewWasherSpacerClipStandpipeRetainerNutWasher

1.2.3.4.5.6.7.8.9.

10.11.12.13.14.15.16.17.18.19.20.

BoltWasherPackingMain fuel cell mount plateBoltWasherPackingRetainerPackingNutClampScrewWasherNutScrewWasherClampTube assemblyForward fuel cellMain fuel cell

21.22.23.24.25.26.27.28.29.30.31.32.33.34.35.36.37.38.39.40.

BoltFitting assemblyHose assemblyPackingNutWasherBoltClamp assemblyPackingBoltWasherPackingClampScrewClampBracketBoltBracketSpacer

41.42.43.44.45.46.47.48.49.50.51.52.53.54.55.56.57.58.59.

56

5832

1430

3014

31 1413

16

1413

59

54

55

3334

53

38

17

15

120 TO 150 IN-LBS(13.60 TO 16.90 Nm)

DETAIL D

BHT-407-MM-4


28-71. Fuel Cell Interconnect — Installation

1. Remove the caps and/or plugs from the ports ofthe forward fuel cell (39, Figure 28-13) and the mainfuel cell (40).

2. Examine the forward fuel cell (39) and the mainfuel cell (40) for signs of dirt and unwanted objects.Make sure the fuel cells are clean.

3. Apply a light layer of turbine fuel (C-003) on thepacking (52) and install the packing in the groove onthe fitting assembly (42).

4. Align the fitting assembly (42) on the forward fuelcell mount plate (8).

NOTE

To allow reinstallation of the fuel quantityharness from the main to forward fuel cell,feed a sufficient length of cord (C-480)through the hose assembly (43) andstandpipe (17) during installation. The cordwill be used to pull the fuel quantity harnessfrom the main fuel cell through thecomponents and into the forward fuel cell.

5. Apply a light layer of turbine fuel (C-003) on thefour packings (11) and install the packings in therecesses of the retainer (12).

6. Align the retainer (12) on the forward fuel cellmount plate (8).

7. Secure the retainer (12) and the fittingassembly (42) to the forward fuel cell mount plate (8)with the four washers (10) and bolts (9).

8. Install the fuel quantity harness (paragraph28-105, step 5 through step 13). Remove the cordfrom the forward fuel cell.

9. Apply a light layer of turbine fuel (C-003) on thepacking (49) and install packing on the aft fitting of thehose assembly (43).

10. Align the aft fitting of the hose assembly (43) onthe main fuel cell mount plate (24).

11. Apply a light layer of turbine fuel (C-003) onpackings (27 and 29) and install packings in thebottom side recesses of the retainer (28).

12. Align the retainer (28) on the main fuel cell mountplate (24).

13. Secure the retainer (28) and the standpipe (17) tothe main fuel cell mount plate (24) and aft fitting of thehose assembly (43) with four washers (26) andbolts (25).

14. Apply a light layer of turbine fuel (C-003) onpacking (44) and install packing on the forward fittingof hose assembly (43).

15. Install the hose assembly (43) in the fittingassembly (42) and secure with three bolts (41).

16. Secure the fitting assembly (42) to the structurewith two washers (51) and bolts (50).

17. Align the top and bottom section of the clampassembly (48) on the hose assembly (43) and securethe clamp assembly to the structure with bolts (47),washers (46), and nuts (45).

18. Install the hose assembly (3) through the openports of the forward fuel cell mount plate (8) and mainfuel cell mount plate (24).

19. Apply a light layer of turbine fuel (C-003) onpacking (23) and install packing in the recess of theretainer (18).

20. Install the retainer (18) on the main fuel cellmount plate (24) and secure with washers (22) andbolts (21).


MATERIALS REQUIRED

NUMBER NOMENCLATURE

C-003 Turbine Fuel

C-480 Cord

BHT-407-MM-4


21. Secure the hose assembly (3) to the main fuelcell mount plate (24) with washer (20) and nut (19).Torque the nut .

22. Install the tube assembly (38) on the fitting of thehose assembly (3).

23. Apply a light layer of turbine fuel (C-003) onpacking (7) and install packing in the recess of theretainer (6).

24. Install the retainer (6) on the forward fuel cellmount plate (8) and secure with washers (5) andbolts (4).

25. Secure the hose assembly (3) to the forward fuelcell mount plate (8) with washer (2) and nut (1). Torquethe nut .

26. Install the two clamps (37) on the hoseassembly (3) and secure with washers (36) andscrews (35).

27. Secure the standpipe (17) to the bracket (58) ofthe main fuel cell (40) with the screw (32), bracket(56), clamp (53), washer (33), and nut (34).

28. Secure the standpipe (17) to the tube assembly(38) with the screw (54), clamp (55), washer (33), andthe nut (34).

29. Install the clamp (31) on the fuel quantity harnessat the top of the standpipe (17).

30. Install the clamp (31) on the bracket (16) with thescrew (13), washers (14), and nut (30).

31. Make sure the fuel quantity harness is positionedso that chafing will not occur.

CAUTION

DO NOT CONNECT THE HELICOPTERELECTRICAL POWER OR FILL THEFUEL SYSTEM UNTIL THE FUELTRANSFER PUMP ASSEMBLY AND THEFUEL BOOST PUMP ASSEMBLY AREINSTALLED.

NOTE

Do not install the fuel transfer pump coverand the fuel boost pump cover until a leakcheck has been done.


33. Install the fuel boost pump assembly (paragraph28-53).


35. Fill the helicopter fuel system with turbine fuel(C-003) and examine the fuel cell interconnect, thefuel transfer pump assembly, and the fuel boost pumpassembly for leaks.

36. Align the fuel transfer pump cover with the bottomof the fuselage and safety the cover with the washersand screws.

37. Align the fuel boost pump cover with the bottomof the fuselage and safety the cover with the washersand screws.

38. Install the fuel cell interconnect cover and safetythe cover with the washers and screws.

28-72. FUEL PRESSURE TRANSDUCER

For the description of the fuel pressure transducer,refer to Chapter 95.

28-73. Fuel Pressure Transducer — Removal andInstallation

For the removal and installation procedure of the fuelpressure transducer, refer to Chapter 95.

28-74. Fuel Pressure Transducer — Inspection

1. Examine the fuel pressure transducer for signs ofexternal damage.

2. Examine the fuel pressure transducer for signs ofpitting and corrosion.

3. Examine the inlet port of the fuel pressuretransducer for signs of damage and blockage.

T

T

BHT-407-MM-4

28-00-00

ECCN EAR99

4. Examine the fuel pressure transducer electricalconnector for signs of corrosion and damage to theelectrical pins.

28-75. FUEL SHUTOFF VALVE

For the description of the fuel shutoff valve, refer toparagraph 28-7.

28-76. Fuel Shutoff Valve — Removal



3. Remove the hat bin panel assembly (Chapter 25).

4. Remove the 17 screws and washers from the fuelshutoff valve access panel.

5. Disconnect the electrical connector (1,Figure 28-14) from the fuel shutoff valve (2).

6. Remove the fuel inlet line (3) from the inlet port ofthe fuel shutoff valve (2).

7. Remove the fuel outlet line (4) from the outlet portof the fuel shutoff valve (2).

8. Install caps and/or plugs (C-428) on all open linesand ports.

9. Remove four nuts (5), washers (6), and bolts (7)from the fuel shutoff valve (2), and remove the valvefrom the left and right bracket (8).


MATERIALS REQUIRED

NUMBER NOMENCLATURE


26 FEB 2010 Rev. 27 Page 46A/46B

BHT-407-MM-4

28-00-00Rev. 4 Page 47


Figure 28-14. Fuel shutoff valve

BHT-407-MM-4

28-00-00Page 48 Rev. 36 18 JUN 2013 Export Classification C, ECCN EAR99

28-77. Fuel Shutoff Valve — Inspection

1. Examine the fuel shutoff valve for pitting andcorrosion.

2. Examine the fuel shutoff valve for signs ofoverheating.

3. Examine the fuel shutoff valve for damage orblockage to the inlet and outlet ports.

4. Examine the fuel shutoff valve electricalconnector for signs of damage and corrosion to theelectrical pins.

28-78. Fuel Shutoff Valve — Installation

1. Align the fuel shutoff valve (2, Figure 28-14) withthe left and right bracket (8) and safety the valve withthe four bolts (7), washers (6), and nuts (5).

2. Remove all the caps and/or plugs from the linesand ports.

3. Install the fuel outlet line (4) on the outlet port ofthe fuel shutoff valve (2).

4. Install the fuel inlet line (3) on the inlet port of thefuel shutoff valve (2).

5. Connect the electrical connector (1) to thereceptacle on the fuel shutoff valve (2).

6. Install the fuel shutoff valve access panel on thestructure and safety the panel with the 17 washers andscrews.

7. Install the hat bin panel assembly (Chapter 25).

8. Connect the helicopter electrical power(Chapter 96).

28-79. FUEL FILTER ASSEMBLY

For the description of the fuel filter assembly, refer toparagraph 28-7.

28-80. Fuel Filter Assembly — Removal


2. Remove the helicopter electrical power(Chapter 96).

3. Open the right lower engine cowl (Chapter 53).

4. Disconnect the electrical connector (5,Figure 28-15) from the receptacle on the fuel filter (6).

5. Turn the handle on the drain valve (13) anddrain the fuel filter (6).

NOTE

Install caps and/or plugs (C-428) on theopen line and ports.

6. Remove the drain hose (12) from the manualdrain valve (13).

7. Loosen the nut (11), and remove the manualdrain valve (13) and the packing (10) from the fuel filter(6). Discard the packing.

CAUTION

DO NOT KINK, BEND, OR TWIST THEFUEL HOSE BEYOND ALLOWABLELIMITS (INFORMATION LETTER (IL)407-98-19). IF A FUEL HOSE HAS BEENKINKED, BENT, OR TWISTED BEYONDLIMITS, OR IS SUSPECTED OF THISOCCURRENCE, IT SHALL BEREPLACED WITH A SERVICEABLE FUELHOSE PRIOR TO RETURNING THEHELICOPTER TO SERVICE.

8. Remove the fuel inlet hose (9) from the inletfitting (8).


MATERIALS REQUIRED

NUMBER NOMENCLATURE


BHT-407-MM-4

28-00-00Rev. 4 Page 49


Figure 28-15. Fuel filter assembly

BHT-407-MM-4

28-00-00Page 50 Rev. 36 18 JUN 2013 Export Classification C, ECCN EAR99

9. Remove the inlet fitting (8) and the packing (7)from the inlet port of the fuel filter (6). Discard thepacking.

CAUTION


10. Remove the fuel outlet hose (2) from the outletfitting (3).

11. Remove the outlet fitting (3) and the packing (4)from the outlet port of the fuel filter (6).

12. Remove the lockwire from the three bolts (17).

13. Remove the three bolts (17) and the washers (16)from the fuel filter (6).

14. Remove the fuel filter assembly (6) and the threewashers (15) from the mount bracket (14).

15. Remove the three washers (15) from the fuelfilter (6).

28-81. Fuel Filter Assembly — Inspection

1. Examine the fuel filter assembly for signs ofleaks.

2. Examine the fuel filter assembly for signs ofpitting and corrosion.

3. Examine the fuel filter impending bypass testswitch for proper operation.

4. Examine the inlet, outlet, and drain ports of thefuel filter assembly for signs of damage and blockage.

28-82. Fuel Filter Assembly — Installation

1. Align the fuel filter (6, Figure 28-15) with themount bracket (14).

2. Install the three washers (15) between the fuelfilter (6) and the mount bracket (14).

3. Safety the fuel filter (6) to the mount bracket (14)with the three washers (16) and the bolts (17).

4. Safety the three bolts (17) with lockwire (C-405).

5. Remove the caps and/or plugs (C-428) from thelines and the ports of the fuel filter (6).

6. Apply a light layer of turbine fuel (C-003) on thepacking (4) and install the packing on the outletfitting (3).

7. Install the outlet fitting (3) in the outlet port of thefuel filter (6).

CAUTION


8. Install the fuel outlet hose (2) on the outletfitting (3).


MATERIALS REQUIRED

NUMBER NOMENCLATURE

C-003 Turbine Fuel

C-405 Lockswire


BHT-407-MM-4

28-00-00Export Classification C, ECCN EAR99

9. Apply a light layer of turbine fuel (C-003) on thepacking (7) and install the packing on the inletfitting (8).

10. Install the inlet fitting (8) in the inlet port of the fuelfilter (6).

CAUTION

DO NOT KINK, BEND, OR TWIST THEFUEL HOSE BEYOND ALLOWABLELIMITS (INFORMATION LETTER (IL)407-98-19). IF A FUEL HOSE HAS BEENKINKED, BENT, OR TWISTED BEYONDLIMITS, OR IS SUSPECTED OF THISOCCURRENCE, IT SHALL BE REPLACEDWITH A SERVICEABLE FUEL HOSEPRIOR TO RETURNING THEHELICOPTER TO SERVICE.

11. Install the fuel inlet hose (9) on the inlet fitting (8).

12. Apply a light layer of turbine fuel (C-003) on thepacking (10) and install the packing on the manualdrain valve (13).

13. Install the manual drain valve (13) in the drainport of the fuel filter (6) and safety with the nut (11).

14. Install the drain hose (12) on the manual drainvalve (13).

15. Connect the electrical connector (5) to thereceptacle on the fuel filter (6).

16. Connect the helicopter electrical power(Chapter 96).

17. On the overhead console, set the LEFT BOOST/XFER pump and the RIGHT BOOST/XFER pumpswitches to ON to pressurize the fuel system.

18. Examine the fuel filter assembly for signs ofleaks.

19. Set the LEFT BOOST/XFER and the RIGHTBOOST/XFER switch to OFF.

20. Close the right lower engine cowl (Chapter 53).

28-83. FUEL FILTER ELEMENT

1. The fuel filter element is installed in the fuel filterbowl and is made up of a filter element, a top, and abottom seal. The filter is a 10-micron nominal element;it is used to filter the fuel and trap ice before it gets tothe engine fuel pump.

28-84. Fuel Filter Element — Replacement


2. Disconnect the helicopter electrical power(Chapter 96).

3. Open the right lower engine cowl (Chapter 53).

4. Turn the handle on the manual drain valve (8,Figure 28-16) and drain the fuel from the fuel filterbowl (4).

18 JUN 2013 Rev. 36 Page 50A/50B

BHT-407-MM-4

28-00-00Rev. 4 Page 51

NOTE

Install caps and/or plugs (C-428, BHT-ALL-SPM) on the open drain line.

5. Remove the drain hose (7) from the manual drain valve (8).

6. Loosen the nut (6) and remove the manual drain valve (8) and the packing (5) from the fuel filter bowl (4). Discard the packing.

7. Remove the lockwire from the filter bowl (4) and the filter head (1).

8. Turn the filter bowl (4) and unscrew the bowl from the filter head (1).

9. Remove and discard the filter element (10), the filter head element seal (3), the filter bowl seal (9) and the packing (2).

10. Apply a light layer of turbine fuel (C-003, BHT-ALL-SPM) on the packing (2) and install the packing on the filter head (1).

11. Install the element seal (3) on the filter head (1) and the element seal (9) on the filter bowl (4).

12. Install the filter element (10) in the filter bowl (4).

13. Align the filter bowl (4) with the filter head (1) and install the bowl on the filter head.

14. Safety the filter bowl (4) to the filter head (1) with lockwire (C-405, BHT-ALL-SPM).

15. Apply a light layer of turbine fuel (C-003, BHT-ALL-SPM) on the packing (5) and install the packing in the drain port of the filter bowl (4).

16. Install the manual drain valve (8) in the drain port of the filter bowl (4) and safety with the nut (6).

17. Install the drain line (7) on the manual drain valve (8).

18. Connect the helicopter electrical power (Chapter 96).

19. On the overhead console, set the LEFT BOOST/XFER and RIGHT BOOST/XFER pump switch to ON to pressurize the fuel system.

20. Examine the fuel filter assembly for signs of leaks.

21. Set the LEFT BOOST/XFER pump and the RIGHT BOOST/XFER pump switch to OFF.

22. Close the right lower engine cowl (Chapter 53).

28-85. FUEL INDICATION

For the electrical description and operation of the fuel quantity indication fuel probes, refer to Chapter 95. For the electrical description and operation of the fuel quantity indication low level switches, refer to Chapter 96. For the description of the fuel indication system, refer to Paragraph 28-9.

28-86. FORWARD FUEL CELL FUEL QUANTITY PROBE.

For the electrical description and operation of the forward fuel cell fuel quantity probe, refer to Chapter 95. For the description of the forward fuel cell fuel quantity probe, refer to Paragraph 28-9.

28-87. Forward fuel cell fuel quantity probe — Removal


2. Defuel the helicopter (Chapter 12).

3. Drain the helicopter (Chapter 12).

4. Remove the fuel transfer pump (Paragraph 28-33).

5. Disconnect the electrical connector (1, Figure 28-17) from the receptacle on the fuel quantity probe (2).

6. Remove the two nuts (3), the washers (4) and the screws (5) from the two clamps (6).

7. Remove the two clamps (6) from the fuel quantity probe (2).

8. Remove the three bolts (7) and washers (8) from the three fuel probe mount inserts.

9. Remove the fuel quantity probe (2) from the forward fuel cell (9).

BHT-407-MM-4

28-00-00Page 52 Rev. 4


Figure 28-16. Fuel filter element

BHT-407-MM-4


Figure 28-17. Forward Fuel Cell Fuel Quantity Probe407MM_28_0041

ConnectorProbe - fuel quantity forward tankNutWasherScrewClampBoltWasherForward fuel cellClamp

1.2.3.4.5.6.7.8.9.

10.

40 IN-LBS MAX (4.52 Nm MAX)

7

8

92

1

10

4

5

6

3

BHT-407-MM-4


28-88. Forward Fuel Cell Fuel Quantity Probe —Inspection

1. Examine the fuel quantity probe for signs ofexternal damage, pitting, and corrosion.

2. Examine the fuel quantity probe electricalreceptacle for signs of damage to the pins.

28-89. Forward Fuel Cell Fuel Quantity Probe —Installation

1. Install the fuel quantity probe (2, Figure 28-17) inthe forward fuel cell (9) and safety the probe to thethree fuel probe mount inserts with the three washers(8) and bolts (7). Torque the three bolts (7) .

NOTE

Refer to Figure 28-21 for dimensional detailof installed clamping positions.

2. Install the two clamps (6, Figure 28-17) on thefuel quantity probe (2).

3. Align the two clamps (6) with the two clamps (10)and secure with the two screws (5), washers (4), andnuts (3).

4. Connect the electrical connector (1) to thereceptacle of the fuel quantity probe (2).


6. Fill the helicopter fuel system with turbine fuel(C-003) (Chapter 12) and examine for signs of leaks.

7. Verify correct operation of the fuel quantitygauging system (Chapter 95).

28-90. FORWARD FUEL CELL LOW LEVELSWITCH

For the electrical description and operation of theforward fuel cell low level switch, refer to Chapter 96.For the description of the forward fuel cell low levelswitch, refer to paragraph 28-9.

28-91. Forward Fuel Cell Low Level Switch —Removal





5. Remove the screw (8, Figure 28-18) and thewasher (7) from the retainer (11).

6. Remove the screw (9) and the washer (10) fromthe retainer (11).

7. Remove the retainer (11) and the two washers (6and 12) from the pump (1).

8. Disconnect the electrical terminals (13) from theconnector on the pump (1).

9. Remove the two bolts (5) and the two washers (4)from the switch (3).

10. Remove the switch (3) and the packing (2) fromthe pump (1). Discard the packing.

28-92. Forward Fuel Cell Low Level Switch —Inspection

1. Examine the switch for signs of external damage,pitting, and corrosion.

2. Examine the switch electrical lead for signs ofchafing and cracks in the insulation.

3. Examine the switch for eccentric bolt holes.


MATERIALS REQUIRED

NUMBER NOMENCLATURE

C-003 Turbine Fuel

T

BHT-407-MM-4

28-00-00Rev. 4 Page 55


Figure 28-18. Forward fuel cell low level switch

BHT-407-MM-4


28-93. Forward Fuel Cell Low Level Switch —Installation

1. Apply a light layer of turbine fuel (C-003) on thepacking (2, Figure 28-18) and install the packing onthe switch (3).

2. Install the switch (3) in the port of the fuel transferpump (1).

3. Secure the switch (3) to the pump (1) with the twowashers (4) and the two bolts (5).

4. Connect the electrical terminals (13) to theconnector on the pump (1).

5. Install the washer (7), the screw (8), thewasher (10), and the screw (9) through theretainer (11).


7. Install the retainer (11) on the pump (1).


9. Fill the helicopter fuel system with turbine fuel(C-003) (Chapter 12) and examine the switch (3) forleaks.

28-94. AFT FUEL QUANTITY PROBE

For the electrical description and operation of the aftfuel quantity probe, refer to Chapter 96. For thedescription of the aft fuel quantity probe, refer toparagraph 28-9.

28-95. Aft Fuel Quantity Probe — Removal


2. Defuel the main fuel cell and the forward fuel cell(Chapter 12).

3. Drain the main fuel cell and the forward fuel cell(Chapter 12).


5. Remove the forward facing passenger seatcushions and seat backs (Chapter 25).

6. Remove the hat bin assembly panel(Chapter 25).

7. Remove the screws and washers from the mainfuel cell access panel and remove the panel from thefuel cell compartment.

8. Disconnect the electrical connector (1,Figure 28-19) from the receptacle on the aft fuelquantity probe (2).

9. Remove the screws (9), bolt (17), andwashers (10) from the retainer assembly (11).

10. Remove the retainer assembly (11) and theseal (13) from the aft fuel quantity probe (2). Discardthe seal.

11. Remove the aft fuel quantity probe (2) from themain fuel cell (8).

12. Remove the screw (5), washer (4), and nut (3)from the clamp (6).

13. Remove the clamp (6) from the aft fuel quantityprobe (2).


MATERIALS REQUIRED

NUMBER NOMENCLATURE

C-003 Turbine Fuel


MATERIALS REQUIRED

NUMBER NOMENCLATURE


BHT-407-MM-4


Figure 28-19. Aft Fuel Quantity Probe


DETAIL B DETAIL C

DETAIL A

SEE DETAIL A

SEE DETAIL B

SEE DETAIL C8

11

17

10

9

10

1213

2

1

16

14

7

15

34

6

5

1.2.3.4.5.6.7.8.9.

10.11.12.13.14.15.16.17.

ConnectorAft fuel quantity probeNutWasherScrewClampClampFuel cellScrewWasherRetainer assemblyPackingSealReceptaclePackingJam nutBolt

BHT-407-MM-4


14. Remove the jam nut (16) from thereceptacle (14).

15. Remove the receptacle (14) and packing (15)from the aft fuel quantity probe (2). Discard thepacking.

16. Remove the packing (15) from thereceptacle (14). Discard the packing.

17. Remove the packing (12) from the recess on themain fuel cell (8). Discard the packing.

18. Install caps and/or plugs (C-428) on the open portof the main fuel cell (8).

28-96. Aft Fuel Quantity Probe — Inspection

1. Examine the aft fuel quantity probe for signs ofexternal damage, pitting, and corrosion.

2. Examine the aft fuel quantity probe electricalconnector for signs of damage to the pins.

3. Examine the aft fuel quantity probe for eccentricbolt holes.

28-97. Aft Fuel Quantity Probe — Installation

1. Remove the caps and/or plugs from the port ofthe main fuel cell (8, Figure 28-19).

2. Examine the internal area of the main fuel cell (8)for signs of dirt and unwanted objects.

3. Apply a light layer of turbine fuel (C-003) on thepacking (12) and install the packing in the recess ofthe main fuel cell (8).

4. Apply a light layer of turbine fuel (C-003) on thepacking (15) and install the packing on thereceptacle (14).

5. Install the receptacle (14) on the aft fuel quantityprobe (2) and secure with the jam nut (16).

NOTE

Refer to Figure 28-21 for dimensionaldetails of installed clamping position.

6. Install the clamp (7, Figure 28-19) on the aft fuelquantity probe (2).

7. Position the fuel quantity harness (4,Figure 28-21) in the clamp (6, Figure 28-19).

8. Align the clamp (6) with the clamp (7), and securewith screw (5), washer (4), and nut (3).

9. Align the seal (13) on the aft fuel quantityprobe (2).

10. Align the retainer assembly (11) on the aft fuelquantity probe (2) and secure with the 16washers (10), screws (9), and bolt (17).


12. Connect the electrical connector (1) to thereceptacle (14) of the fuel quantity harness.

13. Fill the helicopter fuel system with turbine fuel(C-003) (Chapter 12) and examine the aft fuel quantityprobe (2) for signs of leaks.


15. Align the main fuel cell access panel and safetywith the washers and screws.

16. Install the hat bin panel assembly (Chapter 25).

17. Install the forward facing passenger seatcushions and seat backs (Chapter 25).

28-98. MID LEVEL FUEL QUANTITY PROBE

For the electrical description and operation of the midlevel fuel quantity probe, refer to Chapter 96. For thedescription of the mid level fuel quantity probe, refer toparagraph 28-9.


MATERIALS REQUIRED

NUMBER NOMENCLATURE

C-003 Turbine Fuel

BHT-407-MM-4


28-99. Mid Level Fuel Quantity Probe — Removal


2. Defuel the forward fuel and the main fuel cell(Chapter 12).




6. Disconnect the connector (1, Figure 28-20) fromthe receptacle on the mid level fuel quantity probe (3).

7. Remove the nut (9), washer (10) and screw (8)from the clamp (6).

8. Remove the clamp (7) from the mid level fuelquantity probe (3).

9. Remove the three bolts (4) and washers (5) fromthe mid level fuel quantity probe (3).

10. Remove the mid level fuel quantity probe (3) fromthe main fuel cell (2).

11. Install caps and/or plugs (C-428) on the open portof the main fuel cell (2).

28-100. Mid Level Fuel Quantity Probe —Inspection

1. Examine the mid level fuel quantity probe forsigns of external damage, pitting, and corrosion.

2. Examine the mid level fuel quantity probeelectrical receptacle for signs of damage to the pins.

3. Examine the mid level fuel quantity probe foreccentric bolt holes.

28-101. Mid Level Fuel Quantity Probe —Installation

1. Remove the caps and/or plugs from the open portof the main fuel cell (2, Figure 28-20).

2. Examine the internal area of the main fuel cell (2)for signs of dirt and unwanted objects. Make sure thefuel cell is clean.

3. Align the mid level fuel quantity probe (3) with thethree fuel probe mount inserts in the main fuel cell (2).

NOTE

Make sure the clamping arrangement (11)for the standpipe and fuel transfer tube issecured with the left-hand side positionedbolt.

4. Secure the mid level fuel quantity probe (3) to thethree inserts with the three washers (5) and bolts (4).Torque the bolts .

5. Connect the electrical connector (1) to thereceptacle on the mid level fuel quantity probe (3).

NOTE

Refer to Figure 28-21 for dimensionaldetails of installed clamping position.

6. Install the clamp (7) on the mid level fuel quantityprobe (3).

7. Align the clamp (6) with the clamp (7) and installwith the screw (8), washer (10), and nut (9).

8. Install the fuel boost pump assembly (paragraph28-53).


MATERIALS REQUIRED

NUMBER NOMENCLATURE

C-428 Caps and/or Plugs Refer to BHT-ALL-SPM for specifications.

MATERIALS REQUIRED

NUMBER NOMENCLATURE

C-003 Turbine Fuel

T

BHT-407-MM-4


Figure 28-20. Mid Level Fuel Quantity ProbeNO OBJECT BEYOND THIS POINT 407MM_28_0046

2

1.2.3.4.5.6.7.8.9.

10.11.

ConnectorMain fuel cellMid level fuel quantity probeScrewWasherClampClampScrewNutWasherClamping arrangement

1

4

5

9

3

7 108

6

40 IN-LBS MAX(4.52 Nm MAX)

11

BHT-407-MM-4


9. Fill the helicopter fuel system with turbine fuel(C-003) (Chapter 12) and examine for signs of leaks.


28-102. FUEL QUANTITY HARNESS

For the electrical description of the fuel quantityharness, refer to Chapter 96. For the description of thefuel quantity harness, refer to paragraph 28-9.

28-103. Fuel Quantity Harness — Removal

WARNING

JET FUEL IS EXTREMELY FLAMMABLE.FUEL FUMES AND GASSES CAN IGNITEWITH STATIC ELECTRICITY, FRICTIONSPARKS, HOT EXHAUST P IPES,LIGHTED CIGARETTES, ELECTRICALDEVICES, OR S IMILAR IGNIT IONSOURCES.

1. Make sure that the helicopter is grounded(Chapter 12) and that the battery and external poweris disconnected.





NOTE

To remove the fuel quantity harness (4,Figure 28-21) from the aft fuel quantityprobe (5), remove the aft fuel quantityprobe.

6. Remove the aft fuel quantity probe (paragraph28-95).

7. In main fuel cell (7), remove the nut (19), washer(20), and screw (21) from the clamp (12) as shown inDetail B.

8. Remove the nut (26), washers (27 and 28), andscrew (23) from the clamp (24) and bracket (25)(Detail C).

9. Remove the fuel quantity harness (4) from theclamp (24).

10. In forward fuel cell (16), remove the two nuts (19),washers (20), and screws (21) from the two clamps(17 and 18) as shown in Detail B.

11. Remove the two clamps (17 and 18) from the fuelquantity harness (4).

12. Disconnect the forward fuel quantity probeconnector (14) (1A3P1) from the receptacle on theforward fuel quantity probe (15).

NOTE

Attach a piece of cord (C-480) to theforward fuel quantity harnessconnector (14) (1A3P1). This will allowreinstallation of the wiring harness (4) backinto the forward fuel cell (16) after removal.

13. Attach a piece of cord (C-480) to the forward fuelquantity harness connector (14) (1A3P1).


MATERIALS REQUIRED

NUMBER NOMENCLATURE


C-480 Cord

BHT-407-MM-4


Figure 28-21. Fuel Quantity Harness (Sheet 1 of 2)407MM_28_0048

A

VIEW A

2

3

4

6

5

4

7 8

9

10

11

SEE DETAIL C

12

14

18

4

17

1615

13

3.0 IN.76.2 mm

3.5 IN.88.9 mm 2.0 IN.

50.8 mm

110.0 IN.254 mm

SEE DETAIL B

SEE DETAIL B

22

22

22

BHT-407-MM-4


Figure 28-21. Fuel Quantity Harness (Sheet 2 of 2)407MM_28_0049

DETAIL C

9

27

26

23

28

24

25

19

DETAIL B

20

22

18

21

17

12

6

Main fuel quantity probe connector (1A1P1)Aft wiring harness connector (1P6)Fuel quantity harness connector (1J6)Fuel quantity harnessAft fuel quantity probeClampMain fuel cellMid fuel quantity probe connector (1A2P1)StandpipeMid fuel quantity probeFuel feed lineClampFuel cell interconnect tubeForward fuel quantity probe connector (1A3P1)

1.2.3.4.5.6.7.8.9.

10.11.12.13.14.

Forward fuel quantity probeForward fuel cellClampClampNutWasherScrewClampScrewClampBracketNutWasherWasher

15.16.17.18.19.20.21.22.23.24.25.26.27.28.

BHT-407-MM-4


CAUTION

TO PREVENT DAMAGE TO ELECTRICALHARNESS CONNECTORS ONINSTALLAT ION AND REMOVAL,STANDPIPE (9) MAY HAVE TO BEREMOVED FROM MAIN FUEL CELLMOUNT PLATE (PARAGRAPH 28-69).

14. If applicable, disconnect the standpipe (9) fromthe main fuel cell (7) (paragraph 28-69).

15. Pull the fuel quantity harness (4) aft through thefuel cell interconnect tube (13) and standpipe (9).

NOTE

To allow reinstallation of the fuel quantityharness (4), leave the cord (C-480) inposition between the forward and main fuelcells (16 and 7).

16. Remove the cord from fuel quantity harness (4)and remove the harness from the main fuel cell (7).

17. Install caps and/or plugs (C-428) on forward andmain fuel cell openings.

28-104. Fuel Quantity Harness — Inspection

1. Examine the fuel quantity harness connectors (3,8, and 14, Figure 28-21) for signs of mechanical orcorrosion damage, and damage to the electrical pins.

2. Examine the fuel quantity harness (4) insulationtubing and wires for signs of cracks and chafing.

28-105. Fuel Quantity Harness — Installation

WARNING

JET FUEL IS EXTREMELY FLAMMABLE.FUEL FUMES AND GASSES CAN IGNITEWITH STATIC ELECTRICITY, FRICTIONSPARKS, HOT EXHAUST P IPES,LIGHTED CIGARETTES, ELECTRICALDEVICES, OR S IMILAR IGNIT IONSOURCES.

1. Remove caps and plugs from forward and mainfuel cell openings.

2. Examine interior of forward fuel cell (16,Figure 28-21) and main fuel cell (7) for dirt andunwanted material. Make sure the fuel cells are clean.

3. Position the fuel quantity harness (4) in the mainfuel cell (7).

4. Install the aft fuel quantity probe (5) and attachthe fuel quantity harness (4) (paragraph 28-97).

CAUTION

POSIT ION THE FUEL QUANTITYHARNESS (4) UNDER THE FUEL FEEDLINE (11) TO PREVENT CONTACT ANDCHAFING.

5. Make sure the fuel quantity harness (4) ispositioned under the fuel feed line (11).

CAUTION

TO PREVENT DAMAGE TO ELECTRICALHARNESS CONNECTORS ONINSTALLATION, THE STANDPIPE (9)MAY HAVE TO BE REMOVED FROM THEMAIN FUEL CELL MOUNT PLATE(PARAGRAPH 28-69).

6. In the main fuel cell (7), attach the cord (C-480) tothe forward fuel quantity probe connector (14) (1A3P1)and pull the harness forward through the standpipe (9)


MATERIALS REQUIRED

NUMBER NOMENCLATURE

C-480 Cord

BHT-407-MM-4


and the fuel cell interconnect tube (13) into the forwardfuel cell (16).

7. Remove the cord from the forward fuel quantityprobe connector (14) (1A3P1). Remove the cord fromthe forward fuel cell (16).

8. Connect the electrical connector (14) (1A3P1) tothe receptacle of the forward fuel cell fuel quantityprobe (15).

9. Install the two clamps (17 and 18) on the fuelquantity harness (4).

10. Locate the upper clamp (22) 3.5 inches(88.9 mm) from the top of the forward fuel quantityprobe (15).

11. Install clamp (18) on the upper clamp (22) withscrew (21), washer (20), and nut (19) as shown inDetail B.

12. Locate the lower clamp (22) 3.0 inches (76.2 mm)from the bottom of the forward fuel quantity probe (15).

13. Install clamp (17) on the lower clamp (22) withscrew (21), washer (20), and nut (19) as shown inDetail B.

14. If previously removed, install the standpipe (9)(paragraph 28-71).

15. Install the clamp (24) on the fuel quantityharness (4).

16. Install the clamp (24) on the bracket (25) with thescrew (23), washers (28 and 27), and nut (26).

CAUTION

POSIT ION THE FUEL QUANTITYHARNESS (4) UNDER THE FUEL FEEDLINE (11) TO PREVENT CONTACT ANDCHAFING.

17. Connect the mid fuel quantity probe connector (8)(1A2P1) to the receptacle of the mid fuel quantityprobe (10).

18. Make sure the fuel quantity harness (4) ispositioned under the fuel feed line.

19. Install the clamp (12) on the fuel quantityharness (4).

20. Locate the clamp (22) 2.0 inches (50.8 mm) fromthe bottom of the mid fuel quantity probe (10).

21. Install clamp (12) on the clamp (22) with thescrew (21), washer (20), and nut (19) as shown inDetail B.


23. Install the boost pump assembly (paragraph28-53.

24. Connect the battery or external power(Chapter 96).

25. Perform fuel quantity system calibration check(Chapter 95).

26. Examine the forward and main fuel cells (16and 7) for leaks.

28-106. MAIN FUEL CELL LOW LEVEL SWITCH

For the electrical description and operation of the mainfuel cell low level switch, refer to Chapter 96. For thedescription of the main fuel cell low level switch, referto paragraph 28-9.

28-107. Main Fuel Cell Low Level Switch —Removal





5. Remove the screw (8, Figure 28-22) andwasher (7) from the retainer (11).

BHT-407-MM-4


Figure 28-22. Main Fuel Cell Low Level Switch


BHT-407-MM-4

28-00-00

ECCN EAR99


7. Remove the retainer (11) and the two washers (6and 12) from the pump (1).

8. Disconnect the electrical terminals (13) from theconnector on the pump (1).

9. Remove the bolts (5) and washers (4) from theswitch (3).

10. Remove the switch (3) and packing (2) from thepump (1). Discard the packing.

28-108. Main Fuel Cell Low Level Switch —Inspection

1. Examine the main fuel cell low level switch forsigns of external damage, pitting, and corrosion.

2. Examine the main fuel cell low level switchelectrical lead for signs of chafing and cracks in theinsulation.

3. Examine the main fuel cell low level switch foreccentric bolt holes.

28-109. Main Fuel Cell Low Level Switch —Installation

1. Apply a light layer of turbine fuel (C-003) on thepacking (2, Figure 28-22) and install the packing onthe switch (3).

2. Install the switch (3) in the port of the pump (1).

3. Safety the switch (3) to the pump (1) with twowashers (4) and bolts (5).

4. Connect the electrical terminals (13) to theconnector on the pump (1).

5. Install the washer (7), screw (8), washer (10), andscrew (9) through the retainer (11).


7. Install the retainer (11) on the pump (1).


9. Fill the helicopter fuel system with turbine fuel(C-003) (Chapter 12) and examine the switch (3) forleaks.


MATERIALS REQUIRED

NUMBER NOMENCLATURE

C-003 Turbine Fuel

26 FEB 2010 Rev. 27 Page 67/68

407-MM-CH28

Documents

Transcript of 407-MM-CH28