Installation of the Center Tank Fuel-Quantity-Probe

TASK 28-42-15-400-002-A
Installation of the Center Tank Fuel-Quantity-Probe

WARNING: THIS PROCEDURE USES A FUEL SYSTEM ITEM THAT IS IN A CATEGORY KNOWN AS A CRITICAL DESIGN CONFIGURATION CONTROL LIMITATION (CDCCL). CDCCL IDENTIFIES AN ITEM THAT CAN BE THE SOURCE OF A POSSIBLE FUEL TANK IGNITION. YOU MUST KEEP ALL CDCCL ITEMS IN THE APPROVED CONFIGURATION. DAMAGE, WEAR OR CHANGES TO A CDCCL ITEM CAN CAUSE A POSSIBLE FUEL TANK EXPLOSION.

WARNING: MAKE SURE THAT THE FLIGHT CONTROL SAFETY-LOCKS AND THE WARNING NOTICES ARE IN POSITION.

WARNING: MAKE SURE THAT THE GROUND SAFETY-LOCKS ARE IN POSITION ON THE LANDING GEAR. THIS WILL PREVENT UNWANTED MOVEMENT OF THE LANDING GEAR, AND THUS POSSIBLE INJURY TO PERSONS AND DAMAGE TO THE AIRCRAFT AND/OR EQUIPMENT.

WARNING: BE CAREFUL WHEN YOU USE CONSUMABLE MATERIALS. OBEY THE MATERIAL MANUFACTURER'S INSTRUCTIONS AND YOUR LOCAL REGULATIONS.

FIN: 35QT ** ON A/C NOT FOR ALL
FIN: 36QT ** ON A/C NOT FOR ALL
FIN: 37QT ** ON A/C NOT FOR ALL
FIN: 38QT ** ON A/C NOT FOR ALL
FIN: 39QT ** ON A/C NOT FOR ALL

1. Reason for the Job
Self explanatory
2. Job Set-up Information
A. Fixtures, Tools, Test and Support Equipment

REFERENCE	QTY	DESIGNATION
No specific	AR	SAFETY BARRIER(S)
No specific	AR	WARNING NOTICE(S)

B. Consumable Materials

REFERENCE	DESIGNATION
(Material No.06ABB1)	Polysulfide Sealant-Fuel Tank Fillet -
(Material No.06ABF1)	Polysulfide Sealant-Fuel Tank Quick Curing -
(Material No.08BAA9)	Non Aqueous Cleaner-General - -
(Material No.14SBA1)	Textile-Lint free Cotton -

C. Expendable Parts

FIG.ITEM	DESIGNATION	IPC-CSN
8	CABLE TIE	AIPC 28-42-05-04-010
7	CABLE TIE	AIPC 28-42-05-04-020

D. Referenced Information

REFERENCE	DESIGNATION
TASK 12-11-28-650-003-A	Pressure Refuel with Automatic Control
TASK 28-10-00-910-001-A	Safety Procedures When You Do Work in a Fuel Tank
TASK 28-10-00-910-002-A	Access to the Fuel Tanks and the Work Areas
TASK 28-25-00-650-001-A	Pressure Defuel
TASK 28-25-00-650-003-A	To Drain Remaining Fuel from the Wing Tanks and the Center Tank
TASK 28-25-00-650-003-A-01	To Drain Remaining Fuel from the Wing Tanks and the Center Tank
TASK 28-25-00-869-001-A	Fuel Transfer
TASK 28-42-00-740-001-A	Status Report (BITE)
TASK 32-12-00-010-001-A	Open the Main Gear Doors for Access
TASK 32-12-00-410-001-A	Close the Main Gear Doors after Access
TASK 57-17-11-000-001-A	Removal of Access Cover 147AZ(148AZ)
TASK 57-17-11-400-001-A	Installation of Access Cover 147AZ(148AZ)
Center Tank Probes - Location and Detail

3. Job Set-up
Subtask 28-42-15-941-053-A ** ON A/C NOT FOR ALL

A. Safety Precautions

WARNING: BEFORE YOU DO WORK IN OR NEAR A FUEL TANK, MAKE SURE THAT YOU OBEY ALL THE SAFETY PROCEDURES. THIS WILL PREVENT INJURY TO PERSONS AND/OR DAMAGE TO THE AIRCRAFT.

(1) You must obey the fuel safety procedures (Ref. AMM TASK 28-10-00-910-001) when you do work in a fuel tank.
(2) Make sure that the SAFETY BARRIER(S) are in position.
(3) Make sure that the WARNING NOTICE(S) is in position to tell persons not to operate the MLG doors.

Subtask 28-42-15-860-052-A ** ON A/C NOT FOR ALL

B. Aircraft Maintenance Configuration
(1) Make sure that the applicable fuel tank is defueled (Ref. AMM TASK 28-25-00-650-001).
(2) Make sure that the remaining fuel has been drained from the applicable fuel tank (Ref. AMM TASK 28-25-00-650-003).
(3) Make sure that the applicable MLG door(s) is/are open (Ref. AMM TASK 32-12-00-010-001).
(4) Make sure that the 460005835 SLEEVE - GROUND LOCK is installed on the applicable MLG door actuator(s).
(5) Make sure that the access platform is below the applicable access panel 147AZ (148AZ).
(6) Make sure that the applicable access panel 147AZ (148AZ) is removed (Ref. AMM TASK 28-10-00-910-002), (Ref. AMM TASK 57-17-11-000-001).

Subtask 28-42-15-865-054-A ** ON A/C NOT FOR ALL

C. Make sure that this(these) circuit breaker(s) is(are) open, safetied and tagged:

PANEL	DESIGNATION	FIN	LOCATION
** ON A/C NOT FOR ALL
49VU	FUEL/FQI/CHAN/1	1QT	A13
121VU	FUEL/FQI/CHANNEL/1 AND 2	8QT	L26
121VU	FUEL/FQI/CHAN/2	2QT	M27

4. Procedure
Subtask 28-42-15-420-051-A ** ON A/C NOT FOR ALL

A. Preparation for Installation
(1) Clean the component interfaces and the adjacent areas with a Textile-Lint free Cotton - (Material No.14SBA1) made moist with Non Aqueous Cleaner-General - - (Material No.08BAA9) .
(2) Do an inspection of the component interfaces and the adjacent area.
(3) Make sure that the parts retained from the removed component are clean and in the correct condition.

Subtask 28-42-15-420-059-A ** ON A/C NOT FOR ALL

B. Installation of the Center-Tank-Fuel-Quantity-Probes

CAUTION: REFER TO THE MATCH MARKS MADE DURING THE REMOVAL WHEN YOU CONNECT THE ELECTRICAL WIRES. INCORRECT CONNECTION OF THE WIRES WILL CAUSE DAMAGE TO EQUIPMENT.

CAUTION: WHEN YOU INSTALL AN ELECTRICAL CABLE, YOU MUST PUSH THE PLASTIC HOUSING IN UNTIL YOU HEAR A CLICK. THIS WILL MAKE SURE THAT THE ELECTRICAL CABLE IS INSTALLED CORRECTLY.

(1) Put the probe (2) near its installed location then carefully move the top of the probe (2) into the support tube (1). Put the probe (2) in position.
(2) Hold the probe (2) and install the bolts (4) and the washers (5) and, for probes 35QT and 36QT, the nuts (6).
(3) Tighten the bolts (4).
(4) Measure the clearance between the structure and the top and the bottom of the probe (2).

WARNING: THIS INSTRUCTION IS APPLICABLE TO A CRITICAL DESIGN CONFIGURATION CONTROL LIMITATION (CDCCL) ITEM. CAREFULLY OBEY ALL GIVEN INSTRUCTIONS WHEN YOU DO THIS STEP. IF YOU DO NOT OBEY THESE INSTRUCTIONS, A DANGEROUS CONDITION CAN OCCUR THAT CAN CAUSE A POSSIBLE FUEL TANK EXPLOSION.

(a) Make sure that the clearance is a minimum of 10.0 mm (0.3937 in.).
(b) To prevent possible static discharge, make sure that the fuel probe is not less than 6.0 mm (0.2362 in.) from:

the nearest structure
rib and tank wall
pipework
brackets and p-clips
fasteners and other metal parts.

(5) Remove the blanking caps and connect the electrical cables (3) to the probe (2).
(6) Apply Polysulfide Sealant-Fuel Tank Fillet - (Material No.06ABB1) or Polysulfide Sealant-Fuel Tank Quick Curing - (Material No.06ABF1) to the ends of the bolt (4).
(7) Use the AIPC 28-42-05-04-020 CABLE TIE (7) and the AIPC 28-42-05-04-010 CABLE TIE (8) to attach the electrical cables (3) to the probe (2). Use the applicable tool, set to the minimum tension, to tighten the cable ties (7) and (8).

5. Close-up
Subtask 28-42-15-410-052-A ** ON A/C NOT FOR ALL

A. Close Access
(1) Make sure that the work area is clean and clear of tools and other items.
(2) Install the applicable access panel 147AZ(148AZ) (Ref. AMM TASK 57-17-11-400-001).
(3) Remove the access platform(s).

WARNING: MAKE SURE THAT THE TRAVEL RANGES OF THE LANDING GEAR ARE CLEAR.

(4) Close the applicable MLG door(s) (Ref. AMM TASK 32-12-00-410-001).

Subtask 28-42-15-865-055-A ** ON A/C NOT FOR ALL

B. Remove the safety clip(s) and the tag(s) and close this(these) circuit breaker(s):

PANEL	DESIGNATION	FIN	LOCATION
** ON A/C NOT FOR ALL
49VU	FUEL/FQI/CHAN/1	1QT	A13
121VU	FUEL/FQI/CHANNEL/1 AND 2	8QT	L26
121VU	FUEL/FQI/CHAN/2	2QT	M27

Subtask 28-42-15-740-051-A ** ON A/C NOT FOR ALL

C. Test
(1) Do a status report (BITE) of the FQI system (Ref. AMM TASK 28-42-00-740-001).

Subtask 28-42-15-650-056-A ** ON A/C NOT FOR ALL

D. Fuel Configuration
(1) Refuel, defuel or transfer fuel as necessary (Ref. AMM TASK 12-11-28-650-003), (Ref. AMM TASK 28-25-00-650-001) or (Ref. AMM TASK 28-25-00-869-001).

Subtask 28-42-15-942-051-A ** ON A/C NOT FOR ALL

E. Removal of Equipment
(1) Remove the safety barriers.
(2) Remove the WARNING NOTICE(S).
(3) Remove the ground support and maintenance equipment, the special and standard tools and all other items.

[Rev.10 from 2021] 2026.04.02 06:18:06 UTC