Deactivation of the Center Tank

TASK 28-21-00-040-002-A
Deactivation of the Center Tank

WARNING: PUT THE SAFETY DEVICES AND THE WARNING NOTICES IN POSITION BEFORE YOU START A TASK ON OR NEAR:

THE FLIGHT CONTROLS
THE FLIGHT CONTROL SURFACES
THE LANDING GEAR AND THE RELATED DOORS
COMPONENTS THAT MOVE.

MOVEMENT OF COMPONENTS CAN KILL OR CAUSE INJURY TO PERSONS AND/OR CAN CAUSE DAMAGE TO THE EQUIPMENT.

1. Reason for the Job

NOTE: This deactivation task is not related to an AFM-CDL/MMEL item.

NOTE: Refer to OEB 178/2 and 180/2 - Eaton Fuel Pump and Center Tank Deactivation.

2. Job Set-up Information
A. Fixtures, Tools, Test and Support Equipment

REFERENCE	QTY	DESIGNATION
No specific	AR	CAP - BLANKING
No specific	AR	SAFETY BARRIER(S)
No specific	AR	SAFETY CLIP - CIRCUIT BREAKER

B. Referenced Information

REFERENCE	DESIGNATION
TASK 28-00-00-910-001-A	Fuel Safety Procedures
TASK 28-11-00-600-011-A	Preservation of a Center Tank (Not in Use)
TASK 28-21-00-040-002-A	Deactivation of the Center Tank
TASK 28-21-00-440-002-A	Reactivation of the Center Tank
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
Refuel Valve 10QU - Electrical connector
Fuel Pump 37QA(38QA) - Electrical connector

3. Job Set-up
Subtask 28-21-00-941-084-A ** ON A/C NOT FOR ALL

A. Safety Precautions

WARNING: OBEY THE FUEL SAFETY PROCEDURES.

(1) You must obey the fuel safety procedures when you do work on the fuel system (Ref. AMM TASK 28-00-00-910-001).
(2) Put the SAFETY BARRIER(S) in position.

Subtask 28-21-00-650-064-A ** ON A/C NOT FOR ALL

B. Fuel Configuration
(1) Defuel the center tank (Ref. AMM TASK 28-25-00-650-001).

Subtask 28-21-00-865-075-A ** ON A/C NOT FOR ALL

C. Open, safety and tag this(these) circuit breaker(s):

PANEL	DESIGNATION	FIN	LOCATION
** ON A/C NOT FOR ALL
FOR FIN: 37QA (PUMPFUEL NO 1, CTR TK)
121VU	FUEL/CTR TK/PUMP1 SPLY	29QA	P23
FOR FIN: 38QA (PUMPFUEL NO 2, CTR TK)
121VU	FUEL/CTR TK/PUMP2 SPLY	30QA	P26

4. Procedure
Subtask 28-21-00-040-051-A ** ON A/C NOT FOR ALL

A. Deactivation of the Center Tank

Refuel Valve 10QU - Electrical connector ** ON A/C NOT FOR ALL

Fuel Pump 37QA(38QA) - Electrical connector ** ON A/C NOT FOR ALL

(1) Disconnect the electrical connector (1) from the center tank refuel valve 10QU.
(2) Put a CAP - BLANKING on the electrical connector and safety the connector to the adjacent structure.
(3) Disconnect the electrical connector (2) from the center tank pumps 37QA(38QA).
(4) Put CAP - BLANKING on the electrical connectors and safety the connectors to the adjacent structure.
(5) Make an entry in the aircraft technical log that the center tank has been deactivated.

5. Close-up
Subtask 28-21-00-650-065-A ** ON A/C NOT FOR ALL

A. Fuel Configuration
(1) Drain the remaining fuel from the center tank (Ref. AMM TASK 28-25-00-650-003).

NOTE: It is recommended that you regularly do a water drain procedure on the deactivated center tank. This should be done at 36 hour intervals to prevent contamination/corrosion of the center tank.

NOTE: If the center tank is deactivated for more than 100 days or 800 flight hours/400 flight cycles, you must:

reactivate the center tank (Ref. AMM TASK 28-21-00-440-002)
do the Preservation of the Center Tank (Not in Use) procedure (Ref. AMM TASK 28-11-00-600-011)
deactivate the center tank again (Ref. AMM TASK 28-21-00-040-002).

Subtask 28-21-00-942-090-A ** ON A/C NOT FOR ALL

B. 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 07:02:20 UTC