To Drain Remaining Fuel from the Wing Tanks and the Center Tank

TASK 28-25-00-650-003-A
To Drain Remaining Fuel from the Wing Tanks and 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.

WARNING: DO NOT SPILL FUEL ON THE ENGINES OR THE BRAKES. IF YOU SPILL FUEL ON ENGINES OR BRAKES THAT ARE HOT, IT CAN CAUSE FIRES.

1. Reason for the Job
To drain the remaining fuel with Tool 97A28002117002 (wing tanks and center tank) or with Tool 98A28104000002 (center tank only).
To drain the remaining fuel with Tool 98A28203000000, use TASK 28-25-00-650-003-A01.

NOTE: If you do this procedure regularly it can prevent microbiological contamination of the fuel tanks.

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

REFERENCE	QTY	DESIGNATION
No specific	AR	BLOWING EQUIPMENT - HOT AIR
No specific	AR	CONTAINER 10 L(2 1/2 USGAL)
No specific	1	PUMP - SUCTION (ATEX APPROVED)
No specific	AR	SAFETY BARRIER(S)
No specific	AR	WARNING NOTICE(S)
97A28002117002	1	TOOL-PURGING
98A28104000002	1	TOOL - PURGING

B. Work Zones and Access Panels

ZONE/ACCESS	ZONE DESCRIPTION
195BB, 196BB

C. Referenced Information

REFERENCE	DESIGNATION
TASK 28-00-00-910-001-A	Fuel Safety Procedures
TASK 32-00-00-481-001-A	Installation of the Safety Devices on the Landing Gears
Defuel Safety Area ** ON A/C NOT FOR ALL
Defuel Safety Area ** ON A/C NOT FOR ALL
To Drain Remaining Fuel ** ON A/C NOT FOR ALL
To Drain Remaining Fuel ** ON A/C NOT FOR ALL

3. Job Set-up
Subtask 28-25-00-941-053-B

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) As necessary, use the applicable SAFETY BARRIERS, specified by the operator's instructions and your local regulations.
(3) Make sure that the ground safety locks are installed on the landing gear (Ref. AMM TASK 32-00-00-481-001).
(4) On the panel 400VU:

make sure that the landing-gear control-lever 6GA is in the DOWN position
put a warning notice in position to tell persons not to operate the landing gear.

(5) Put WARNING NOTICE(S) in position to tell persons not to operate the landing gear doors.
(6) If the fuel temperature is less than -5 DEG.C (23.00 DEG.F) and/or the water drain valves are frozen, heat the drain valve areas with an approved BLOWING EQUIPMENT - HOT AIR.

NOTE: Do not apply unusually high force to open the water drain valve.

Subtask 28-25-00-010-070-B

B. Get Access
(1) For access to the center tank water drain valves, open the applicable access panels:

for water drain valve 94QM, open access panel 195BB
for water drain valve 95QM, open access panel 196BB.

4. Procedure
Subtask 28-25-00-650-063-B

A. To Drain Remaining Fuel with 97A28002117002 TOOL-PURGING (Tool A) or 98A28104000002 TOOL - PURGING (Tool B) (center tank only)

NOTE: You can use the 97A28002117002 TOOL-PURGING to drain the remaining fuel from the wing and center tanks, but does not prevent leaks. It is recommended that you use the 98A28104000002 TOOL - PURGING to drain the remaining fuel from the center tank.

(1) To drain the remaining fuel from the wing tanks and the center tank with the 97A28002117002 TOOL-PURGING (Tool A), do the procedure as follows:
(a) On the 97A28002117002 TOOL-PURGING, fully retract the nut (4), the screw (3) and the plunger assembly (1).
(b) Install the 97A28002117002 TOOL-PURGING. Put the hexagonal end of the bush (2) into the base plate of the applicable water drain valve.
(c) Turn the bush (2) through 30 DEG.
(d) Turn the nut (4) until it touches and seals against the wing surface.
(e) Put the end of the hose into the container.
(f) Hold the bush (2) and turn the screw (3) to the end of its travel. This causes the plunger (1) to open the drain valve and the fuel to flow.
(g) When the fuel flow stops, hold the bush (2) and turn the screw (3) until the drain valve closes.
(h) Turn the nut (4) until it is clear of the wing surface.
(i) Turn the bush (2) back through 30 DEG and remove the 97A28002117002 TOOL-PURGING from the applicable water drain valve.
(j) Examine the water drain valve for leakage. Leaks are not permitted.

NOTE: This step is very important because access to the center tank water drain valves 94QM and 95QM is not easy.

(2) To drain the remaining fuel from the center tank with the 98A28104000002 TOOL - PURGING (Tool B), do the procedure as follows:
(a) Install the 98A28104000002 TOOL - PURGING. Put the end of the plunger (5) into the hole in the base plate of the applicable water drain valve.
(b) Push the 98A28104000002 TOOL - PURGING up until the sealing ring (6) touches and seals against the bottom of the water drain valve.
(c) Push the drainer (7) up until the plunger (5) causes the drain valve to open and the fuel to flow. Hold the 98A28104000002 TOOL - PURGING in the up position to keep the drain valve open.
(d) When the fuel flow stops or the bottle of the 98A28104000002 TOOL - PURGING is full, carefully lower and remove the 98A28104000002 TOOL - PURGING. This causes the water drain valve to close.
(e) If necessary, empty the 98A28104000002 TOOL - PURGING bottle and do steps (b) thru (d) again until there is no fuel flow.
(f) Examine the water drain valve for leakage. Leaks are not permitted.

NOTE: This is very important because access to the center tank drain valves 94QM and 95QM is not easy.

(3) Suction Procedure:
(a) You must use an approved type of PUMP - SUCTION (ATEX APPROVED) (Tool A) for use on a fuel system.
(b) On the 97A28002117002 TOOL-PURGING, fully retract the nut (4), the screw (3) and the plunger assembly (1).

CAUTION: MAKE SURE THAT THE PLUNGER OF THE TOOL ALIGNS CORRECTLY WITH THE WATER DRAIN VALVE. INCORRECT ALIGNMENT OF THE TOOL CAN CAUSE:

THE WATER DRAIN VALVE TO STAY IN THE OPEN POSITION AFTER THE TOOL IS REMOVED
A FUEL LEAK.

(c) Put the hexagonal end of the bush (2) into the bottom of the water drain valve.
(d) Turn the bush (2) through 30 DEG.
(e) Turn the nut (4) until it touches and seals against the bottom skin.
(f) Attach the PUMP - SUCTION (ATEX APPROVED) to the hose.
(g) Put the outlet of the PUMP - SUCTION (ATEX APPROVED) into the CONTAINER 10 L(2 1/2 USGAL).
(h) Hold the bush (2) and turn the screw (3) clockwise to its stop. This causes the plunger (1) to open the drain valve and the fuel to flow into the PUMP - SUCTION (ATEX APPROVED).
(i) Start the PUMP - SUCTION (ATEX APPROVED).
(j) Continuously monitor the fuel flow into the CONTAINER 10 L(2 1/2 USGAL).
(k) When the fuel flow stops, turn the screw (3) counterclockwise to its stop.
(l) Stop the PUMP - SUCTION (ATEX APPROVED).
(m) Remove the PUMP - SUCTION (ATEX APPROVED) from the hose.
(n) Turn the nut (4) until it does not touch the bottom skin.
(o) Turn the hexagonal end of the bush (2) 30 DEG and remove the 97A28002117002 TOOL-PURGING from the bottom of the water drain valve.
(p) Examine the drain valve for leaks.
(q) Do this procedure at all of the water drain valves.

5. Close-up
Subtask 28-25-00-410-076-B

A. Close Access
(1) Make sure that the work area is clean and clear of tools and other items.
(2) Close the applicable access panels:

for water drain valve 94QM, close access panel 195BB
for water drain valve 95QM, close access panel 196BB.

Subtask 28-25-00-942-055-A

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

[Rev.10 from 2021] 2026.04.01 00:06:03 UTC