Functional Check for Leakage of the Vent/Transfer Inner Pipes and the ACT(s) Bladder

TASK 28-28-00-790-802-A
Functional Check for Leakage of the Vent/Transfer Inner Pipes and the ACT(s) Bladder

WARNING: OBEY THE FUEL SAFETY PROCEDURES.

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: WHEN YOU USE COMPRESSED AIR:

USE THE CORRECT PROTECTION (FACE SHIELD OR GOGGLES)
DO NOT POINT THE AIRFLOW AT YOURSELF OR OTHER PERSONS.

LOOSE PARTICLES AND/OR HIGH PRESSURE AIR CAN CAUSE INJURY.

ZONE: 130
ZONE: 147
ZONE: 150
ZONE: 190
ZONE: 210
ZONE: 251

1. Reason for the Job
Refer to the MPD TASK: 282800-24
FUNCTIONAL CHECK FOR LEAKAGE OF THE VENT/TRANSFER INNER PIPES AND THE ACT(S) BLADDER.

NOTE: Two persons are necessary for this procedure.

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

REFERENCE	QTY	DESIGNATION
No specific	AR	ACCESS PLATFORM 2M (6 FT)
No specific	AR	FLASHLIGHT
No specific	AR	SAFETY CLIP - CIRCUIT BREAKER
No specific	AR	WARNING NOTICE(S)
98D28108559000	AR	ADAPTER - TUBE, DRAIN VALVE
98D28108562000	AR	ADAPTER, PRESSURE DRAIN - ACT
98D28108658000	1	TOOL-PRESSURE TEST,ACT

B. Work Zones and Access Panels

ZONE/ACCESS	ZONE DESCRIPTION
130	FWD CARGO COMPT AFT BULKHEAD OF AVNCS COMPT TO FWD PRESSURE BULKHEAD OF WING CENTER BOX
147	MAIN GEAR WELL AND HYDRAULIC COMPARTMENT
150	AFT CARGO COMPARTMENT FWD PRESS BULKHEAD TO AFT BULKHEAD OF AFT CARGO COMPARTMENT
190	BELLY FAIR, AIR CONDITIONING & HYD COMPT
210	CKPT,FWD COMPT BHD TO FLT COMPT BULKHEAD
251	AFT PASSENGER COMPARTMENT
148AZ, 151NC, 192MB, 195BB

C. Referenced Information

REFERENCE	DESIGNATION
TASK 24-41-00-861-002-A	Energize the Aircraft Electrical Circuits from the External Power
TASK 24-41-00-861-002-A-01	Energize the Aircraft Electrical Circuits from the APU
TASK 24-41-00-861-002-A-02	Energize the Aircraft Electrical Circuits from Engine 1(2)
TASK 24-41-00-862-002-A	De-energize the Aircraft Electrical Circuits Supplied from the External Power
TASK 24-41-00-862-002-A-01	De-energize the Aircraft Electrical Circuits Supplied from the APU
TASK 24-41-00-862-002-A-02	De-energize the Aircraft Electrical Circuits Supplied from the Engine 1(2)
TASK 25-55-11-000-002-A	Removal of the Ceiling Panels in the Aft Cargo-Compartment - FR47/FR59
TASK 25-55-11-400-002-A	Installation of the Ceiling Panels in the Aft Cargo-Compartment - FR47/FR59
TASK 28-00-00-910-001-A	Fuel Safety Procedures
TASK 28-11-47-000-802-A	Removal of the Additional Center Tank (ACT) Outer Drain-Valve
TASK 28-11-47-400-802-A	Installation of the Additional Center Tank (ACT) Outer Drain-Valve
TASK 28-25-00-650-001-A	Pressure Defuel
TASK 28-25-00-650-005-A	To Drain the Remaining Fuel from the Additional Center Tank (ACT)
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 33-14-00-710-001-A	Operational Check of the Light Test System
TASK 52-30-00-860-001-A	Open the FWD or Aft Cargo-Compartment Door with the Yellow Electric Pump
TASK 52-30-00-860-002-A	Close the FWD or Aft Cargo-Compartment Door with the Yellow Electric Pump
Access To Test Ports T1 and T2
Test-Tool Arrangement ACT
ACT Vent-Valve-Actuator (91QH) and ACT Fuel-Transfer-Valve Actuator (6QH) Position Indicator

3. Job Set-up
Subtask 28-28-00-860-259-A ** ON A/C NOT FOR ALL

A. Aircraft Maintenance Configuration
(1) Obey the fuel safety procedures (Ref. AMM TASK 28-00-00-910-001).
(2) Energize the aircraft electrical circuits
(Ref. AMM TASK 24-41-00-861-002).
(3) Defuel all the Additional Center Tanks (ACT(s)) (Ref. AMM TASK 28-25-00-650-001).
(4) Drain the remaining fuel from the applicable ACT(s) (Ref. AMM TASK 28-25-00-650-005).
(5) Open access door 192MB.
(6) Open refuel/defuel control panels 800VU and 801VU and make sure that:

The MODE SELECT switch is in the OFF position
All the REFUEL VALVE switches are in the NORM position.

(7) Put a WARNING NOTICE(S) in position to tell persons not to operate the refuel/defuel system:

On refuel/defuel control panels 800VU and 801VU.

(8) Close access door 192MB.
(9) In the cockpit, on FUEL control panel 40VU and ACT FUEL control panel 28VU:

Put the WARNING NOTICE(S) in position to tell persons not to operate the refuel/defuel system.

Subtask 28-28-00-865-203-A ** ON A/C NOT FOR ALL

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

PANEL	DESIGNATION	FIN	LOCATION
** ON A/C NOT FOR ALL
121VU	FUEL/ACT/FUEL PUMP/SPLY	25QH	Q29
FOR FIN: 93QH
121VU	FUEL/ACT VENT VLV/MAN/SPLY	62QH	L21
121VU	FUEL/ACT VENT VLV/AUTO/SPLY	61QH	L20

Subtask 28-28-00-860-274-A ** ON A/C NOT FOR ALL

C. Aircraft Maintenance Configuration
(1) In the cockpit:
(a) Do the operational test of the annunciator light test-system (Ref. AMM TASK 33-14-00-710-001):

Make sure that all the lights on ACT control panel 28VU are in the ON position during the test.

(b) On ACT FUEL control panel 28VU:
1 Make sure that the ACT XFR rotary switch is in the OFF position.
2 Push the MOD SEL pushbutton switch for the MAN mode:

Make sure that the MAN legend is in the ON position.

3 Push the "ALL ACT" pushbutton switch:

Make sure that the ISOL legend is in the ON position.

4 Set the ACT XFR rotary switch in AFT1 position.

NOTE: ACT vent-valve-actuator 91QH closes, ACT fuel-inlet-valve-actuator 94QH1 opens, ACT fuel-transfer-valve-actuator 6QH closes, ACT air-shut-off valve actuator (90QH) and forward-vent isolation-valve actuator 93QH (if the ACT FWD is installed) is open at this time.

Subtask 28-28-00-010-131-A ** ON A/C NOT FOR ALL

D. Get Access
(1) Open the left Main Landing Gear (MLG) door for access (Ref. AMM TASK 32-12-00-010-001).
(2) Put an ACCESS PLATFORM 2M (6 FT) in position in the left MLG bay.
(3) Open access door 195BB to get access to ACT vent-valve actuator [91QH] .
(4) Open the aft cargo-compartment door (Ref. AMM TASK 52-30-00-860-001).
(5) Remove ceiling panel 151NC to get access to test ports T1 and T2 (Ref. AMM TASK 25-55-11-000-002)

Access To Test Ports T1 and T2 ** ON A/C NOT FOR ALL

(6) On the lower fuselage:

Remove the water drain-valve service-panel to get access to the water drain valve below the applicable ACT.

4. Procedure
Subtask 28-28-00-860-260-B ** ON A/C NOT FOR ALL

A. Preparation for the Test

Access To Test Ports T1 and T2 ** ON A/C NOT FOR ALL

Test-Tool Arrangement ACT ** ON A/C NOT FOR ALL

(1)

ACT Vent-Valve-Actuator (91QH) and ACT Fuel-Transfer-Valve Actuator (6QH) Position Indicator ** ON A/C NOT FOR ALL

Use the FLASHLIGHT and make sure that the indication for the ACT vent-valve actuator (91QH) is in the closed position.

(2)

ACT Vent-Valve-Actuator (91QH) and ACT Fuel-Transfer-Valve Actuator (6QH) Position Indicator ** ON A/C NOT FOR ALL

Use the FLASHLIGHT and make sure that the indication for the ACT fuel-transfer-valve actuator (6QH) is in the closed position.

(3) On the lower fuselage:
(a) Remove the ACT outer water-drain-valve from ACT AFT1 (Ref. AMM TASK 28-11-47-000-802).
(b) Remove the safety clip(s) and the tag(s) and close this(these) circuit breaker(s):

61QH
62QH.

(c) Make sure that the 98D28108559000 ADAPTER - TUBE, DRAIN VALVE is installed in the correct position.
(d) Connect the 98D28108562000 ADAPTER, PRESSURE DRAIN - ACT to the ACT water drain-valve of ACT AFT1.
(4) In the aft cargo compartment:
(a) Connect the 98D28108658000 TOOL-PRESSURE TEST,ACT to test port T2.

NOTE: For this test, hose T1 is connected to test port T2 as an alternative of the test port shown on its label. Hose T2 is not connected during this test.

Subtask 28-28-00-790-060-A ** ON A/C NOT FOR ALL

WARNING: WHEN YOU USE COMPRESSED AIR:

USE THE CORRECT PROTECTION (FACE SHIELD OR GOGGLES)
DO NOT POINT THE AIRFLOW AT YOURSELF OR OTHER PERSONS.

LOOSE PARTICLES AND/OR HIGH PRESSURE AIR CAN CAUSE INJURY.

CAUTION: DURING THE ACT PRESSURIZATION, MAKE SURE THAT PERSONNEL ALWAYS MONITOR THE PROCEDURE TO PREVENT OVERPRESSURE. IF YOU DO NOT OBEY THIS INSTRUCTION, DAMAGE TO THE OVER PRESSURE PROTECTOR BURST DISC CAN OCCUR.

CAUTION: BE CAREFUL WHEN YOU PRESSURIZE THE TEST PORT T2. THE MAXIMUM PRESSURE MUST NOT BE MORE THAN 552 MBAR (8 PSI). IF YOU DO NOT OBEY THIS CAUTION, DAMAGE TO THE OVERPRESSURE PROTECTOR BURST DISC CAN OCCUR.

B. Functional Check for the Leakage of the Vent/Transfer Inner Pipes and the ACT(s) Bladder

ACTION	RESULT
1.Slowly pressurize test port T2 to between 345 mbar (5.0 psi) and 449 mbar (6.5 psi). NOTE: It can take approximately 30 minutes to pressurize the ACT(s)	NOTE: On the pressure gage at test port T2, the air pressure increases to between 345 mbar (5.0 psi) and 449 mbar (6.5 psi). On the pressure gage at the water-drain-valve interface: The indicator shows the pressure between 345 mbar (5.0 psi) and 449 mbar (6.5 psi).
2.Stop the pressurization.	The pressure stays constant for more than 15 minutes. NOTE: If the pressure in the system is more than 552 mbar (8.0 psi): The ACT pressure holding-valves will open at 664 mbar (9.6 psi) The burst discs of the ACT vent system will break at 830 mbar (12.0 psi).
	If the pressure at the water-drain valve interface does not stay constant for 15 minutes, find the leak(s).
	There are no leaks permitted. If there are leaks, do an approved repair (Refer to DFPRM (Duct and Fuel-Pipe Repair Manual)) and do this test again.
3.Slowly release the air pressure from test port T2.
4.On ACT FUEL control panel 28VU: 5.Set the "ACT XFR" rotary switch to "OFF" position. 6.Release the "ALL ACT" PBS/W: Make sure that the "ISOL" legend is off. 7.Release the "MOD SEL" PBS/W: Make sure that the "MAN" legend is off. NOTE: The ACT vent-valve actuator [91QH] opens.	At the interface of the water drain valves and at test port T2: The pressure decreases to 0 mbar (0.0 psi). NOTE: It is necessary to make sure that no persons are inside the center tank. The pressure will be released into the center tank and can cause damage to persons.

Subtask 28-28-00-860-244-B ** ON A/C NOT FOR ALL

C. Put the system back to the serviceable condition.
(1) In the aft cargo compartment:
(a) Disconnect the 98D28108658000 TOOL-PRESSURE TEST,ACT from test port T2.
(2) On the lower fuselage:
(a) Disconnect the 98D28108562000 ADAPTER, PRESSURE DRAIN - ACT from the ACT water drain-valve of ACT AFT1.
(b) Open, safety and tag this(these) circuit breaker(s):

61QH
62QH.

ACT Vent-Valve-Actuator (91QH) and ACT Fuel-Transfer-Valve Actuator (6QH) Position Indicator ** ON A/C NOT FOR ALL

Use the FLASHLIGHT and make sure that the indication for the ACT fuel-transfer-valve actuator (6QH) shows the open position.

(4)

ACT Vent-Valve-Actuator (91QH) and ACT Fuel-Transfer-Valve Actuator (6QH) Position Indicator ** ON A/C NOT FOR ALL

Use the FLASHLIGHT and make sure that the indication for the ACT vent-valve actuator (91QH) shows the open position.

5. Close-up
Subtask 28-28-00-410-092-A ** ON A/C NOT FOR ALL

A. Close Access
(1) On the lower fuselage, install the water-drain valve service-panel below the ACT.
(2) Install access panel 151NC to close access to test ports T1 and T2 (Ref. AMM TASK 25-55-11-400-002).
(3) Close the aft cargo-compartment door (Ref. AMM TASK 52-30-00-860-002).
(4) Close access door 195BB.
(5) Remove the access platform(s).
(6) Close the left MLG doors after access (Ref. AMM TASK 32-12-00-410-001).

Subtask 28-28-00-865-204-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
121VU	FUEL/ACT/FUEL PUMP/SPLY	25QH	Q29
FOR FIN: 93QH
121VU	FUEL/ACT VENT VLV/MAN/SPLY	62QH	L21
121VU	FUEL/ACT VENT VLV/AUTO/SPLY	61QH	L20

Subtask 28-28-00-860-261-A ** ON A/C NOT FOR ALL

C. Put the aircraft back to its initial configuration.
(1) Remove the WARNING NOTICE(S).
(2) Remove the ground support and maintenance equipment, the special and standard tools and all other items.
(3) De-energize the aircraft electrical circuits
(Ref. AMM TASK 24-41-00-862-002).

[Rev.10 from 2021] 2026.04.02 06:17:53 UTC