Definitive Leak Test of the Dry Bay - Without Fuel - Helium Procedure

TASK 28-11-00-790-803-A
Definitive Leak Test of the Dry Bay - Without Fuel - Helium Procedure

WARNING: MAKE SURE THAT THE SAFETY DEVICES AND THE WARNING NOTICES ARE IN POSITION BEFORE YOU START A TASK ON OR NEAR:

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

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

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

1. Reason for the Job
The following tooling is supplied by Sunaero and is required for this procedure.
TPS800DBA320-----Tank Pressurization System
DET-CP-HS-M006---Helitest Leak Detector with Safety Probe
DET-CP-HX-N001---Helitest Pro (ATEX Approved)
DETHECPATEX------Helitest Atex
DET-KIT-DB320-PR00--Dry Bay Permanent Repair Full Kit (IPS, Interface, Detector)
2. Job Set-up Information
A. Fixtures, Tools, Test and Support Equipment

REFERENCE	QTY	DESIGNATION
No specific	1	ACCESS PLATFORM 2M (6 FT)
No specific	1	AIR SOURCE 0.3 TO 0.7 BAR (5 TO 10 PSI)- FILTERED, DRY
No specific	AR	SAFETY BARRIER(S)
No specific	AR	WARNING NOTICE(S)
DETHECPATEX	1	HELITEST ATEX
TPS800DBA320	1	TANK PRESSURIZATION SYSTEM FOR A320 DRY BAY

B. Consumable Materials

REFERENCE	DESIGNATION
No specific	05-RAB9

C. Work Zones and Access Panels

ZONE/ACCESS	ZONE DESCRIPTION
521AB, 521AZ, 521BZ, 540BB, 621AB, 621AZ, 621BZ, 640BB

D. Referenced Information

REFERENCE	DESIGNATION
TASK 12-11-28-650-003-A	Pressure Refuel with Automatic Control
TASK 27-50-00-866-008-A	Extension of the Flaps on the Ground
TASK 27-50-00-866-008-A-01	Extension of the Flaps/Slats on the Ground
TASK 27-50-00-866-009-A	Retraction of the Flaps on the Ground
TASK 27-50-00-866-009-A-01	Retraction of the Flaps/Slats on the Ground
TASK 28-10-00-910-001-A	Safety Procedures When You Do Work in a Fuel Tank
TASK 28-11-00-790-002-A	Leak Test with Fuel of the Wing-Tank Outer and Inner Cells
TASK 28-11-00-790-802-A	Leak Test of the Wing Tanks and the Center Tank - Without Fuel - Pressurized Air and Helium/Air Procedure
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 28-43-21-000-001-A	Removal of the Magnetic Level-Indicator Rod
TASK 28-43-21-400-001-A	Installation of the Magnetic Level-Indicator Rod
TASK 51-76-12-300-001-A	Local Repair of the Fuel Tank Sealant
TASK 57-27-11-000-001-A	Removal of the Access Panel
TASK 57-27-11-000-005-A	Removal of the Access Panel
TASK 57-27-11-400-001-A	Installation of the Access Panel
TASK 57-27-11-400-005-A	Installation of the Access Panel
TASK 57-27-11-400-005-C	Installation of the Access Panel
TASK 57-27-11-400-005-D	Installation of the Access Panel
TASK 57-27-11-400-005-E	Installation of the Access Panel
TASK 57-41-37-000-004-A	Removal of the Pressure Relief Panels
TASK 57-41-37-400-002-A	Installation of the Pressure Relief Panels
TASK 57-29-00-00	MISCELLANEOUS - DESCRIPTION AND OPERATION
Helium Mapping - Dry Bay Connection ** ON A/C NOT FOR ALL
Helium Mapping - Dry Bay Connection ** ON A/C NOT FOR ALL

3. Job Set-up
Subtask 28-11-00-941-120-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 when you do work in a fuel tank (Ref. AMM TASK 28-10-00-910-001).
(2) Put a WARNING NOTICE(S) in the cockpit to tell persons not to operate the flight controls.
(3) Put the SAFETY BARRIER(S) in position.

Subtask 28-11-00-860-131-A ** ON A/C NOT FOR ALL

B. Aircraft maintenance Configuration
(1) Defuel the applicable fuel tank (Ref. AMM TASK 28-25-00-650-001).
(2) Drain the remaining fuel from the applicable fuel tank (Ref. AMM TASK 28-25-00-650-003).
(3) Ventilate the applicable fuel tank.
(4) Extend the flaps & slats fully (Ref. AMM TASK 27-50-00-866-008).

Subtask 28-11-00-865-135-A ** ON A/C NOT FOR ALL

C. Open this(these) circuit breaker(s):

PANEL	DESIGNATION	FIN	LOCATION
** ON A/C NOT FOR ALL
121VU	FUEL/L WING TK/PUMP2 SPLY	7QA	N26
121VU	FUEL/L WING TK/PUMP1 SPLY	1QA	N23
121VU	FUEL/R WING TK/PUMP2 SPLY	8QA	Q26
121VU	FUEL/R WING TK/PUMP1 SPLY	2QA	Q23
** ON A/C NOT FOR ALL
121VU	FUEL/CTR TK/AUTO/CTL	3QL	R27
121VU	FUEL/CTR TK/L&R XFR/CTL & IND	2QL	R26
121VU	FUEL/CTR TK/L&R XFR/CTL & IND	1QL	R25
** ON A/C NOT FOR ALL
123VU	L WING TK/PUMP 1/STBY SPLY	11QA	AD12
123VU	R WING TK/PUMP 1/STBY SPLY	12QA	AE12

Subtask 28-11-00-010-093-A ** ON A/C NOT FOR ALL

D. Get Access
(1) Put the access platform ACCESS PLATFORM 2M (6 FT) in position below the applicable access panels.
(2) Remove pressure relief panels 521AB ( 621AB) (Ref. AMM TASK 57-41-37-000-004).
(3) Remove applicable fuel-tank access panels 540BB ( 640BB) (Ref. AMM TASK 57-27-11-000-001).
(4) Remove magnetic fuel-level gage 106QM (107QM) which is between the manhole and the dry bay (Ref. AMM TASK 28-43-21-000-001).
(5) Remove dry bay access-panels 521AZ ( 621AZ) and 521BZ ( 621BZ) (Ref. AMM TASK 57-27-11-000-005).

Subtask 28-11-00-869-080-A ** ON A/C NOT FOR ALL

E. Preparation of the Tank

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.

(1) Blow clean, filtered air from an AIR SOURCE 0.3 TO 0.7 BAR (5 TO 10 PSI)- FILTERED, DRY through the tank as follows:
(a) Put the air compressor as far as possible from the aircraft.
(b) Start the compressor and make sure that the air flows through the tank.
(c) Put the end of the compressor supply hose into the tank through an access panel hole.
(d) Make sure that the suction is from the bottom of the tank.
(e) Continue the air flow for six hours. One person must stay in the area to make sure that the process continues correctly.
(2) Make sure that the fuel-gas concentration is less than 3% of the Lower Explosion Limit (LEL).
(3) Make sure that the oxygen level is between 19% to 21% at different locations of the fuel tank.
(4) Make sure that the ducting is correct. This will prevent the loss of performance.
(5) Make sure that the work area is clear of removed air from the fuel tank.

Subtask 28-11-00-480-074-A ** ON A/C NOT FOR ALL

F. Installation of the Dry Bay Interfaces

NOTE: If a temporary repair has been done, deseal the area of the temporary repair.

(1) Install the interfaces to close the dry bay in this order:
(a) Track 4 hole interface (2)
(b) Access panel 1 interface (1).
(2) Apply aluminium tape 05-RAB9 on the drain holes of the dry bay.

NOTE: According to the A/C, the number and the design of drain holes may differ (Ref. AMM D/O 57-29-00-00).

(3) Apply aluminium tape 05-RAB9 on the access panel 2 (3) if the interfaces are not installed (optional).

Subtask 28-11-00-480-076-A ** ON A/C NOT FOR ALL

G. Installation of the IPS (see user technical documentation)
(1) Connect the electrical power to the control panel (3), switch to the ON position.
(2) Connect the compressed air source (dry and filtered) to the control panel (3).

NOTE: Pressure 2 bar (29.0075 psi).

(3) Connect the helium source (industrial quality) to the control panel (3). You can use the regulator kit is you have it.

NOTE: Pressure 5 bar (72.5189 psi).

(4) Connect the filling line to the control panel (3) and the access panel 1 interface (1).
(5) Connect the measuring line to the control panel (3) and to the access panel 1 interface (1).

4. Procedure
Subtask 28-11-00-790-101-A ** ON A/C NOT FOR ALL

A. Leak Test in the Dry Bay
(1) Do an air leak test as follows:
(a) Turn on the TPS800DBA320 TANK PRESSURIZATION SYSTEM FOR A320 DRY BAY.
(b) Operate the control panel (3), select pressurization function with air and start the test.

NOTE: The system will automatically increase the pressure to 0.10 bar (1.4504 psi).

(c) When the pressure is 0.10 bar (1.4504 psi), monitor the pressure in the dry bay for a period of 10 minutes.
(d) Make sure that the dry bay interfaces are airtight and correctly installed:
1 To make sure that the dry bay interfaces are airtight and correctly installed, you can listen for the hissing sounds or use bubble liquid to find the leak.
(e) If the dry bay interfaces are not airtight, purge and install the dry bay interfaces again until there are no leaks.
(f) When the dry bay interfaces are airtight, do a leak test with bubble liquid on the wet side of the dry bay. If you find a leak, make a match mark and clog it.

NOTE: To maintain the pressure in the dry bay, you can select maintain function on the control panel (3).

(2) Do a 1% helium concentration leak-test as follows:
(a) Select the pressurization function on the control panel (3) with helium and start the process:
1 Adjust the concentration of the helium to 1% (refer to manufacturer technical documentation).
(b) Select the pressurization function on the control panel (3) with air and continue.
(c) Wait for a period of 10 minutes to let the helium mix with the air in the dry bay.

NOTE: To maintain the pressure in the dry bay, you can select maintain function on the control panel (3).

(d) Do a leak check with an ATEX helium detector on the inner surfaces of the fuel tank to find the internal leak point. You can use one of the leak detector references that follow to do the leak check:

HELITEST LEAK DETECTOR with SAFETY PROBE
HELITEST PRO (DET-CP-HX-N001)
DETHECPATEX HELITEST ATEX.

NOTE: Fuel leaks can move along the aircraft structure.

1 Move the ATEX helium detector along the adjacent stringers and ribs.
2 Do this until the exit of the helium is found.
(e) If you find a leak, make a match mark and clog it.
(3) Do a 10% helium concentration leak-test as follow:
(a) Select the pressurization function on the control panel (3) with helium and start the process:
1 Adjust the concentration of helium to 10%.
(b) Wait for a few minutes to let the helium mix with the air in the dry bay.

NOTE: To maintain the pressure in the dry bay, you can select maintain function on the control panel (3).

(c) Do a leak check with an ATEX helium detector on the inner surfaces of the fuel tank to find the internal leak point. You can use one of the leak detector references that follow to do the leak check:

HELITEST LEAK DETECTOR with SAFETY PROBE
HELITEST PRO (DET-CP-HX-N001)
DETHECPATEX HELITEST ATEX.

NOTE: Fuel leaks can move along the aircraft structure.

1 Move the ATEX helium detector along the adjacent stringers and ribs.
2 Do this until the exit of the helium is found.
(d) Make a match mark when you find the leak.
(4) Operate the control panel (3) to purge the dry bay.
(5) Turn off the TPS800DBA320 TANK PRESSURIZATION SYSTEM FOR A320 DRY BAY.

Subtask 28-11-00-080-070-A ** ON A/C NOT FOR ALL

B. Removal of the IPS and Dry Bay Interfaces
(1) Removal of the IPS
(a) Disconnect the measuring line from the control panel (3) and from the access panel 1 interface (1).
(b) Disconnect the filling line from the control panel (3) and from the access panel 1 interface (1).
(c) Disconnect the helium source from the control panel (3).
(d) Disconnect the compressed air source from the control panel (3).
(e) Disconnect the electrical power from the control panel (3).
(2) Removal of the Dry Bay Interfaces
(a) Remove the following interfaces:

Access panel 1 interface (1)
Track 4 hole interface (2).

(b) Remove the aluminium tape (material No 05-RAB9) from the drain holes of the dry bay.
(3) Repair the leak as per (Ref. AMM TASK 51-76-12-300-001) and SRM 517612.
(4) Quality control of the repair as per (Ref. AMM TASK 28-11-00-790-002) and (Ref. AMM TASK 28-11-00-790-802).

5. Close-up
Subtask 28-11-00-865-136-A ** ON A/C NOT FOR ALL

A. 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/L WING TK/PUMP2 SPLY	7QA	N26
121VU	FUEL/L WING TK/PUMP1 SPLY	1QA	N23
121VU	FUEL/R WING TK/PUMP2 SPLY	8QA	Q26
121VU	FUEL/R WING TK/PUMP1 SPLY	2QA	Q23
** ON A/C NOT FOR ALL
121VU	FUEL/CTR TK/AUTO/CTL	3QL	R27
121VU	FUEL/CTR TK/L&R XFR/CTL & IND	2QL	R26
121VU	FUEL/CTR TK/L&R XFR/CTL & IND	1QL	R25
** ON A/C NOT FOR ALL
123VU	L WING TK/PUMP 1/STBY SPLY	11QA	AD12
123VU	R WING TK/PUMP 1/STBY SPLY	12QA	AE12

Subtask 28-11-00-410-092-A ** ON A/C NOT FOR ALL

B. Close Access
(1) Make sure that the work area is clean and clear of tools and other items.
(2) Install dry bay access-panels 521AZ ( 621AZ) and 521BZ ( 621BZ) (Ref. AMM TASK 57-27-11-400-005).
(3) Install magnetic fuel-level gage 106QM (107QM) which is between the manhole and the dry bay (Ref. AMM TASK 28-43-21-400-001).
(4) Install applicable fuel-tank access panels 540BB ( 640BB) (Ref. AMM TASK 57-27-11-400-001).
(5) Install pressure relief panels 521AB ( 621AB) (Ref. AMM TASK 57-41-37-400-002).

Subtask 28-11-00-860-132-A ** ON A/C NOT FOR ALL

C. Aircraft Maintenance Configuration
(1) Refuel the applicable fuel tanks (Ref. AMM TASK 12-11-28-650-003).
(2) If applicable, retract the flaps fully (Ref. AMM TASK 27-50-00-866-009).

Subtask 28-11-00-942-123-A ** ON A/C NOT FOR ALL

D. Removal of equipment
(1) Make sure that the work area is clean and clear of tools and other items.
(2) Remove the safety barriers.
(3) Remove the warning notices.
(4) Remove the ground support and maintenance equipment, the special and standard tools and all other items.

[Rev.10 from 2021] 2026.04.02 06:17:02 UTC