External Temporary Leak Test of the Dry Bay

TASK 28-11-00-790-804-A
External Temporary Leak Test of the Dry Bay

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

NOTE: A permanent repair is to be completed at the next maintenance interval or 600FH.

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	AR	AIR SOURCE 0.3 TO 0.7 BAR (5 TO 10 PSI)- FILTERED, DRY
No specific	1	INDICATOR - GAS COMBUSTIBLE
No specific	AR	SAFETY BARRIER(S)
No specific	AR	WARNING NOTICE(S)
DETDBCPA320TR	1	DRY BAY TEMPORARY REPAIR KIT
RCHSDB320	1	HOT AIR BLOWER

B. Consumable Materials

REFERENCE	DESIGNATION
(Material No.06ABA1)	Polysulfide Sealant-Fuel Tank Brushable -
(Material No.06ABF1)	Polysulfide Sealant-Fuel Tank Quick Curing -

C. Work Zones and Access Panels

ZONE/ACCESS	ZONE DESCRIPTION
521AB, 621AB

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 27-84-00-710-001-A	Operational Test of the Slat System
TASK 27-84-45-000-005-A	Removal of the Torque Shaft
TASK 28-10-00-910-001-A	Safety Procedures When You Do Work in a Fuel Tank
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
Dry Bay - Access ** ON A/C NOT FOR ALL
Dry Bay - Access ** ON A/C NOT FOR ALL

3. Job Set-up
Subtask 28-11-00-941-121-A

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 position in the cockpit to tell persons not to operate the flight controls.
(3) As necessary, use the applicable SAFETY BARRIERS, specified by the operator's instructions and your local regulations.

Subtask 28-11-00-860-133-A

B. Aircraft Maintenance Configuration
(1) Fully extend the flaps and slats (Ref. AMM TASK 27-50-00-866-008).

Subtask 28-11-00-010-094-A

C. Get Access
(1) Put an ACCESS PLATFORM 2M (6 FT) in the position below the applicable access panel.
(2) Remove pressure relief panels 521AB ( 621AB) (Ref. AMM TASK 57-41-37-000-004).
(3) Remove the torque shaft in front of access panel 1 (Ref. AMM TASK 27-84-45-000-005).
(4) Remove the cover of access panel 1.

Subtask 28-11-00-869-081-A

D. Lower Explosive Limit (LEL) Test
(1) Do a test of air in the dry bay section with the INDICATOR - GAS COMBUSTIBLE to measure the fuel gas concentration.
(2) If the fuel gas concentration is less than 3% of the applicable LEL (or less than the Local Regulatory-Authority limit), continue the removal procedure.
(3) If the fuel gas concentration is more than 3% of the LEL:

Blow the clean filtered air from an AIR SOURCE 0.3 TO 0.7 BAR (5 TO 10 PSI)- FILTERED, DRY through the applicable area.

(a) Wait for one hour and then measure the fuel gas concentration in the applicable area again:

If the fuel gas concentration is less than 3% of the LEL (or less than the Local Regulatory-Authority limit), continue the removal procedure.

Subtask 28-11-00-480-075-A

E. Installation of the vision equipment
(1) In the DETDBCPA320TR DRY BAY TEMPORARY REPAIR KIT get the following items:

Tablet with holder (B2)
Safety vacuum cup (B3)
Camera with holder and flashlight (B5)
If necessary, you can use one more suction cup camera-holder (B6).

NOTE: It is necessary to do a check of the batteries of the camera, the flashlight and the tablet are fully charged before the operation. If necessary, you can use the chargers (B1).

NOTE: The autonomy of the vision device is around 2 hours. Two batteries (B4) are available for the flashlight and for the camera. These two batteries (B4) will increase the working time limit to 6 hours. When you see the message on the tablet, it is necessary to change the batteries of the camera and the flashlight in 10 minutes or less.

(2) Install the safety vacuum cup (B3).
(3) Install the tablet with the holder (B2) on the bottom surface of the wing adjacent to access panel 1 hole of the dry bay.
(4) Connect the safety cable of the tablet (B2) to the safety vacuum cup (B3).
(5) Turn on the tablet (B2), the camera (B5) and the flashlight (B5).
(6) Connect (wireless connection) the camera (B5) to the tablet (B2) and make sure that the video link operates correctly.
(7) The video is to see the inner side of the dry bay. You can use the zoom function for a better view.

NOTE: It is also possible to save the pictures and the videos while you work in the area.

(8) Set the camera with the holder and the flashlight (B5) on the rib in the dry bay.

4. Procedure
Subtask 28-11-00-210-064-A

A. Visual inspection

Dry Bay - Access ** ON A/C NOT FOR ALL

(1) Do a visual inspection in the dry bay to find the location of the leak.
(2) For a clear inspection:
(a) Clean the kerosene in the dry bay. If necessary, use the extension stick (A1) with the cleaning head (A6).

NOTE: If necessary, you can use the extension stick holder (A4).

(b) To dry the leak area, connect an AIR SOURCE 0.3 TO 0.7 BAR (5 TO 10 PSI)- FILTERED, DRY to:

The compressed air gun (A8)
The extension stick (A1).

If there is no leakage, the talcum powder will become white
If there is leakage, the talcum powder stays dark.

(e) Find the exit point of the leak.

Subtask 28-11-00-360-051-A

B. Sealant application

Dry Bay - Access ** ON A/C NOT FOR ALL

(1) Move the fuel to the other wing tank or defuel the wing tank to let the sealant bond correctly.
(2) Clean the kerosene in the dry bay with the extension stick (A1) and the cleaning head (A6).

NOTE: If necessary, you can use the extension stick holder (A4).

(3) If necessary, remove the incorrect sealant with the extension stick (A1) and the scraping head (A3).
(4) To dry the leak area, connect the AIR SOURCE 0.3 TO 0.7 BAR (5 TO 10 PSI)- FILTERED, DRY to:

The compressed air gun (A8)
The extension stick (A1).

(5) Solvent clean and remove the grease with the cleaning head (A6) on the extension stick (A1).
(6) Apply the sealant lightly in the leak area with the abrading head (A5) on the extension stick (A1).
(7) Use the vacuum cleaning (A9) to remove the sealant waste in the dry bay.
(8) Solvent clean and remove the grease with the cleaning head (A6) on the extension stick (A1).
(9) Apply Polysulfide Sealant-Fuel Tank Brushable - (Material No.06ABA1) or Polysulfide Sealant-Fuel Tank Quick Curing - (Material No.06ABF1) on the leak area with the extension stick (A1), the extrusion gun (A10) and the semkit nozzle (A11).
(10) Make the sealant smooth with the extension stick (A1) and the scraping head (A3).
(11) If the sealant cure time is not sufficient before the aircraft takeoff, use the RCHSDB320 HOT AIR BLOWER.
(12) Do the procedure that follows to decrease the polymerization time as follows:
(a) Install the RCHSDB320 HOT AIR BLOWER on the dry bay as follows:
1 Connect the compressed air supply to the control panel.

NOTE: Pressure: 0.5 bar (7 psi) to 0.7 bar (10 psi). Flow: 500 l.min (130 USgal.mn) to 700 l.min (180 USgal.mn).

2 Connect the power supply and set the control panel switch to the ON position.
3 Install the RCHSDB320 HOT AIR BLOWER interface in access panel 1 hole.
(b) Operate the RCHSDB320 HOT AIR BLOWER, select the cycle time, the temperature and start the curing cycle.

NOTE: The curing time changes in relation to the type of sealant. It is necessary to calculate the applicable time (refer to the safety datasheet of the sealant).

(c) At the end of the cycle, remove the RCHSDB320 HOT AIR BLOWER from the aircraft as follows:
1 Disconnect the RCHSDB320 HOT AIR BLOWER interface from access panel 1 hole.
2 De-energize the RCHSDB320 HOT AIR BLOWER.
3 Disconnect the power supply from the control unit.
4 Disconnect the compressed air from the control panel.

5. Close-up
Subtask 28-11-00-410-093-A

A. Close Access
(1) Make sure that the work area is clean and clear of tools and other items.
(2) Install access panel 1.
(3) Install the torque shaft in the front of access panel 1 and do the test procedure (Ref. AMM TASK 27-84-00-710-001).
(4) Install the wing leading-edge access-panels (Ref. AMM TASK 57-41-37-400-002).

Subtask 28-11-00-860-134-A

B. Aircraft Maintenance Configuration
(1) If necessary, transfer the fuel back to the applicable wing tank.
(2) If the tank is defueled, refuel the applicable wing tanks (Ref. AMM TASK 12-11-28-650-003).
(3) If applicable, retract the flaps and the slats (Ref. AMM TASK 27-50-00-866-009).

Subtask 28-11-00-942-124-A

C. 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 07:21:40 UTC