Access to the Fuel Tanks and the Work Areas

TASK 28-10-00-910-002-A
Access to the Fuel Tanks and the Work Areas

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.

CAUTION: DO NOT USE THE FUEL PIPES AND THE EQUIPMENT AS HANDHOLDS WHEN YOU DO WORK IN A FUEL TANK. THIS WILL PREVENT DAMAGE TO THEM.

1. Reason for the Job
Self explanatory
2. Job Set-up Information
A. Fixtures, Tools, Test and Support Equipment

REFERENCE	QTY	DESIGNATION
No specific	1	ACCESS PLATFORM 3M (10 FT)- ADJUSTABLE
No specific	AR	ACCESS PLATFORM 5M (16 FT)- ADJUSTABLE
No specific	1	AIR SOURCE 0.3 TO 0.7 BAR (5 TO 10 PSI)- FILTERED, DRY
No specific	AR	CLOTH - PROTECTIVE
No specific	1	CONTAINER-NON METALLIC
No specific	1	INDICATOR - GAS COMBUSTIBLE
No specific	AR	LIGHT SOURCE - SPARK-PROOF
No specific	AR	MAT - PROTECTIVE
No specific	AR	RESPIRATOR - AIR SUPPLIED
No specific	AR	SAFETY BARRIER(S)
No specific	AR	WARNING NOTICE(S)
98D57004013000	1	HOOK-COVER (RIB 2 SURGE DOORS)
98D57004014000	1	HOOK-COVER (RIB2-SURGE DOORS)
PA1V1	1	PURGE AIR KIT

B. Consumable Materials

REFERENCE	DESIGNATION
(Material No.14QEB1)	Wire-Locking Dia: 0.6 mm CRES Nickel Alloy -
(Material No.14SBA1)	Textile-Lint free Cotton -

C. Work Zones and Access Panels

ZONE/ACCESS	ZONE DESCRIPTION
540AZ, 540BZ, 640AZ, 640BZ

D. Referenced Information

REFERENCE	DESIGNATION
TASK 12-34-24-869-002-A	Aircraft Grounding (Earthing) for the Maintenance Operations
TASK 12-34-24-869-002-A-01	Aircraft Grounding (Earthing) during Transit, Turnaround or Overnight Stop
TASK 24-38-51-000-001-A	Removal of the Battery
TASK 24-38-51-400-001-A	Installation of the Battery
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 28-00-00-200-001-A-01	Inspection of the Fuel Tank Bonding
TASK 28-00-00-200-001-A	Inspection of the Fuel Tank Bonding
TASK 28-00-00-200-001-A-01	Inspection of the Fuel Tank Bonding
TASK 28-11-37-000-001-A	Removal of the Inner Manhole-Cover ACT
TASK 28-11-37-400-001-A	Installation of the Inner Manhole-Cover ACT
TASK 28-12-45-000-001-A	Removal of the Panel Assembly
TASK 28-12-45-400-002-A	Installation of the Panel Assembly
TASK 28-12-46-000-001-A	Removal of the Overpressure Protector Outlet
TASK 28-12-46-400-001-A	Installation of the Overpressure Protector Outlet
TASK 28-12-47-000-001-A	Removal of the NACA Vent Intake
TASK 28-12-47-400-001-A	Installation of the NACA Vent Intake
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 28-25-00-869-001-A	Fuel Transfer
TASK 28-42-15-000-001-A	Removal of the Wing Tank Fuel-Quantity-Probes
TASK 28-42-15-000-001-B	Removal of the Wing-Tank Fuel-Quantity Probes
TASK 28-42-15-000-002-A	Removal of the Center Tank Fuel-Quantity-Probe
TASK 28-42-15-000-004-A	Removal of the Center (Transfer) Tank Fuel-Quantity Probes
TASK 28-42-15-000-005-A	Removal of the Wing-Tank Fuel-Quantity Probes
TASK 28-42-15-400-001-A	Installation of the Wing Tank Fuel-Quantity-Probes
TASK 28-42-15-400-001-B	Installation of the Wing-Tank Fuel-Quantity Probes
TASK 28-42-15-400-002-A	Installation of the Center Tank Fuel-Quantity-Probe
TASK 28-42-15-400-004-A	Installation of the Center (Transfer) Tank Fuel-Quantity Probe
TASK 28-42-15-400-005-A	Installation of the Wing-Tank Fuel-Quantity Probes
TASK 57-17-11-000-001-A	Removal of Access Cover 147AZ(148AZ)
TASK 57-17-11-000-001-B	Removal of Access Cover 148AZ or/and the ACT-Equipment Support Door
TASK 57-17-11-400-001-A	Installation of Access Cover 147AZ(148AZ)
TASK 57-17-11-400-001-B	Installation of Access Cover 148AZ or/and the ACT-Equipment Support-Door
TASK 57-27-11-000-001-A	Removal of the Access Panel
TASK 57-27-11-000-002-A	Removal of the Access Panel
TASK 57-27-11-400-001-A	Installation of the Access Panel
TASK 57-27-11-400-002-A	Installation of the Access Panel
TASK 57-27-12-000-002-A	Removal of the Rib 2 Access Panel 540AZ(640AZ) or 540BZ(640BZ)
TASK 57-27-12-400-002-A	Installation of the Rib 2 Access Panel 540AZ (640AZ) or 540BZ (640BZ)
Safety Areas And Precautions

3. Job Set-up
Subtask 28-10-00-941-053-A

A. Safety Precautions
(1) As necessary, use the applicable SAFETY BARRIERS, specified by the operator's instructions and your local regulations.
(2) Put the WARNING NOTICE(S) around the aircraft to show that the fuel tanks are open.

Subtask 28-10-00-860-050-A

B. Aircraft Maintenance Configuration
(1) Drain the fuel from the applicable fuel tank as follows:

Do the pressure defuel (Ref. AMM TASK 28-25-00-650-001) or
Do the fuel transfer (Ref. AMM TASK 28-25-00-869-001).

(2) Drain the remaining fuel from the applicable fuel tank(s) (Ref. AMM TASK 28-25-00-650-003).
(3) De-energize the aircraft electrical circuits
(Ref. AMM TASK 24-41-00-862-002).
(4) Make sure that the aircraft is electrically grounded (Ref. AMM TASK 12-34-24-869-002).
(5) Make sure that all the access platforms and the associated equipment are electrically bonded.
(6) Disconnect the electrical ground power unit.

WARNING: DISCONNECT THE AIRCRAFT BATTERIES BEFORE YOU GET ACCESS TO THE FUEL TANKS AND THE WORK AREAS. THIS IS TO PREVENT THE RISK OF FIRE AND/OR EXPLOSION IN THE FUEL TANKS. IF YOU DO NOT OBEY THIS INSTRUCTION, INJURY TO PERSONS AND/OR DAMAGE TO EQUIPMENT CAN OCCUR.

(7) Disconnect the aircraft batteries to isolate the aircraft electrical power but do not remove them (Ref. AMM TASK 24-38-51-000-001).

Subtask 28-10-00-010-052-A ** ON A/C NOT FOR ALL

C. Get Access
(1) Put the ACCESS PLATFORM 5M (16 FT)- ADJUSTABLE in position.
(2) Remove the applicable access panel (Ref. AMM TASK 57-27-11-000-001), (Ref. AMM TASK 57-27-11-000-002), (Ref. AMM TASK 57-17-11-000-001), (Ref. AMM TASK 28-12-45-000-001), (Ref. AMM TASK 28-12-46-000-001) or (Ref. AMM TASK 28-12-47-000-001).

Subtask 28-10-00-010-052-C ** ON A/C NOT FOR ALL

Subtask 28-10-00-869-051-A

D. Preparation of the Tank (Method 1)

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 10% 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 28-10-00-869-053-A

E. Preparation of the Tank (Method 2)
(1) Use the PA1V1 PURGE AIR KIT and refer to the manufacturer's instructions to operate it.

NOTE: You can also use PRG224 (MODULAR PURGE AIR SYSTEM) as an alternative to the PA1V1 PURGE AIR KIT.

Subtask 28-10-00-750-051-A

F. Test
(1) Do a test on the air in the tank with the INDICATOR - GAS COMBUSTIBLE after six hours. If the fuel-gas concentration is more than 10% of the Lower Explosion Limit (LEL), continue to blow air through the tank. Measure the fuel-gas concentration every 15 minutes (in four different areas of the fuel tank) until the fuel-gas concentration is less than 10% of the LEL (or less then the Local Regulatory-Authority limit).

Subtask 28-10-00-010-053-A ** ON A/C NOT FOR ALL

G. To Get Access to the Inboard of RIB2
(1) For the left wing:

open the surge doors 540AZ and/or 540BZ and install the 98D57004013000 HOOK-COVER (RIB 2 SURGE DOORS) and or the 98D57004014000 HOOK-COVER (RIB2-SURGE DOORS).

(2) For the right wing:

open the surge doors 640AZ and/or 640BZ and install the 98D57004013000 HOOK-COVER (RIB 2 SURGE DOORS) and or the 98D57004014000 HOOK-COVER (RIB2-SURGE DOORS).

Subtask 28-10-00-010-053-B ** ON A/C NOT FOR ALL

G. To Get Access to the Inboard of RIB2
(1) Put the ACCESS PLATFORM 3M (10 FT)- ADJUSTABLE in position below the applicable zone 540 (640).
(2) Remove the applicable RIB2 access panels that follow:
(a) For the left wing, remove 540AZ and 540BZ (Ref. AMM TASK 57-27-12-000-002).
(b) For the right wing, remove 640AZ and 640BZ (Ref. AMM TASK 57-27-12-000-002).

Subtask 28-10-00-941-054-A

H. Preparation of Person(s) and Equipment to go into the Fuel Tank

WARNING: DO NOT GO INTO A FUEL TANK UNTIL THE FUEL-GAS CONCENTRATION IS LESS THAN 10% OF THE APPLICABLE LEL (LOWER EXPLOSIVE LIMIT) (OR LESS THAN THE LOCAL REGULATORY-AUTHORITY LIMIT).

WARNING: DO NOT REMOVE YOUR RESPIRATOR WHILE YOU ARE IN A FUEL TANK (UNLESS THE FUEL-GAS CONCENTRATION IS LESS THAN 5% OF LEL (LOWER EXPLOSIVE LIMIT)). YOU WILL BECOME ILL OR DIE.

WARNING: USE THE APPROVED PROTECTIVE CLOTHING WHEN YOU GO IN A FUEL TANK.

(1) Make sure that each person has two RESPIRATOR - AIR SUPPLIED.
(2) Make sure that the respirators operate satisfactorily before use.
(3) Put on CLOTH - PROTECTIVE.
(4) Remove all the loose objects from pockets of overalls and remove all your personal jewelry.
(5) Make a check list of all the tools and equipment you put into the fuel tank.
(6) Make sure that the person in the fuel tank and the safety person agree to the safety signals between them.
(7) Touch a known ground point to release the static electricity from your body, before you go into the fuel tank.
(8) Remove the remaining fuel with a Textile-Lint free Cotton - (Material No.14SBA1) .
(9) Put MAT - PROTECTIVE on the bottom of the fuel tank in the work area.
(10) Put all the tools and equipment in a CONTAINER-NON METALLIC and of smaller dimensions than the internal tank openings.

WARNING: USE PROTECTIVE GOGGLES AND GLOVES WHEN YOU REMOVE OR INSTALL LOCKWIRE. EACH TIME YOU CUT LOCKWIRE, REMOVE AND DISCARD IT IMMEDIATELY. LOOSE LOCKWIRE CAN CUT YOU OR MAKE YOU BLIND, AND/OR CAN CAUSE DAMAGE.

(11) When possible, safety all the applicable components with 14QEB1Wire-Locking Dia: 0.6 mm CRES Nickel Alloy - before you put them into the fuel tank.

4. Procedure
Subtask 28-10-00-610-052-A

A. Safety of Person(s) in the Tank
(1) Continue to blow clean, filtered air through the tank while persons are in the tank. Continuously monitor the air in the tank (with the combustible gas indicator) to make sure the fuel gas concentration stays at a safe level.
(2) Use only approved LIGHT SOURCE - SPARK-PROOFS and tools when you are in the fuel tank.
(3) Use only approved solvents and cleaning agents.

5. Close-up
Subtask 28-10-00-410-053-A ** ON A/C NOT FOR ALL

A. Close Access
(1) If removed, install the structure and/or equipment.
(2) Make sure that the bonding straps are in position and connected correctly:
(a) Make sure that they are not damaged or broken and show no sign of corrosion (Ref. AMM TASK 28-00-00-200-001).
(3) Do an inspection of the FQI probes in the compartment. Make sure that they are:

Correctly installed
Not corroded
Not damaged
Have the correct clearance from the structure (Ref. AMM TASK 28-42-15-400-001) or (Ref. AMM TASK 28-42-15-400-002).

NOTE: If necessary, replace an applicable FQI probe, refer:

For the wing tank, refer to (Ref. AMM TASK 28-42-15-000-001) and (Ref. AMM TASK 28-42-15-400-001)

For the center tank, refer to (Ref. AMM TASK 28-42-15-000-002) and (Ref. AMM TASK 28-42-15-400-002).

(4) If applicable, remove the 98D57004013000 HOOK-COVER (RIB 2 SURGE DOORS) and/or the 98D57004014000 HOOK-COVER (RIB2-SURGE DOORS) from the surge door(s):
(a) Carefully close the surge door(s).
(5) Make sure that you remove all the tools, equipment and cleaning materials on the check list from the tank(s).
(6) Install the removed access panels (Ref. AMM TASK 57-27-11-400-001), (Ref. AMM TASK 57-27-11-400-002), (Ref. AMM TASK 57-17-11-400-001), (Ref. AMM TASK 28-12-45-400-002), (Ref. AMM TASK 28-12-46-400-001) or (Ref. AMM TASK 28-12-47-400-001).

Subtask 28-10-00-410-053-B ** ON A/C NOT FOR ALL

Correctly installed
Not corroded
Not damaged
Have the correct clearance from the structure (Ref. AMM TASK 28-42-15-400-004) or (Ref. AMM TASK 28-42-15-400-005).

NOTE: If necessary, replace an applicable FQI probe:

For the center tank, refer to (Ref. AMM TASK 28-42-15-000-004) and (Ref. AMM TASK 28-42-15-400-004)

For the wing tank, refer to (Ref. AMM TASK 28-42-15-000-005) and (Ref. AMM TASK 28-42-15-400-005).

Subtask 28-10-00-410-053-C ** ON A/C NOT FOR ALL

Correctly installed
Not corroded
Not damaged
Have the correct clearance from the structure (Ref. AMM TASK 28-42-15-400-004) or (Ref. AMM TASK 28-42-15-400-005).

NOTE: If necessary, replace an applicable FQI probe:

For the center tank, refer to (Ref. AMM TASK 28-42-15-000-004) and (Ref. AMM TASK 28-42-15-400-004)

For the wing tank, refer to (Ref. AMM TASK 28-42-15-000-005) and (Ref. AMM TASK 28-42-15-400-005).

Subtask 28-10-00-410-053-E ** ON A/C NOT FOR ALL

A. Close Access
(1) Make sure that you remove all the tools, the equipments and the cleaning materials (that are on the check list) from the tank(s).
(2) If removed, install the structure and/or equipment.
(3) Make sure that the bonding straps are in position and connected correctly:
(a) Make sure that they are not damaged or broken and do not show signs of corrosion (Ref. AMM TASK 28-00-00-200-001).
(4) Do an inspection of the FQI probes in the compartment. Make sure that they are:

Correctly installed
Not corroded
Not damaged
Have the correct clearance from the structure (Ref. AMM TASK 28-42-15-400-001) or (Ref. AMM D/O 28-42-15-40).

(5) If necessary, replace the applicable FQI probe, refer:
(a) For the wing tank, refer to (Ref. AMM TASK 28-42-15-000-001) and (Ref. AMM TASK 28-42-15-400-001).
(b) For the center tank, refer to (Ref. AMM TASK 28-42-15-000-002).
(6) Install the applicable RIB2 access panels that follow:
(a) For the left wing, install 540AZ and 540BZ (Ref. AMM TASK 57-27-12-400-002).
(b) For the right wing, install 640AZ and 640BZ (Ref. AMM TASK 57-27-12-400-002).
(7) Install the removed access panels (Ref. AMM TASK 57-27-11-400-001), (Ref. AMM TASK 57-27-11-400-002), (Ref. AMM TASK 57-17-11-400-001), (Ref. AMM TASK 28-12-45-400-002), (Ref. AMM TASK 28-12-46-400-001) or (Ref. AMM TASK 28-12-47-400-001).

Subtask 28-10-00-410-053-F ** ON A/C NOT FOR ALL

Correctly installed
Not corroded
Not damaged
Have the correct clearance from the structure (Ref. AMM TASK 28-42-15-400-004) or (Ref. AMM TASK 28-42-15-400-005).

(5) If necessary, replace the applicable FQI probe:
(a) For the center tank, refer to (Ref. AMM TASK 28-42-15-000-004) and (Ref. AMM TASK 28-42-15-400-004).
(b) For the wing tank, refer to (Ref. AMM TASK 28-42-15-000-005) and (Ref. AMM TASK 28-42-15-400-005).
(6) Install the applicable RIB2 access panels that follow:
(a) For the left wing, install 540AZ and 540BZ (Ref. AMM TASK 57-27-12-400-002).
(b) For the right wing, install 640AZ and 640BZ (Ref. AMM TASK 57-27-12-400-002).
(7) Install the removed access panels (Ref. AMM TASK 57-27-11-400-001), (Ref. AMM TASK 57-27-11-400-002), (Ref. AMM TASK 57-17-11-400-001), (Ref. AMM TASK 28-12-45-400-002), (Ref. AMM TASK 28-12-46-400-001) or (Ref. AMM TASK 28-12-47-400-001).

Subtask 28-10-00-860-051-A

B. Aircraft Maintenance Configuration
(1) Connect the aircraft batteries (Ref. AMM TASK 24-38-51-400-001).

Subtask 28-10-00-942-052-A

C. 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 access platform(s).
(4) Remove the WARNING NOTICE(S).
(5) Remove the ground support and maintenance equipment, the special and standard tools and all other items.

[Rev.10 from 2021] 2026.04.01 03:59:40 UTC