Removal of the Underwing Panel

TASK 57-51-37-000-010-A
Removal of the Underwing Panel

WARNING: MAKE SURE THAT THE GROUND SAFETY-LOCKS ARE IN POSITION ON THE LANDING GEAR. THIS WILL PREVENT UNWANTED MOVEMENT OF THE LANDING GEAR, AND THUS POSSIBLE INJURY TO PERSONS AND DAMAGE TO THE AIRCRAFT AND/OR EQUIPMENT.

WARNING: MAKE SURE THAT THE FLIGHT CONTROL SAFETY-LOCKS AND THE WARNING NOTICES ARE IN POSITION.

CAUTION: BE CAREFUL WHEN YOU DO MAINTENANCE TASKS ON THE WING TRAILING EDGE:

DO NOT CAUSE DAMAGE TO THE ELECTRICAL CABLE RACEWAYS.
DO NOT CAUSE DAMAGE TO THE ELECTRICAL CABLE INSTALLATIONS.
MAKE SURE THAT THE ELECTRICAL CABLES ARE INSTALLED CORRECTLY. INCORRECT INSTALLATION CAN CAUSE DAMAGE.

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	1	ACCESS PLATFORM 4M (13 FT)
No specific	AR	BAG - PLASTIC
No specific	AR	CAP - BLANKING
No specific	AR	SAFETY BARRIER(S)
No specific	AR	SAFETY CLIP - CIRCUIT BREAKER
No specific	1	WARNING NOTICE(S)

B. Referenced Information

REFERENCE	DESIGNATION
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 28-21-49-000-001-A	Removal of the Fuel Pump Fairings
TASK 33-42-11-000-001-A	Removal of the Landing Light
TASK 57-51-15-000-001-A	Removal of the Shroud Box
Underwing Panel Harnesses - Location and Detail
Underwing Panel

3. Job Set-up
Subtask 57-51-37-860-064-A

A. Aircraft Maintenance Configuration
(1) Make sure that the aircraft electrical circuits are de-energized (Ref. AMM TASK 24-41-00-862-002).

Subtask 57-51-37-941-068-A

B. 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) in the cockpit to tell persons not to operate the flaps or the slats.

Subtask 57-51-37-010-059-A

C. Get Access
(1) Put the ACCESS PLATFORM 4M (13 FT) below the applicable zone 571(671).
(2) Remove the applicable landing light 7LB (8LB) (Ref. AMM TASK 33-42-11-000-001).
(3) Disconnect the shroud box (Ref. AMM TASK 57-51-15-000-001).
(4) Put the ACCESS PLATFORM 3M (10 FT)- ADJUSTABLE in position below the applicable zone 540(640).

Subtask 57-51-37-865-062-A

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

PANEL	DESIGNATION	FIN	LOCATION
** ON A/C ALL
FOR FIN: 25QA (PUMPFUEL NO 2, L WING TK) FOR FIN: 21QA (PUMPFUEL NO 1, L WING TK)
121VU	FUEL/L WING TK/PUMP2 SPLY	7QA	N26
121VU	FUEL/L WING TK/PUMP1 SPLY	1QA	N23
123VU	L WING TK/PUMP 1/STBY SPLY	11QA	AD12
FOR FIN: 26QA (PUMPFUEL NO 2, R WING TK) FOR FIN: 22QA (PUMPFUEL NO 1, R WING TK)
121VU	FUEL/R WING TK/PUMP2 SPLY	8QA	Q26
121VU	FUEL/R WING TK/PUMP1 SPLY	2QA	Q23
123VU	R WING TK/PUMP 1/STBY SPLY	12QA	AE12

4. Procedure
Subtask 57-51-37-020-062-A

A. Removal of the Harnesses from the Underwing Panel

Underwing Panel Harnesses - Location and Detail

Underwing Panel

(1) Remove the fuel pump fairings to get access to the harnesses (7) (Ref. AMM TASK 28-21-49-000-001).
(2) Remove the plug connectors (9) from the connectors on the fuel pump housings.
(3) Remove the backshells (10) from the plug connectors (9) and the harnesses (7).
(4) Remove and discard the cable ties (11).
(5) Loosen the nuts (2) to release the harnesses (7) from the brackets (8).
(6) To remove the clamps (5) and the guides (4) from the brackets (8), remove:

The bolts (6)
The nuts (3).

(7) Carefully pull the harnesses (7) above the underwing panel (21).
(8) Loosely install the plug connectors (9) and the backshells (10).
(9) Put CAP - BLANKING on the disconnected connectors and the plug connectors (9).
(10) Put the harnesses (7) into a BAG - PLASTIC and attach it to the structure.

Subtask 57-51-37-020-059-A

B. Removal of the Underwing Panel

Underwing Panel

(1) Hold the underwing panel (21) until you remove it.
(2) Remove and discard the cotter-pins (35).
(3) Record the position of the bolts (31) and the nuts (34) for the installation procedure.
(4) Remove the nuts (34) and the bolts (31).
(5) Remove the sleeve bushings (33).
(6) Disconnect the rods (28) from the brackets (32).
(7) Remove the nuts (27), the bolts (23) and disconnect the bonding straps (26) from the buttstrap (22).
(8) Remove the nuts (25) and the bolts (24).
(9) Remove the underwing panel (21).

[Rev.10 from 2021] 2026.04.02 06:31:15 UTC