Removal of the IGGS In-Tank Housing

TASK 47-20-41-000-001-A
Removal of the IGGS In-Tank Housing

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: YOU MUST WEAR SAFETY BREATHING EQUIPMENT WHEN YOU DO WORK IN THIS AREA. THIS AREA CAN CONTAIN AIR FROM THE TANK INERTING SYSTEM. AIR FROM THIS SYSTEM HAS A LOW-OXYGEN CONTENT AND CAN CAUSE INJURY AND DEATH.

ZONE: 141
FIN: 3YM ** ON A/C NOT FOR ALL

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 2M (6 FT) - ADJUSTABLE
No specific	AR	PLUG - BLANKING
No specific	AR	SAFETY BARRIER(S)
No specific	AR	SAFETY CLIP - CIRCUIT BREAKER

B. Work Zones and Access Panels

ZONE/ACCESS	ZONE DESCRIPTION
141	WING CENTER BOX

C. 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 28-10-00-910-002-A	Access to the Fuel Tanks and the Work Areas
TASK 28-10-00-910-003-A	Safety Procedures When You Do Work in a Dry Fuel Tank
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 47-20-43-000-001-A	Removal of the Dual-Flapper Check Valve
IGGS In-Tank Housing - Location and Detail

3. Job Set-up
Subtask 47-20-41-941-050-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 28-10-00-910-003).
(2) Put the SAFETY BARRIER(S) in position.

Subtask 47-20-41-860-050-A ** ON A/C NOT FOR ALL

B. Aircraft Maintenance Configuration
(1) De-energize the aircraft electrical circuits
(Ref. AMM TASK 24-41-00-862-002).

Subtask 47-20-41-865-050-A ** ON A/C NOT FOR ALL

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

PANEL	DESIGNATION	FIN	LOCATION
** ON A/C NOT FOR ALL
121VU	IGGS/CTRL	7YA	N28
** ON A/C NOT FOR ALL
121VU	IGGS/CTRL	7YA	P28
** ON A/C NOT FOR ALL
122VU	CSAS / CTRL	1HW	U17

Subtask 47-20-41-650-050-A ** ON A/C NOT FOR ALL

D. Fuel Configuration
(1) Defuel the center tank (Ref. AMM TASK 28-25-00-650-001).
(2) Drain the remaining fuel from the center tank (Ref. AMM TASK 28-25-00-650-003).

Subtask 47-20-41-010-050-A ** ON A/C NOT FOR ALL

E. Get Access
(1) Put an ACCESS PLATFORM 2M (6 FT) - ADJUSTABLE at zone 142.
(2) Get access to the center tank (Ref. AMM TASK 28-10-00-910-002).

4. Procedure
Subtask 47-20-41-020-050-A ** ON A/C NOT FOR ALL

CAUTION: BE CAREFUL WHEN YOU TOUCH THIS ASSEMBLY. IT HAS PRECISION- TOLERANCE COMPONENTS WITH VERY POLISHED SURFACES. IF YOU ARE NOT CAREFUL, IT IS VERY EASY TO CAUSE DAMAGE TO THESE COMPONENTS (INTERNAL CONTAMINATION, EXTERNAL IMPACT DAMAGE).

A. Removal of the IGGS In-Tank Housing

NOTE: Two persons are necessary to do this procedure. One in the center tank to hold the IGGS in-tank housing and one on top of the center tank to remove the attaching parts.

(1) Remove the dual-flapper check valve (Ref. AMM TASK 47-20-43-000-001).
(2) Remove the screw (4) and disconnect the bonding lead (5) from the IGGS in-tank housing (3).
(3) Remove the screw (8) and the bonding lead (7).
(4) Disconnect the union (6) from the IGGS in-tank housing (3).
(5) Put the PLUG-BLANKING in each disconnected line end.
(6) Hold the IGGS in-tank housing (3) and remove the nuts (1).
(7) Carefully remove the IGGS in-tank housing (3).
(8) Remove and discard the O-ring (2).

[Rev.10 from 2021] 2026.04.02 06:26:18 UTC