Removal of the Aft Cargo-Trim Air-Valve

TASK 21-43-51-000-001-A
Removal of the Aft Cargo-Trim Air-Valve

WARNING: MAKE SURE THAT AIR IS NOT SUPPLIED TO THE AIR CONDITIONING SYSTEM FROM THE MAIN ENGINE, THE APU OR A GROUND SOURCE. HOT COMPRESSED AIR CAN CAUSE INJURY TO PERSONNEL.

FIN: 12HC ** 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)
No specific	AR	CAP - BLANKING
No specific	AR	PLUG - BLANKING
No specific	AR	SAFETY CLIP - CIRCUIT BREAKER

B. Work Zones and Access Panels

ZONE/ACCESS	ZONE DESCRIPTION
197BB
197KB

C. Referenced Information

REFERENCE	DESIGNATION
TASK 24-41-00-861-002-A	Energize the Aircraft Electrical Circuits from the External Power
TASK 24-41-00-861-002-A-01	Energize the Aircraft Electrical Circuits from the APU
TASK 24-41-00-861-002-A-02	Energize the Aircraft Electrical Circuits from Engine 1(2)
TASK 53-35-13-000-002-A	Removal of the Quick-Release Access Panels from the Belly Fairing Structure
Aft Cargo-Trim Air-Valve ** ON A/C NOT FOR ALL
Aft Cargo-Trim Air-Valve ** ON A/C NOT FOR ALL

3. Job Set-up
Subtask 21-43-51-861-050-A ** ON A/C NOT FOR ALL

A. Energize the aircraft electrical circuits (Ref. AMM TASK 24-41-00-861-002).

Subtask 21-43-51-865-061-A ** ON A/C NOT FOR ALL

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

PANEL	DESIGNATION	FIN	LOCATION
** ON A/C NOT FOR ALL
49VU	AIR COND/AFT CARGO/VENT/CTL & MONG	31HN	C07
** ON A/C NOT FOR ALL
49VU	AIR COND/AFT CARGO/VENT & HTG/CTL & MONG	31HN	C07
** ON A/C NOT FOR ALL
122VU	AIR COND/AFT CARGO VENT/FAN	30HN	S22

Subtask 21-43-51-941-050-C ** ON A/C NOT FOR ALL

C. Safety Precautions
(1) On the panel 30VU:
(a) Make sure that:

the APU BLEED pushbutton switch is in the off position (the ON legend is off) and,
the ENG 1 BLEED and the ENG 2 BLEED pushbutton switches are in the off position (the OFF legends are on).

(b) Put a warning notice in position to tell persons not to operate these pushbutton switches.
(2) On the HP ground connector put a warning notice in position to tell persons not to supply the ground air.

Subtask 21-43-51-010-050-A ** ON A/C NOT FOR ALL

D. Get Access
(1) Put the ACCESS PLATFORM 2M (6 FT) in position at the access panel 197BB.
(2) Remove the access panel 197BB (Ref. AMM TASK 53-35-13-000-002).

Subtask 21-43-51-010-050-C ** ON A/C NOT FOR ALL

D. Get Access
(1) Put the ACCESS PLATFORM 2M (6 FT) in position at the access panel 197KB.
(2) Remove the access panel 197KB (Ref. AMM TASK 53-35-13-000-002).

4. Procedure
Subtask 21-43-51-020-050-B ** ON A/C NOT FOR ALL

A. Removal of the Trim Air Valve
(1) Disconnect the electrical connector (6).
(2) Put the CAP-BLANKING on each disconnected electrical connector and receptacle.
(3) Remove the nut (4), the washers (5), the screw (7) and disconnect the bonding strap (8).
(4) Remove the lock pin (13) from the stowage hole (12).
(5) Turn the manual override lever (10) to the closed position and install the lock pin (13) in the hole (11).
(6) Remove the clamps (3), the trim air valve (9) and the O-rings (2).
(7) Put the PLUG-BLANKING in each disconnected line end.

[Rev.10 from 2021] 2026.03.31 23:05:44 UTC