Reactivation of the FWD Cargo Compartment-Heating Trim-Air Valve

TASK 21-43-00-440-001-A
Reactivation of the FWD Cargo Compartment-Heating 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.

ZONE: 130
FIN: 2HC ** ON A/C NOT FOR ALL

1. Reason for the Job
MMEL 21-43-01A
FWD CARGO COMPARTMENT HEATING
2. Job Set-up Information
A. Fixtures, Tools, Test and Support Equipment

REFERENCE	QTY	DESIGNATION
No specific	1	ACCESS PLATFORM 2M (6 FT)

B. Work Zones and Access Panels

ZONE/ACCESS	ZONE DESCRIPTION
130	FWD CARGO COMPT AFT BULKHEAD OF AVNCS COMPT TO FWD PRESSURE BULKHEAD OF WING CENTER BOX
131NW, 131PW, 825

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 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 25-54-12-000-001-A	Removal of the Forward Cargo-Compartment Partition
TASK 25-54-12-400-001-A	Installation of the Forward Cargo-Compartment Partition
TASK 52-30-00-860-001-A	Open the FWD or Aft Cargo-Compartment Door with the Yellow Electric Pump
TASK 52-30-00-860-002-A	Close the FWD or Aft Cargo-Compartment Door with the Yellow Electric Pump
FWD CC Trim-Air Valve

3. Job Set-up
Subtask 21-43-00-861-053-A ** ON A/C NOT FOR ALL

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

Subtask 21-43-00-865-054-A ** ON A/C NOT FOR ALL

B. Make sure that this(these) circuit breaker(s) is(are) open, safetied and tagged:

PANEL	DESIGNATION	FIN	LOCATION
** ON A/C NOT FOR ALL
49VU	AIR COND/FWD CARGO/VENT/CTL & MONG	2HN	C08

Subtask 21-43-00-941-057-A ** 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).released.

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

Subtask 21-43-00-010-057-A ** ON A/C NOT FOR ALL

D. Get Access
(1) Open the FWD cargo-compartment door 825 (Ref. AMM TASK 52-30-00-860-001).
(2) Put the ACCESS PLATFORM 2M (6 FT) in position at the FWD cargo-compartment door 825.
(3) Remove the access panels 131NW and 131PW (Ref. AMM TASK 25-54-12-000-001).

4. Procedure
Subtask 21-43-00-440-050-B ** ON A/C NOT FOR ALL

A. Reactivation of the FWD Cargo Compartment-Heating Trim-Air Valve

FWD CC Trim-Air Valve ** ON A/C NOT FOR ALL

WARNING: DO NOT TOUCH THE COMPONENT UNTIL IT IS SUFFICIENTLY COOL TO PREVENT BURNS.

(1) Remove the quick-release pin (4) from the locking hole (3).
(2) Install the quick-release pin to the stowage hole in the body of the trim-air valve (5).
(3) Turn the manual lever (2) to the open position.
(4) Make sure that the manual lever is free to move.
(5) Remove the temporary attachment and the blanking caps from the electrical connectors.

CAUTION: TO PREVENT POSSIBLE CROSS-CONNECTION OF THE ELECTRICAL CONNECTORS, MAKE SURE THAT PLUGS AND RECEPTACLES ARE CLEARLY IDENTIFIED.

(6) Connect the electrical connector (1) to the trim-air valve (5).

NOTE: Make sure that the electrical connector 14HK-A is connected to the valve 14HK.

Subtask 21-43-00-865-069-A ** ON A/C NOT FOR ALL

B. Remove the safety clip(s) and the tag(s) and close this(these) circuit breaker(s):

PANEL	DESIGNATION	FIN	LOCATION
** ON A/C NOT FOR ALL
49VU	AIR COND/FWD CARGO/VENT/CTL & MONG	2HN	C08

5. Close-up
Subtask 21-43-00-410-056-A ** ON A/C NOT FOR ALL

A. Close Access
(1) Make sure that the work area is clean and clear of tools and other items.
(2) Install the access panels 131NW and 131PW (Ref. AMM TASK 25-54-12-400-001).
(3) Remove the access platform(s).
(4) Close the FWD cargo-compartment door 825 (Ref. AMM TASK 52-30-00-860-002).
(5) Remove the WARNING NOTICE(S).

Subtask 21-43-00-862-060-A ** ON A/C NOT FOR ALL

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

[Rev.10 from 2021] 2026.04.02 06:11:18 UTC