Removal of the Pipe Assembly between the Anti-Ice Valve (if installed) and the Bypass Air Duct of the Primary Heat Exchanger

TASK 21-52-23-000-003-A
Removal of the Pipe Assembly between the Anti-Ice Valve (if installed) and the Bypass Air Duct of the Primary Heat Exchanger

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.

NOTE: The procedure for the removal of the pipe assembly is the same for the left and right side.

FIN: 10HM4 ** ON A/C NOT FOR ALL
FIN: 11HM4 ** 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	AR	PLUG - BLANKING
No specific	AR	SAFETY CLIP - CIRCUIT BREAKER
No specific	AR	WARNING NOTICE(S)

B. Work Zones and Access Panels

ZONE/ACCESS	ZONE DESCRIPTION
FOR [10HM] (PACK 1-AIR CONDITIONING)
191KB
FOR [11HM] (PACK 2-AIR CONDITIONING)
192KB

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
Pipe Assembly ** ON A/C NOT FOR ALL
Pipe Assembly ** ON A/C NOT FOR ALL

3. Job Set-up
Subtask 21-52-23-861-054-A ** ON A/C NOT FOR ALL

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

Subtask 21-52-23-865-063-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
FOR FIN: 10HM (PACK 1AIR CONDITIONING)
122VU	AIR COND/PACK TEMP/CTL SYS1/1/115VAC	1HH	X22
122VU	AIR COND/PACK TEMP/CTL SYS1/1/28VDC	3HH	X21
122VU	AIR COND/PACK TEMP CTL SYS2/1/28VDC	4HH	Y19
122VU	AIR COND/PACK TEMP CTL SYS2/1/115VAC	2HH	Y18
FOR FIN: 11HM (PACK 2AIR CONDITIONING)
122VU	AIR COND/PACK TEMP/CTL SYS1/2/115VAC	21HH	W22
122VU	AIR COND/PACK TEMP/CTL SYS1/2/28VDC	23HH	W21
122VU	AIR COND/PACK TEMP CTL SYS2/2/28VDC	24HH	Y21
122VU	AIR COND/PACK TEMP CTL SYS2/2/115VAC	22HH	Y20

Subtask 21-52-23-010-054-A ** ON A/C NOT FOR ALL

C. Get Access
(1) Remove the access panel (Ref. AMM TASK 53-35-13-000-002).
(a) FOR [10HM] (PACK 1-AIR CONDITIONING)

191KB.

(b) FOR [11HM] (PACK 2-AIR CONDITIONING)

192KB.

Subtask 21-52-23-941-052-A ** ON A/C NOT FOR ALL

D. Safety Precautions
(1) On the overhead panel, on AIR COND panel 30VU:
(a) Make sure that:

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

(b) Put the WARNING NOTICE(S) in position to tell persons not to operate these pushbutton switches.
(2) On the HP ground connector, put the WARNING NOTICE(S) in position to tell persons not to supply the ground air.

4. Procedure
Subtask 21-52-23-020-054-A ** ON A/C NOT FOR ALL

A. Removal of the Pipe Assembly
(1) Remove the screws (6) and the washers (5).
(2) Remove the clamps (3) and (7) and the pipe assembly (4).
(3) Remove and discard the packings (1) and (8).
(4) Put the PLUG-BLANKING in each disconnected line end.

[Rev.10 from 2021] 2026.04.02 06:48:35 UTC