Removal of the Fan Plenum Chamber

TASK 21-52-22-000-001-A
Removal of the Fan Plenum Chamber

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 is the same for fan plenum chambers 10HM5 and 11HM5.

FIN: 10HM5
FIN: 11HM5

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	COVER - PROTECTION
No specific	AR	SAFETY CLIP - CIRCUIT BREAKER
No specific	AR	WARNING NOTICE(S)

B. Work Zones and Access Panels

ZONE/ACCESS	ZONE DESCRIPTION
FOR [10HM5] (PLENUM CHAMBER)
191KB
FOR [11HM5] (PLENUM CHAMBER)
192KB

C. Referenced Information

REFERENCE	DESIGNATION
TASK 21-52-23-000-001-A	Removal of the Pipe Assembly between the Main Heat Exchanger and the Air Cycle Machine
TASK 21-52-24-000-001-A	Removal of the Heat Exchanger Unit (from the Aircraft)
TASK 21-52-24-000-001-A-01	Removal of the Heat Exchanger Unit (From the Air Conditioning Pack)
TASK 21-61-52-000-003-A	Removal of the Ram-Air Outlet
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
Fan Plenum Chamber 10HM5 (11HM5) ** ON A/C NOT FOR ALL
Fan Plenum Chamber 10HM5 (11HM5) ** ON A/C NOT FOR ALL

3. Job Set-up
Subtask 21-52-22-861-051-A

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

Subtask 21-52-22-865-050-A

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

PANEL	DESIGNATION	FIN	LOCATION
** ON A/C NOT FOR ALL
FOR FIN: 10HM5 (PLENUM CHAMBER)
49VU	AIR COND/TEMP CTL/SYS 1 CHAN B/28VDC	52HH	D08
** ON A/C NOT FOR ALL
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
** ON A/C NOT FOR ALL
122VU	AIR COND/TEMP CTL SYS 1/CHAN A/115VAC	49HH	X22
122VU	AIR COND/TEMP CTL SYS 1/CHAN A/28VDC	51HH	X21
122VU	AIR COND/TEMP CTL SYS 1/CHAN B/115VAC	50HH	Y18
** ON A/C NOT FOR ALL
FOR FIN: 11HM5 (PLENUM CHAMBER)
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
** ON A/C NOT FOR ALL
122VU	AIR COND/TEMP CTL SYS 2/CHAN A/115VAC	53HH	W22
122VU	AIR COND/TEMP CTL SYS 2/CHAN A/28VDC	55HH	W21
122VU	AIR COND/TEMP CTL SYS 2/CHAN B/28VDC	56HH	Y21
122VU	AIR COND/TEMP CTL SYS 2/CHAN B/115VAC	54HH	Y20

Subtask 21-52-22-010-050-A

C. Get Access
(1) Remove the access panel (Ref. AMM TASK 53-35-13-000-002):
(a) FOR [10HM5] (PLENUM CHAMBER)

191KB.

(b) FOR [11HM5] (PLENUM CHAMBER)

192KB.

Subtask 21-52-22-941-050-A

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 21-52-22-020-051-A ** ON A/C NOT FOR ALL

A. Removal of the Fan Plenum Chamber
(1) Remove the ram air outlet(s) (Ref. AMM TASK 21-61-52-000-003).
(2) Disconnect and remove the clamp (4).
(3) Remove the bellow (5).
(4) Disconnect and remove the clamp (9).
(5) Disconnect the sleeve (10).
(6) Disconnect the bonding strap (8).

NOTE: This work step is only applicable to fan plenum-chamber part-numbers 1816A0000-01, 749A0000-02 Amdt B, 2056A0000-02 Amdt A, 2056B0000-01 Amdt A, 2056C0000-01 and 2056C0000-02.

(7) Remove the screw (2), the washer (3) and the bonding strap (8).
(8) Remove the screws (2), the washers (3) and the fan plenum chamber (1).
(9) If the gasket (6) is installed on the fan plenum chamber (1), remove the gasket (6).
(10) Put the COVER - PROTECTION on the cooling elements of the primary heat exchanger (7).

Subtask 21-52-22-020-051-C ** ON A/C NOT FOR ALL

A. Removal of the Fan Plenum Chamber
(1) Remove the ram air outlet/s (Ref. AMM TASK 21-61-52-000-003).
(2) Remove the pipe assembly/ies (Ref. AMM TASK 21-52-23-000-001).
(3) Remove heat exchanger unit/s 10HM4 (11HM4) (Ref. AMM TASK 21-52-24-000-001).

NOTE: It is not necessary to remove the inlet plenum at this time.

(4) Disconnect the bonding strap (7):

NOTE: This work step is only applicable to fan plenum chamber P/N 1816A0000-01.

(a) Remove the nut (10), the washer (9) and the screw (8) and disconnect the bonding strap (7).
(5) Remove the screws (1), the washers (2) and the fan plenum chamber (3).
(6) Put a COVER - PROTECTION on the cooling elements of the primary heat exchanger (5).

[Rev.10 from 2021] 2026.03.31 23:06:53 UTC