Removal of the Air Cycle Machine

TASK 21-52-21-000-001-A
Removal of the Air Cycle Machine

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.

WARNING: BE CAREFUL WHEN YOU REMOVE OR INSTALL THIS EQUIPMENT. THIS EQUIPMENT IS HEAVY (MORE THAN 12 KG (26.5 lb)) AND CAN CAUSE INJURY AND/OR DAMAGE.

NOTE: The procedure is the same for air-cycle machines 10HM1 and 11HM1.

FIN: 10HM1
FIN: 11HM1

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 [10HM1] (MACHINE-AIR CYCLE)
191KB
FOR [11HM1] (MACHINE-AIR CYCLE)
192KB

C. Referenced Information

REFERENCE	DESIGNATION
TASK 21-52-21-200-001-A	Attachment Components (In-Service Wear Limits) - Air Cycle Machine
TASK 21-52-23-000-001-A	Removal of the Pipe Assembly between the Main Heat Exchanger and the Air Cycle Machine
TASK 21-61-53-000-001-A	Removal of the Turbine Bypass Valve
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
Air Cycle Machine 10HM1 (11HM1) ** ON A/C NOT FOR ALL
Air Cycle Machine 10HM1 (11HM1) ** ON A/C NOT FOR ALL
Attachment Components - Air Cycle Machine

3. Job Set-up
Subtask 21-52-21-861-052-A

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

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

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

PANEL	DESIGNATION	FIN	LOCATION
** ON A/C NOT FOR ALL
FOR FIN: 10HM1 (MACHINEAIR CYCLE)
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: 11HM1 (MACHINEAIR CYCLE)
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 21-52-21-941-050-A

C. Safety Precautions
(1) 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 a 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.

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

D. Get Access
(1) Remove these access panels from the belly fairing structure (Ref. AMM TASK 53-35-13-000-002):
(a) FOR [10HM1] (MACHINE-AIR CYCLE)

191KB.

(b) FOR [11HM1] (MACHINE-AIR CYCLE)

192KB.

(2) Remove the pipe assembly (Ref. AMM TASK 21-52-23-000-001).
(3) Remove bypass valve 10HH (11HH) (Ref. AMM TASK 21-61-53-000-001).

4. Procedure
Subtask 21-52-21-020-051-A

WARNING: USE GOGGLES AND GLOVES WHEN YOU REMOVE OR INSTALL LOCKWIRE. EACH TIME YOU CUT LOCKWIRE, REMOVE AND DISCARD IT IMMEDIATELY. LOOSE LOCKWIRE CAN CUT YOU OR MAKE YOU BLIND, AND/OR CAN CAUSE DAMAGE.

A. Removal of the Air Cycle Machine

Air Cycle Machine 10HM1 (11HM1) ** ON A/C NOT FOR ALL

(1) To prevent damage to the packings (6) and (15), turn the sleeves (7) and (16) when you move or install them.
(2) Remove the clamp (8), and disconnect the sleeve (9).
(3) Remove and discard the lockwire from the clamp (13) and the half clamps (14).
(4) Remove the clamp (5), and the half clamps (4).
(5) Move the sleeve (7) on the pipe assembly flange (2).
(6) Remove and discard the lockwire to remove the clamp (13) and the half clamps (14).
(7) Remove the clamp (13) and the half clamps (14).
(8) Move the sleeve (16) on the air-cycle machine flange (12).
(9) Remove the clamp (3).
(10) Remove the nut (28), the washer (27) and the screw (25), and disconnect the bonding strap (26).
(11) Disconnect the sense line (11).
(12) Remove the air cycle machine as follows:

WARNING: SUPPORT THE UNIT/ASSEMBLY. THE UNIT/ASSEMBLY IS HEAVY. IF YOU DO NOT SUPPORT IT, IT WILL FALL. THIS CAN CAUSE INJURY TO PERSONS, AND/OR DAMAGE TO EQUIPMENT.

(a) Hold the air cycle machine and remove the nuts (20), washers (21), bolts (24), (if installed, washers (23)) and bushings (22).
(b) Disconnect the support rods (74), (75), (78) and (79) and carefully remove the air cycle machine from the aircraft.

NOTE: The air cycle machine weighs approximately 22 kg (48.50 lb).

(13) Remove the clamp (10) and the sleeve (9).
(14) Remove and discard the packings (19), (6) and (15).
(15) Remove the sleeves (7) and (16).
(16) Put the PLUG-BLANKING in each disconnected line end.

Subtask 21-52-21-020-052-A

B. Removal of the Attachment Components

Attachment Components - Air Cycle Machine

(1) Record the positions of the support rods to use in the Installation procedure.
(2) Remove the nuts (20), washers (21), bolts (24), (if installed, washers (23)), bushings (22) and support rods (74), (75), (78) and (79).
(3) Do the inspection of the components for in-service wear (Ref. AMM TASK 21-52-21-200-001).

[Rev.10 from 2021] 2026.04.02 06:47:30 UTC