Removal of the Primary Heat Exchanger

TASK 21-52-25-000-001-A
Removal 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 is the same for the primary heat exchanger 10HM6 and 11HM6.

FIN: 10HM6
FIN: 11HM6

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	SAFETY CLIP - CIRCUIT BREAKER

B. Work Zones and Access Panels

ZONE/ACCESS	ZONE DESCRIPTION
FOR [10HM6] (HEAT EXCHANGER-PRIMARY)
191KB
FOR [11HM6] (HEAT EXCHANGER-PRIMARY)
192KB

C. Referenced Information

REFERENCE	DESIGNATION
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 53-35-13-000-002-A	Removal of the Quick-Release Access Panels from the Belly Fairing Structure
Primary Heat Exchanger 10HM6 (11HM6) - Component Location

3. Job Set-up
Subtask 21-52-25-865-050-A

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

PANEL	DESIGNATION	FIN	LOCATION
** ON A/C NOT FOR ALL
FOR FIN: 10HM6 (HEAT EXCHANGERPRIMARY)
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: 11HM6 (HEAT EXCHANGERPRIMARY)
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 21-52-25-010-050-A

B. Get Access
(1) Remove the access panel/s (Ref. AMM TASK 53-35-13-000-002).
(a) FOR [10HM6] (HEAT EXCHANGER-PRIMARY)

191KB,

(b) FOR [11HM6] (HEAT EXCHANGER-PRIMARY)

192KB.

4. Procedure
Subtask 21-52-25-020-050-A

A. Removal of the Primary Heat Exchanger
(1) Remove the heat exchanger unit (Ref. AMM TASK 21-52-24-000-001).
(2) Remove the screws (2), washers (3), fan plenum (1) and gasket (4) (if installed).
(3) Remove the screws (8), the washers (7) and the primary heat exchanger (5).
(4) Remove the gasket (6) (if installed).
(5) Put the protective covers on the cooling elements of the primary heat exchanger (5) and the main heat exchanger (9).

[Rev.10 from 2021] 2026.04.02 06:47:32 UTC