Installation of the Primary Heat Exchanger
TASK 21-52-25-400-001-A
Installation of the Primary Heat Exchanger
Self explanatory
2. Job Set-up Information
A. Fixtures, Tools, Test and Support Equipment
B. Work Zones and Access Panels
C. Referenced Information
3. Job Set-up
Subtask 21-52-25-865-051-A
Subtask 21-52-25-420-050-A
Subtask 21-52-25-410-050-A
[Rev.10 from 2021]
2026.04.02 06:11:29 UTC
Installation 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.
1. Reason for the JobSelf explanatory
2. Job Set-up Information
A. Fixtures, Tools, Test and Support Equipment
| REFERENCE | QTY | DESIGNATION |
|---|---|---|
| No specific | Torque wrench: range to between 0.45 and 0.4 m.daN (39.82 and 35.40 lbf.in ) ![]() |
| ZONE/ACCESS | ZONE DESCRIPTION |
|---|---|
| FOR [10HM6] (HEAT EXCHANGER-PRIMARY) | |
| 191KB | |
| FOR [11HM6] (HEAT EXCHANGER-PRIMARY) | |
| 192KB | |
| REFERENCE | DESIGNATION |
|---|---|
| TASK 12-33-21-618-001-A-01 | Pre-conditioning through the HP Ground Connection |
| TASK 12-33-21-618-001-A-02 | Pre-conditioning with the APU |
| TASK 21-52-24-400-001-A | Installation of the Heat Exchanger Unit (into the Aircraft) |
| TASK 21-52-24-400-001-A-01 | Installation of the Heat Exchanger Unit (Into the Air Conditioning Pack) |
| 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 53-35-13-000-002-A | Removal of the Quick-Release Access Panels from the Belly Fairing Structure |
| TASK 53-35-13-400-002-A | Installation of the Quick-Release Access Panels on the Belly Fairing Structure |
Subtask 21-52-25-865-051-A
A. Make sure that this(these) circuit breaker(s) is(are) open, safetied and tagged:
Subtask 21-52-25-860-050-A | 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 |
B. Aircraft Maintenance Configuration
(1) Make sure that the access panel/s is/are removed (Ref. AMM TASK 53-35-13-000-002).
(a) FOR [10HM6] (HEAT EXCHANGER-PRIMARY)
(b) FOR [11HM6] (HEAT EXCHANGER-PRIMARY)
4. Procedure(1) Make sure that the access panel/s is/are removed (Ref. AMM TASK 53-35-13-000-002).
(a) FOR [10HM6] (HEAT EXCHANGER-PRIMARY)
(b) FOR [11HM6] (HEAT EXCHANGER-PRIMARY)
Subtask 21-52-25-420-050-A
A. Installation of the Primary Heat Exchanger
(2) Make sure that the parts retained from the removed component are clean and in the correct condition.
(3) Clean the component interfaces and the adjacent area.
(4) Put the primary heat exchanger (5) in position on the main heat exchanger (9) and install the washers (7) and the screws (8).
(5) TORQUE the screws (8) to between 0.45 and 0.4 m.daN (39.82 and 35.40 lbf.in )
.
(6) Put the fan plenum (1) in position on the primary heat exchanger (5) and install the washers (3) and the screws (2).
(7) TORQUE the screws (2) to between 0.45 and 0.4 m.daN (39.82 and 35.40 lbf.in )
.
(8) Install the heat exchanger unit (Ref. AMM TASK 21-52-24-400-001).
Subtask 21-52-25-865-052-A NOTE: It is not necessary to install the gaskets (4) and (6) during the installation of the primary heat exchanger.
(1) Remove the protective covers from the cooling elements of the primary heat exchanger (5) and the main heat exchanger (9). (2) Make sure that the parts retained from the removed component are clean and in the correct condition.
(3) Clean the component interfaces and the adjacent area.
(4) Put the primary heat exchanger (5) in position on the main heat exchanger (9) and install the washers (7) and the screws (8).
(5) TORQUE the screws (8) to between 0.45 and 0.4 m.daN (39.82 and 35.40 lbf.in )
. (6) Put the fan plenum (1) in position on the primary heat exchanger (5) and install the washers (3) and the screws (2).
(7) TORQUE the screws (2) to between 0.45 and 0.4 m.daN (39.82 and 35.40 lbf.in )
. (8) Install the heat exchanger unit (Ref. AMM TASK 21-52-24-400-001).
B. Remove the safety clip(s) and the tag(s) and close this(these) circuit breaker(s):
Subtask 21-52-25-710-050-A | 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 |
C. Test
(1) Do the pre-conditioning through the HP ground connector or with the APU (Ref. AMM TASK 12-33-21-618-001) (Ref. AMM TASK 12-33-21-618-001).
(2) Do a leak check of the primary heat exchanger connections.
5. Close-up(1) Do the pre-conditioning through the HP ground connector or with the APU (Ref. AMM TASK 12-33-21-618-001) (Ref. AMM TASK 12-33-21-618-001).
(2) Do a leak check of the primary heat exchanger connections.
NOTE: Minimum leakage is permitted. After the pack operates some minutes, the leakage of air will reduce because the seals have their correct operating temperature.
(3) After approx. 15 minutes stop the pre-conditioning (Ref. AMM TASK 12-33-21-618-001) (Ref. AMM TASK 12-33-21-618-001). Subtask 21-52-25-410-050-A
A. Close Access
(1) Install the access panel/s (Ref. AMM TASK 53-35-13-400-002).
(a) FOR [10HM6] (HEAT EXCHANGER-PRIMARY)
(b) FOR [11HM6] (HEAT EXCHANGER-PRIMARY)
Subtask 21-52-25-862-050-A (1) Install the access panel/s (Ref. AMM TASK 53-35-13-400-002).
(a) FOR [10HM6] (HEAT EXCHANGER-PRIMARY)
(b) FOR [11HM6] (HEAT EXCHANGER-PRIMARY)
Primary Heat Exchanger 10HM6 (11HM6) - Component Location