Removal of the Inlet Duct and the Outlet Duct of the Skin Heat Exchanger

TASK 21-26-42-000-804-A
Removal of the Inlet Duct and the Outlet Duct of the Skin Heat Exchanger

CAUTION: BE VERY CAREFUL WHEN YOU DO WORK ON OR NEAR THE AIR-CONDITIONING DUCTS. THE DUCTS ARE MADE OF THIN MATERIAL AND YOU CAN EASILY BREAK THEM.

CAUTION: USE ONLY THE GROUND SERVICE NETWORK TO SUPPLY ELECTRICITY BECAUSE THE AVIONICS VENTILATION SYSTEM IS NOT SERVICEABLE. IF YOU ENERGIZE THE AIRCRAFT ELECTRICAL CIRCUITS WITHOUT THE VENTILATION SYSTEM YOU WILL CAUSE DAMAGE TO ELECTRICAL EQUIPMENT.

ZONE: 810
ZONE: 820

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	ACCESS PLATFORM 2M (6 FT) - ADJUSTABLE
No specific	AR	PLUG - BLANKING
No specific	AR	SAFETY CLIP - CIRCUIT BREAKER

B. Work Zones and Access Panels

ZONE/ACCESS	ZONE DESCRIPTION
810	AVIONICS COMPARTMENT DOORS (LEFT)
820	AVIONICS COMPT DOOR (RIGHT)
812, 822

C. Referenced Information

REFERENCE	DESIGNATION
TASK 24-42-00-861-001-A	Energize the Ground Service Network from the External Power
TASK 52-41-00-010-002-A	Open the Avionics Compartment Doors for Access
Inlet Duct of the Skin Heat Exchanger
Outlet Duct of the Skin Heat Exchanger

3. Job Set-up
Subtask 21-26-42-861-062-A

A. Energize the ground service network
(Ref. AMM TASK 24-42-00-861-001).

Subtask 21-26-42-865-071-A

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

PANEL	DESIGNATION	FIN	LOCATION
** ON A/C ALL
49VU	AIR COND/AVNCS VENT/CTL	6HQ	D06
49VU	AIR COND/AVNCS VENT/CTL	5HQ	D05
** ON A/C NOT FOR ALL
123VU	AVNCS VENT/EXTC/FAN	2HQ	AE02
** ON A/C ALL
123VU	AVNCS VENT/BLOWER/FAN	1HQ	AD10
** ON A/C NOT FOR ALL
123VU	AVNCS VENT/EXTC/FAN	2HQ	AC04

Subtask 21-26-42-010-068-A

C. Get Access
(1) Put an ACCESS PLATFORM 2M (6 FT) - ADJUSTABLE in position below the applicable access door 812 and/or 822.
(2) To get access to the inlet duct of the skin heat exchanger:
(a) Open access door 822 (Ref. AMM TASK 52-41-00-010-002).
(3) To get access to the outlet duct of the skin heat exchanger:
(a) Open access door 812 (Ref. AMM TASK 52-41-00-010-002).

4. Procedure
Subtask 21-26-42-020-062-B

A. Removal of the Inlet Duct of the Skin Heat Exchanger

Inlet Duct of the Skin Heat Exchanger

(1) Carefully move the insulating blankets away from the work area.
(2) Remove the clamps (9):
(a) Do not discard the clamps (9). You must keep and use them during the installation procedure.
(3) Move the flexible sleeve (14) on the duct (12).
(4) Remove the clamp (5).
(5) Remove the support clamp (8), which holds the duct (2):
(a) Attach the isolation valve (7) of the heat exchanger to the adjacent structure to prevent damage to the valve.
(6) Remove the attachment screws (10) and (4) and the washers (11) and (3).
(7) Carefully remove the ducts (2) and (12).
(8) Remove the seals (13) and (1).
(9) Remove and discard the O-ring (6) from the grooves of the isolation valve (7) of the heat exchanger.
(10) Remove the flexible sleeve (14) from the duct (12).
(11) Put the PLUG-BLANKING in each disconnected line end.

Subtask 21-26-42-020-063-B

B. Removal of the Outlet Duct of the Skin Heat Exchanger

Outlet Duct of the Skin Heat Exchanger

(1) Carefully move the insulating blankets away from the work area.
(2) Remove the clamps (8):
(a) Do not discard the clamps (8). You must keep and use them during the installation procedure.
(3) Move the flexible sleeve (9) on the duct (7).
(4) Remove the clamps (13):
(a) Do not discard the clamps (13). You must keep and use them during the installation procedure.
(5) Move flexible sleeve (14) on the duct (10).
(6) Remove the clamps (16):
(a) Do not discard the clamps (16). You must keep and use them during the installation procedure.
(7) Move the flexible sleeve (17) on the duct (2).
(8) Remove the support clamp (15).
(9) Remove the duct (2).
(10) Remove the attachment screws (6) and (11) and the washers (5) and (12).
(11) Carefully remove the ducts (7) and (10).
(12) Remove the seals (4) and (3).
(13) Remove the flexible sleeves (9), (14) and (17) from the ducts (7), (10) and (2).
(14) Put the PLUG-BLANKING in each disconnected line end.

[Rev.10 from 2021] 2026.04.02 06:11:03 UTC