Removal of the Air Extraction Duct

TASK 21-26-41-000-002-A
Removal of the Air Extraction Duct

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 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	CAP - BLANKING
No specific	AR	PLUG - BLANKING
No specific	AR	SAFETY CLIP - CIRCUIT BREAKER

B. Work Zones and Access Panels

ZONE/ACCESS	ZONE DESCRIPTION
824

C. Referenced Information

REFERENCE	DESIGNATION
TASK 24-42-00-861-001-A	Energize the Ground Service Network from the External Power
TASK 26-15-15-000-001-A	Removal of the Smoke Detector - Avionics Compartment
TASK 52-41-00-010-002-A	Open the Avionics Compartment Doors for Access
Air Extraction Duct

3. Job Set-up
Subtask 21-26-41-861-052-A

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.

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

Subtask 21-26-41-865-053-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
122VU	AIR COND/AVNCS/VENT/MONG	3HQ	Y17
** 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 21-26-41-010-052-A

C. Get Access
(1) Put the ACCESS PLATFORM 2M (6 FT) - ADJUSTABLE in position at access door 824.
(2) Open access door 824 (Ref. AMM TASK 52-41-00-010-002).

4. Procedure
Subtask 21-26-41-020-053-B

A. Removal of the Air Extraction Duct

CAUTION: MAKE SURE THAT THE ELECTRICAL CONNECTORS ARE CLEAN BEFORE YOU DISCONNECT OR CONNECT THEM. CONTAMINATION ON THE ELECTRICAL CONNECTORS CAN CAUSE DAMAGE TO EQUIPMENT.

(1) Disconnect the electrical connector (8):
(a) Disconnect the electrical connector (8) from the avionics compartment smoke-detector (7).
(b) Put the CAP-BLANKING on each disconnected electrical connector and receptacle.
(2) If necessary, remove the avionics compartment smoke-detector (7) (Ref. AMM TASK 26-15-15-000-001).
(3) Disconnect the pipe (4).
(4) Loosen the union (5) and remove it from the duct (18).
(5) Remove and discard the O-ring (6).
(6) Remove the clamps (2), (9), (13) and (16).
(7) Keep the clamps (2), (9), (13) and (16) and use them during the installation procedure.
(8) Move the flexible sleeves (3), (10), (14) and (17) on the ducts (1), (12) and (15) to release the flexible sleeves (3), (10), (14) and (17) from the duct (18).
(9) Pull the duct (18) away from the fan (11) and remove the duct (18).
(10) Put the PLUG-BLANKING in each disconnected line end.

[Rev.10 from 2021] 2026.04.01 06:39:58 UTC