Reactivation of the Conditioned-Air Inlet Valve and of the Blower Fan

TASK 21-26-00-440-013-A
Reactivation of the Conditioned-Air Inlet Valve and of the Blower Fan

1. Reason for the Job
MMEL 12-34-56C
AVIONICS BLOWER FAN (FUNC-CODE:21-26-01 ITEM-LIST-NBR:01)
MMEL 21-26-01C
AVIONICS BLOWER FAN
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	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 24-42-00-862-001-A	De-energize the Ground Service Network Supplied from the External Power
TASK 52-41-00-010-002-A	Open the Avionics Compartment Doors for Access
TASK 52-41-00-410-002-A	Close the Avionics Compartment Doors after Access

3. Job Set-up
Subtask 21-26-00-861-089-A

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

Subtask 21-26-00-865-102-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	5HQ	D05

Subtask 21-26-00-010-093-A

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

4. Procedure
Subtask 21-26-00-440-065-A

A. Reactivation of the Conditioned-Air Inlet Valve (21HQ) and of the Blower Fan
(1) On the conditioned-air inlet valve 21HQ:
(a) Get the electrical cable and its connector.
(b) Remove the CAP-BLANKING from each electrical connector and receptacle.
(c) Make sure that all the electrical connections are clean and in the correct condition.
(d) Connect the electrical connector 21HQ-A to the valve 21HQ.
(e) Fully close the valve 21HQ with the manual mechanism (the position indicator of the valve goes to C).
(2) On the VENTILATION section of the overhead panel 22VU:

Push the BLOWER pushbutton switch (the OVRD legend goes off.)

Subtask 21-26-00-865-103-A

B. Remove the safety clip(s) and the tag(s) and close this(these) circuit breaker(s):

PANEL	DESIGNATION	FIN	LOCATION
** ON A/C ALL
49VU	AIR COND/AVNCS VENT/CTL	5HQ	D05

5. Close-up
Subtask 21-26-00-410-090-A

A. Close Access
(1) Make sure that the work area is clean and clear of tools and other items.
(2) Close the access door 824 (Ref. AMM TASK 52-41-00-410-002).
(3) Remove the access platform(s).
(4) Remove the WARNING NOTICE(S).

Subtask 21-26-00-862-092-A

B. De-energize the ground service network
(Ref. AMM TASK 24-42-00-862-001).

[Rev.10 from 2021] 2026.04.02 06:10:59 UTC