ADIRU/AVNCS VENT Caution Light Inoperative

TASK 21-26-00-040-012-A
ADIRU/AVNCS VENT Caution Light Inoperative

1. Reason for the Job
MMEL 24-30-09A
EXTERNAL POWER PANEL ADIRU/AVNCS VENT CAUTION LIGHT (FAA ONLY)
2. Job Set-up Information
A. Fixtures, Tools, Test and Support Equipment

REFERENCE	QTY	DESIGNATION
No specific	AR	WARNING NOTICE(S)

B. Referenced Information

REFERENCE	DESIGNATION
TASK 24-41-00-861-002-A	Energize the Aircraft Electrical Circuits from the External Power
TASK 24-41-00-861-002-A-01	Energize the Aircraft Electrical Circuits from the APU
TASK 24-41-00-861-002-A-02	Energize the Aircraft Electrical Circuits from Engine 1(2)
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)

3. Job Set-up
Subtask 21-26-00-865-100-A

A. Make sure that this(these) circuit breaker(s) is(are) closed:

PANEL	DESIGNATION	FIN	LOCATION
** ON A/C ALL
49VU	ENGINE/2/FADEC A/AND EIU 2	2KS2	A05
49VU	ENGINE/1/FADEC A/AND EIU 1	2KS1	A04
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 21-26-00-861-086-A

B. Energize the aircraft electrical circuits
(Ref. AMM TASK 24-41-00-861-002).

NOTE: The energization of the aircraft electrical circuits starts a full test of the ventilation system. The test continues for 2 minutes approximately.

Subtask 21-26-00-860-066-A

C. Aircraft Maintenance Configuration
(1) On the VENTILATION section of the panel 22VU:

make sure that the BLOWER and the EXTRACT pushbutton switches are in the AUTO configuration (pushed, with the FAULT and OVRD legends off).

4. Procedure
Subtask 21-26-00-710-069-A

A. Operational Test of the Mechanic Call Horn

ACTION	RESULT
1.On the circuit breaker panels 49VU and 122VU: open the circuit breakers 3HQ, 5HQ and 6HQ.	On the CAPT and F/O glareshield panels 131VU and 130VU: the MASTER CAUT lights come on and you can hear the single chime. After 30 seconds approximately: you can hear the mechanic call horn in the nose landing gear well. NOTE: The mechanic call horn operates only if engine 1 and engine 2 are stopped. NOTE: On the panel 108VU, push the RESET pushbutton switch to stop the mechanic call horn.
2.On the circuit breaker panels 49VU and 122VU: Close the circuit breakers 3HQ, 5HQ and 6HQ.

5. Close-up
Subtask 21-26-00-942-085-A

A. Safety Precautions
(1) Put WARNING NOTICE(S) in position in the cockpit to tell the crew that the ADIRU/AVNCS VENT caution light is inoperative.
(2) Make an entry in the logbook.

Subtask 21-26-00-862-088-A

B. Aircraft Maintenance Configuration
(1) De-energize the aircraft electrical circuits
(Ref. AMM TASK 24-41-00-862-002).

[Rev.10 from 2021] 2026.04.02 06:11:00 UTC