Operational Test of the Oxygen Mask Microphone

TASK 23-51-00-710-004-A
Operational Test of the Oxygen Mask Microphone

ZONE: 210

1. Reason for the Job
To make sure that the Oxygen Mask Microphone operates
2. Job Set-up Information
A. Work Zones and Access Panels

ZONE/ACCESS	ZONE DESCRIPTION
210	CKPT,FWD COMPT BHD TO FLT COMPT BULKHEAD

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)
TASK 35-12-41-400-002-A	Installation of the Full-Face/Quick-donning Oxygen-Mask

3. Job Set-up
Subtask 23-51-00-860-067-A ** ON A/C NOT FOR ALL

A. Aircraft Maintenance Configuration
(1) Energize the aircraft electrical circuits. (Ref. AMM TASK 24-41-00-861-002)
(2) On all the ACPs, make sure that:

the INT/RAD selector switch is in the middle position
all the transmission pushbutton switches are pushed (no reception).

(3) On the maintenance panel 50VU, make sure that the SVCE INT OVRD pushbutton switch is not pushed.
(4) On the overhead control panel 48VU, make sure that the AUDIO SWITCHING selector switch is in the NORM position.
(5) At the CAPT, F/O and 3rd OCCPNT stations, connect a headset to the jack panel.
(6) On the CAPT, F/O and 3rd OCCPNT ACPs, push the INT transmission and INT reception pushbutton switches.

Subtask 23-51-00-860-067-B ** ON A/C NOT FOR ALL

A. Aircraft Maintenance Configuration
(1) Energize the aircraft electrical circuits. (Ref. AMM TASK 24-41-00-861-002)
(2) On all the ACPs, make sure that:

the INT/RAD selector switch is in the middle position
all the transmission pushbutton switches are pushed (no reception).

(3) On the maintenance panel 50VU, make sure that the SVCE INT OVRD pushbutton switch is not pushed.
(4) On the overhead control panel 48VU, make sure that the AUDIO SWITCHING selector switch is in the NORM position.
(5) At the CAPT, F/O, 3rd and 4th OCCPNT stations, connect a headset to the jack panel.
(6) On the CAPT, F/O, 3rd and 4th OCCPNT ACPs, push the INT transmission and INT reception pushbutton switches.

Subtask 23-51-00-865-067-A

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

PANEL	DESIGNATION	FIN	LOCATION
** ON A/C NOT FOR ALL
49VU	COM/AUDIO/ACP/F/O	5RN	G07
** ON A/C NOT FOR ALL
49VU	COM/AUDIO/FLT/INTPH	9RN	G08
49VU	COM/AUDIO/ACP/CAPT	4RN	G06
** ON A/C ALL
49VU	OXYGEN/CREW/OXY/SPLY	1HT	HA01
** ON A/C NOT FOR ALL
49VU	COM/ACP F/O/BITE/ INT 2 AUDIO/3&5 OCCPNT	5RN	G07
** ON A/C NOT FOR ALL
49VU	COM/INT/1+2	9RN	G08
49VU	COM/ACP CAPT/SELCAL/INT 1 AUDIO/AVNCS	4RN	G06
** ON A/C ALL
121VU	COM NAV/ACP/THIRD/OCCPNT	6RN	M02
** ON A/C NOT FOR ALL
121VU	COM NAV/ACP/FOURTH/OCCPNT	20RN	M01

4. Procedure
Subtask 23-51-00-710-064-A ** ON A/C NOT FOR ALL

A. Operational Test of the Oxygen Mask Microphone

NOTE: You must do the test at each crew station (refer to the data in parentheses).

NOTE: You must not push the MASK MAN ON pushbutton to avoid an unwanted release of the cabin oxygen-mask containers.

NOTE: Do not put oxygen mask fully against your face so that you do not use oxygen.

ACTION	RESULT
1.On the L overhead control panel 21VU: push the OXYGEN/CREW SUPPLY pushbutton switch.	On the OXYGEN/CREW SUPPLY pushbutton switch: the OFF legend goes off.
2.At the CAPT (F/O and 3rd OCCPNT) station: remove the mask from the stowage box	You can hear the oxygen flow rate.
3.On the CAPT (F/O, 3rd OCCPNT) ACP: set the INT/RAD selector switch to RAD and hold it in this position.
4.Speak into the oxygen mask microphone of the CAPT (F/O, 3rd OCCPNT) station.	Make sure that the reception is correct: in the headset at the CAPT, F/O and 3rd OCCPNT stations in the CAPT and F/O loud speakers (on the CAPT and F/O LOUD SPEAKER control panels 500VU and 301VU, the LOUD SPEAKER potentiometers are set to MAX).
5.On the CAPT (F/O, 3rd OCCPNT) ACP: release the INT/RAD selector switch.	On the CAPT (F/O, 3rd OCCPNT) ACP: the INT/RAD selector switch moves to the center position.
6.At the CAPT (F/O and 3rd OCCPNT) station: put the oxygen mask into the stowage box and close the doors. (Ref. AMM TASK 35-12-41-400-002)

Subtask 23-51-00-710-064-B ** ON A/C NOT FOR ALL

A. Operational Test of the Oxygen Mask Microphone

NOTE: You must do the test at each crew station (refer to the data in parentheses).

NOTE: You must not push the MASK MAN ON pushbutton to avoid an unwanted release of the cabin oxygen-mask containers.

NOTE: Do not put oxygen mask fully against your face so that you do not use oxygen.

ACTION	RESULT
1.On the L overhead control panel 21VU: push the OXYGEN/CREW SUPPLY pushbutton switch.	On the OXYGEN/CREW SUPPLY pushbutton switch: the OFF legend goes off.
2.At the CAPT (F/O, 3rd and 4th OCCPNT) station: remove the mask from the stowage box	You can hear the oxygen flow rate.
3.On the CAPT (F/O, 3rd and 4th OCCPNT) ACP: set the INT/RAD selector switch to RAD and hold it in this position.
4.Speak into the oxygen mask microphone of the CAPT (F/O, 3rd and 4th OCCPNT) station.	Make sure that the reception is correct: in the headset at the CAPT, F/O, 3rd and 4th OCCPNT stations in the CAPT and F/O loud speakers (on the CAPT and F/O LOUD SPEAKER control panels 500VU and 301VU, the LOUD SPEAKER potentiometers are set to MAX).
5.On the CAPT (F/O, 3rd and 4th OCCPNT) ACP: release the INT/RAD selector switch.	On the CAPT (F/O, 3rd and 4th OCCPNT) ACP: the INT/RAD selector switch moves to the center position.
6.At the CAPT (F/O, 3rd and 4th OCCPNT) station: put the oxygen mask into the stowage box and close the doors. (Ref. AMM TASK 35-12-41-400-002)

5. Close-up
Subtask 23-51-00-860-068-A ** ON A/C NOT FOR ALL

A. Put the Aircraft back to its Initial Configuration
(1) On the CAPT, F/O, 3rd OCCUPNT ACPs, push the INT transmission and INT reception pushbutton switches.
(2) At the CAPT, F/O, 3rd OCCPNT stations, disconnect the headset.
(3) De-energize the aircraft electrical circuits. (Ref. AMM TASK 24-41-00-862-002)

Subtask 23-51-00-860-068-B ** ON A/C NOT FOR ALL

A. Put the Aircraft back to its Initial Configuration
(1) On the CAPT, F/O, 3rd and 4th OCCPNT ACPs, push the INT transmission and INT reception pushbutton switches.
(2) At the CAPT, F/O, 3rd and 4th OCCPNT stations, disconnect the headset.
(3) De-energize the aircraft electrical circuits. (Ref. AMM TASK 24-41-00-862-002)

[Rev.10 from 2021] 2026.03.31 23:15:36 UTC