Operational Check of Flight Crew Oxygen System

TASK 35-12-41-710-001-A
Operational Check of Flight Crew Oxygen System

WARNING: KEEP ALL HYDROCARBONS (FUELS, LUBRICANTS, ETC.) AWAY FROM ALL SOURCE OF OXYGEN. OXYGEN BECOMES EXPLOSIVE WHEN IT TOUCHES HYDROCARBONS.

WARNING: CLEAN THE TOOLS AND MAKE SURE YOUR HANDS ARE CLEAN TO PREVENT CONTAMINATION OF THE OXYGEN SYSTEM.

WARNING: TELL ALL PERSONS THAT HAVE A HEADSET CONNECTED TO THE INTERCOM (MAINTENANCE AND GROUND CREWS) TO REMOVE THE HEADSET WHILE YOU DO THIS TEST. LOUD SOUND IS TRANSMITTED TO THE HEADSETS DURING THE TEST AND CAN CAUSE INJURY TO THE EARS.

CAUTION: BE CAREFUL WHEN YOU DO MAINTENANCE OF THE FULL-FACE/QUICK-DONNING MASK(S). YOU CAN CAUSE DAMAGE TO THIS EQUIPMENT VERY EASILY IF YOU USE TOO MUCH FORCE OR THE INCORRECT CLEANING MATERIALS.

ZONE: 210
FIN: 5757HM
FIN: 5758HM
FIN: 5759HM

1. Reason for the Job
Refer to the MPD TASK: 351000-01
OPERATIONAL CHECK OF FLIGHT CREW OXYGEN SYSTEM
Make sure that all the crew oxygen masks operate correctly.
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)

3. Job Set-up
Subtask 35-12-41-860-050-A

A. Aircraft Maintenance Configuration
(1) Energize the aircraft electrical circuits (Ref. AMM TASK 24-41-00-861-002).
(2) On the panel 21VU :

push the OXYGEN/CREW SUPPLY pushbutton switch (the OFF legend goes off).

Subtask 35-12-41-865-050-A

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

PANEL	DESIGNATION	FIN	LOCATION
** ON A/C ALL
49VU	OXYGEN/CREW/OXY/SPLY	1HT	HA01

4. Procedure
Subtask 35-12-41-710-050-A

A. Operational Test
(1) Do this operational test of all the full-face/quick-donning oxygen masks.

NOTE: The fourth occupant mask is not connected to the Audio Control Panel (ACP). Thus, the steps related to the ACP are not applicable to the fourth occupant mask.

ACTION	RESULT
1.On the CAPT ACP for the CAPT oxygen mask (only), installed on the left side: or On the F/O and the third occupant ACP for the oxygen mask(s) installed on the right side (F/O mask and third occupant mask) : Push the INT reception pushbutton switch and adjust the audio level to the minimum level that you can hear. Set the INT/RAD switch to INT.
2.On the stowage box door: Push the PRESS TO TEST AND RESET control slide. Hold it pushed during the test.	The yellow flow-rate indicator comes into view for a short time. You can hear the oxygen flow-rate for a short time: On the CAPT loudspeaker or headset for the mask(s) installed on the left side (CAPT mask) or On the F/O loudspeaker or headset for the mask(s) installed on the right side (F/O mask and third occupant mask).
3.On the full-face/quick-donning oxygen mask: Push and hold the PRESS TO TEST/EMERGENCY knob for 1 second.	The yellow flow-rate indicator comes into view. You can hear the oxygen flow-rate: On the CAPT loudspeaker or headset for the mask(s) installed on the left side (CAPT mask) or On the F/O loudspeaker or headset for the mask(s) installed on the right side (F/O mask and third occupant mask).
4.Release the PRESS TO TEST AND RESET control slide.
5.Operate the Normal/100% control and lock it in the 100% position.	The control operates correctly and locks correctly.
6.On the full-face quick-donning oxygen mask: Push and hold the PRESS TO TEST/EMERGENCY knob for 1 second.	The flow rate indicator does not come into view. You cannot hear the oxygen flow rate.
7.On the ACP of the station in maintenance : Push the INT reception pushbutton switch and adjust the audio level to the middle position Set the INT/RAD switch to the center position.

5. Close-up
Subtask 35-12-41-860-051-A

A. Put the aircraft back to its initial configuration.
(1) On the panel 21VU :

release the OXYGEN/CREW SUPPLY pushbutton switch (the OFF legend comes on).

(2) De-energize the aircraft electrical circuits (Ref. AMM TASK 24-41-00-862-002)

[Rev.10 from 2021] 2026.04.01 01:04:13 UTC