Detailed Inspection of Oxygen Masks (out of box) with Harness Inflated

TASK 35-12-41-200-001-A
Detailed Inspection of Oxygen Masks (out of box) with Harness Inflated

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.

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

1. Reason for the Job
Refer to the MPD TASK: 351241-01
DETAILED INSPECTION OF OXYGEN MASKS (OUT OF BOX) WITH HARNESS INFLATED
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 35-00-00-860-001-A	Special Precautions When Working on a Gaseous Oxygen System
TASK 35-12-41-100-802-A	Cleaning of the Full-Face/Quick-Donning Oxygen Mask on Aircraft
TASK 35-12-41-200-002-A	Check of the Correct Position of the Mask Lock and Correct Torque of the Retaining Screw
TASK 35-12-41-400-002-A	Installation of the Full-Face/Quick-donning Oxygen-Mask
Adjustment of the Oxygen Mask Strap-Separator

3. Job Set-up
Subtask 35-12-41-860-052-A

A. Aircraft Maintenance Configuration
(1) Obey the special precautions when you do work on a gaseous oxygen system (Ref. AMM TASK 35-00-00-860-001).
(2) Energize the aircraft electrical circuits (Ref. AMM TASK 24-41-00-861-002).
(3) In the cockpit, on the OXYGEN section of the overhead control and indicating panel 21VU, push the CREW SUPPLY pushbutton switch (the OFF legend goes off).

Subtask 35-12-41-865-051-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 35-12-41-220-050-A

A. Visual Inspection (oxygen masks MF10 and MF20 series)

Adjustment of the Oxygen Mask Strap-Separator

(1) Remove the oxygen mask from the oxygen-mask stowage box.
(2) Make sure that the top protection film is not installed.
If installed, remove and discard it.

NOTE: This top protection film is no longer available.

(3) On the oxygen mask regulator, push and hold the harness inflation control-levers (red lugs):
(a) Make sure that the harness inflates.
(b) Make sure that the harness has no leaks.
(c) Make sure that the head straps and the buckles are in the correct condition.
(4) Release the harness inflation control-levers (red lugs):
(a) Make sure that the harness deflates.
(5) Make sure that the strap separators are in the correct position on the deflated harness.
(a) For oxygen masks MF10 series:

Do the check of values A and B.

(b) For oxygen masks MF20 series:

Do the check of the correct position of the strap separators on the printed marks.

(6) Make sure that the doors of the oxygen-mask stowage box open and close correctly.
(7) Visually examine the oxygen mask regulator and its supply lines.
(a) In the internal part of the oronasal cone:

Make sure that the mask lock is correctly installed in the recess of the oxygen mask.
Make sure that the red torque mark (locking varnish) on the retaining screw is in the correct condition.

(b) If the red torque mark (locking varnish) on the retaining screw is not in the correct condition, or if the mask lock is not correctly installed:

Do a check of the position of the mask lock and of the torque of the retaining screw (Ref. AMM TASK 35-12-41-200-002).

(8) Make sure that the microphone cable is in the correct condition.
(9) Do a detailed inspection for dirt and/or contamination of the oxygen mask and the oxygen-mask stowage box:

Make sure that the inner and outer parts of the visor of the oxygen mask are clean and in the correct condition.
Make sure that the harness and the oxygen mask regulator are clean and in the correct condition.
Make sure that the oxygen-mask stowage box is clean and in the correct condition.

(a) If you find dirt and/or contamination, clean as necessary:

The oxygen mask (Ref. AMM TASK 35-12-41-100-802), and/or
The oxygen-mask stowage box.

(10) Install the oxygen mask in its stowage box (Ref. AMM TASK 35-12-41-400-002).
(11) Do these steps again for all the oxygen masks installed.

5. Close-up
Subtask 35-12-41-860-053-A

A. Put the aircraft back to its initial configuration.
(1) In the cockpit, on the OXYGEN section of the overhead control and indicating panel 21VU, release the 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 01:04:14 UTC