Check of the Correct Position of the Mask Lock and Correct Torque of the Retaining Screw

TASK 35-12-41-200-002-A
Check of the Correct Position of the Mask Lock and Correct Torque of the Retaining Screw

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
Self explanatory
2. Job Set-up Information
A. Fixtures, Tools, Test and Support Equipment

REFERENCE	QTY	DESIGNATION
No specific	Torque wrench: range to between 0.066 and 0.060 m.daN (5.84 and 5.31 lbf.in )
No specific	Torque wrench: range to between 0.13 and 0.12 m.daN (11.50 and 10.62 lbf.in )

B. Work Zones and Access Panels

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

C. 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 35-12-41-000-002-A	Removal of the Full-Face/Quick-Donning Oxygen-Mask
TASK 35-12-41-400-002-A	Installation of the Full-Face/Quick-donning Oxygen-Mask
Mask Lock and Retaining Screw

3. Job Set-up
Subtask 35-12-41-860-059-A

A. Aircraft Maintenance Configuration
(1) Energize the aircraft electrical circuits
(Ref. AMM TASK 24-41-00-861-002).
(2) On the OXYGEN section of the panel 21VU, push the CREW SUPPLY pushbutton switch (the OFF legend goes off).

Subtask 35-12-41-865-060-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 35-12-41-420-058-A

A. Check of the Correct Torque of the Retaining Screw

Mask Lock and Retaining Screw

(1) Remove the oxygen mask from its stowage box.
(2) If you can get access to the retaining screw (2):
(a) Loosen the retaining screw (2) from the mask lock (1).

PRE SB MF20-35-10
(b) TORQUE the retaining screw (2) to between 0.066 and 0.060 m.daN (5.84 and 5.31 lbf.in )

.
END OF PRE SB MF20-35-10

POST SB MF20-35-10
(c) TORQUE the retaining screw (2) to between 0.13 and 0.12 m.daN (11.50 and 10.62 lbf.in )

.
END OF POST SB MF20-35-10

(3) If you cannot get access to the retaining screw (2):
(a) Remove the oxygen mask from its stowage box (Ref. AMM TASK 35-12-41-000-002).
(b) Send the oxygen mask to the workshop to do the torque of the retaining screw (2).
(c) Install the oxygen mask in its stowage box (Ref. AMM TASK 35-12-41-400-002).

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

B. Check of the Correct Position of the Mask Lock

Mask Lock and Retaining Screw

(1) Make sure that the mask lock (1) is in the correct position.
(2) Install the oxygen mask in its stowage box.
(3) Make sure that the doors are correctly closed.

5. Close-up
Subtask 35-12-41-860-060-A

A. Put the aircraft back to its initial configuration.
(1) After you examined all the oxygen masks, on the OXYGEN section of the 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 01:04:16 UTC