Removal of the Crew Oxygen-Storage Cylinder

TASK 35-11-41-000-001-A
Removal of the Crew Oxygen-Storage Cylinder

WARNING: DO NOT FILL OR REPLACE A CREW OXYGEN CYLINDER OR REPLACE A VALVE ASSEMBLY ON THE CREW OXYGEN SYSTEM WHEN YOU FUEL OR DEFUEL THE AIRCRAFT. KEEP ALL HYDROCARBONS (FUELS, LUBRICANTS, ETC.) AWAY FROM ALL SOURCES 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: BE CAREFUL WHEN YOU REMOVE OR INSTALL THIS EQUIPMENT. THIS EQUIPMENT IS HEAVY (MORE THAN 12 KG (26.5 lb)) AND CAN CAUSE INJURY AND/OR DAMAGE.

ZONE: 125
ZONE: 210
FIN: 5750HM ** ON A/C NOT FOR ALL

1. Reason for the Job

NOTE: Two persons are necessary to do this task.

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

REFERENCE	QTY	DESIGNATION
No specific	AR	ACCESS PLATFORM 2M (6 FT)
No specific	AR	BAG - VINYL
No specific	AR	PLUG - BLANKING, APPROVED FOR USE WITH OXYGEN
No specific	AR	SAFETY CLIP - CIRCUIT BREAKER
No specific	AR	WARNING NOTICE(S)
No specific	Torque wrench: range to between 4.520 and 3.955 m.daN (33.33 and 29.17 lbf.ft )

B. Work Zones and Access Panels

ZONE/ACCESS	ZONE DESCRIPTION
125	LATERAL AVIONIC COMPARTMENT
210	CKPT,FWD COMPT BHD TO FLT COMPT BULKHEAD
812

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 35-00-00-860-001-A	Special Precautions When Working on a Gaseous Oxygen System
Crew Oxygen-Storage Cylinder ** ON A/C NOT FOR ALL
Crew Oxygen-Storage Cylinder ** ON A/C NOT FOR ALL
Oxygen Storage Cylinder ** ON A/C NOT FOR ALL

3. Job Set-up
Subtask 35-11-41-010-050-A ** ON A/C NOT FOR ALL

A. Get Access
(1) Put the ACCESS PLATFORM 2M (6 FT) in position at access door 812.
(2) Open access door 812.

Subtask 35-11-41-860-050-A ** ON A/C NOT FOR ALL

B. 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) Fully close the valve of the oxygen storage cylinder (5750HM).
(4) Put a WARNING NOTICE(S) in position to tell persons not to open the valve of the oxygen storage cylinder.

Subtask 35-11-41-614-050-A ** ON A/C NOT FOR ALL

C. Bleeding of the Oxygen System
(1) 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).
(2) On one oxygen-mask stowage box, push and hold the PRESS TO TEST AND RESET control lever.
At the same time, push and hold the PRESS TO TEST/EMERGENCY knob on the mask regulator.
(a) Keep them pushed for a minimum of three seconds.

NOTE: During this time, the flow rate indicator changes from yellow to black and the volume of the sound of the oxygen flow decreases.

(3) When the flow rate indicator is black and when you no longer hear the sound of the oxygen flow:

Release the PRESS TO TEST/EMERGENCY knob.
Release the PRESS TO TEST AND RESET control lever.

(4) Make sure that the PRESS TO TEST/EMERGENCY knob is not in the EMERGENCY position. If it is in the EMERGENCY position, there can be a leak of oxygen.
(5) 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).
Put a WARNING NOTICE(S) in position to tell persons not to push the CREW SUPPLY pushbutton switch.

Subtask 35-11-41-865-050-A ** ON A/C NOT FOR ALL

D. Open, safety and tag this(these) circuit breaker(s):

PANEL	DESIGNATION	FIN	LOCATION
** ON A/C NOT FOR ALL
49VU	OXYGEN/CREW/OXY/SPLY	1HT	HA01

4. Procedure

WARNING: SUPPORT THE UNIT/ASSEMBLY. THE UNIT/ASSEMBLY IS HEAVY. IF YOU DO NOT SUPPORT IT, IT WILL FALL. THIS CAN CAUSE INJURY TO PERSONS, AND/OR DAMAGE TO EQUIPMENT.

Subtask 35-11-41-020-053-B ** ON A/C NOT FOR ALL

A. Removal of the Crew Oxygen-Storage Cylinder (5750HM)

WARNING: SUPPORT THE UNIT/ASSEMBLY. THE UNIT/ASSEMBLY IS HEAVY. IF YOU DO NOT SUPPORT IT, IT WILL FALL. THIS CAN CAUSE INJURY TO PERSONS, AND/OR DAMAGE TO EQUIPMENT.

(1) Loosen the nut (4) and disconnect the oxygen pressure-regulator transmitter (3) from the valve (6).
(2) Put the PLUG - BLANKING, APPROVED FOR USE WITH OXYGEN on the nut (4) of the oxygen pressure-regulator transmitter (3).
(3) Put the oxygen pressure-regulator transmitter (3) in a BAG - VINYL.
(4) Remove the sealing cap (2) from the bag (11).
(5) Put the sealing cap (2) on the cylinder valve outlet-port (5).
(6) TORQUE the sealing cap (2) to between 4.520 and 3.955 m.daN (33.33 and 29.17 lbf.ft )

.
(7) Disconnect the union (8) from the overpressure outlet port (10).
(8) Discard the ring (7).
(9) Put the PLUG - BLANKING, APPROVED FOR USE WITH OXYGEN on the union (8).
(10) Remove the sealing cap (9) from the bag (11).
(11) Put the sealing cap (9) on the overpressure outlet port (10).
(12) Remove the nuts (14) and the washers (13) and disengage the collar assembly (12) from the support (22).
(13) Remove the nut (16) and the spacer (27).
(14) Disengage the pin (25) from the clamp (19).
(15) Open the clamps (19) and (24) and remove the crew oxygen-storage cylinder (1) from the support (22).

Subtask 35-11-41-020-053-E ** ON A/C NOT FOR ALL

A. Removal of the Crew Oxygen-Storage Cylinder (5750HM)
(1) Loosen the nut (3) and disconnect the oxygen pressure-regulator transmitter (2) from the valve (6).
(2) Put a PLUG - BLANKING, APPROVED FOR USE WITH OXYGEN on the oxygen pressure-regulator transmitter (2).
(3) Put the oxygen pressure-regulator transmitter (2) in a BAG - VINYL.
(4) Remove the sealing cap (4) from the bag (8).
(5) Put the sealing cap (4) on the cylinder valve outlet-port (5).
(6) TORQUE the sealing cap (4) to between 4.520 and 3.955 m.daN (33.33 and 29.17 lbf.ft )

.
(7) Disconnect the union (10) from the cylinder valve outlet-port (7), remove and discard the ring (9).
(8) Put a PLUG - BLANKING, APPROVED FOR USE WITH OXYGEN on the union (10).
(9) Put an oxygen cylinder stowage-cap on the cylinder valve outlet-port (7) and tighten it.
(10) Loosen the nut (12) and disengage the pin (11) from the clamp (14).
(11) Open the clamps (13) and (14) and remove the oxygen storage cylinder (1) from the support (15).

[Rev.10 from 2021] 2026.04.01 01:03:55 UTC