Removal of the Crew Oxygen-Storage Cylinders

TASK 35-11-41-000-802-A
Removal of the Crew Oxygen-Storage Cylinders

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.

CAUTION: PUT DRY AND CLEAN METAL OR PLASTIC PLUGS ON ALL PIPES OR UNITS THAT YOU REMOVE TEMPORARILY. THEN PUT EACH PIPE OR UNIT IN A SEALED VINYL BAG. IF YOU DO NOT OBEY THESE INSTRUCTIONS, CONTAMINATION OF THE OXYGEN SYSTEM CAN OCCUR.

ZONE: 123
ZONE: 210
FIN: 5750HM1 ** ON A/C NOT FOR ALL
FIN: 5750HM2 ** 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	1	ACCESS PLATFORM 2M (6 FT)
No specific	AR	SAFETY CLIP - CIRCUIT BREAKER
No specific	AR	WARNING NOTICE(S)
FOR [5750HM1] (OXYGEN CYLINDER)
No specific	AR	BAG - VINYL
No specific	AR	PLUG - BLANKING, APPROVED FOR USE WITH OXYGEN
No specific	AR	TIE WRAP(S)
No specific	Torque wrench: range to between 4.520 and 3.955 m.daN (33.33 and 29.17 lbf.ft )
FOR [5750HM2] (OXYGEN CYLINDER)
No specific	AR	BAG - VINYL
No specific	AR	PLUG - BLANKING, APPROVED FOR USE WITH OXYGEN
No specific	AR	TIE WRAP(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
123	NOSE GEAR WELL
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
TASK 35-10-00-870-801-A	Depressurization of the Crew Oxygen System (Manual Shutoff Valve(s) of the Crew Oxygen-Storage Cylinder(s) is (are) Closed)
TASK 52-41-00-010-002-A	Open the Avionics Compartment Doors for Access
Crew Oxygen-Storage Cylinders

3. Job Set-up
Subtask 35-11-41-860-058-A ** ON A/C NOT FOR ALL

A. Aircraft Maintenance Configuration

WARNING: WHEN YOU DO WORK ON THE GASEOUS OXYGEN SYSTEM, MAKE SURE THAT YOU OBEY ALL THE APPLICABLE SAFETY PRECAUTIONS. IF YOU DO NOT OBEY THESE PRECAUTIONS, INJURY TO PERSONS AND/OR DAMAGE TO THE AIRCRAFT CAN OCCUR.

(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).

Subtask 35-11-41-865-058-A ** ON A/C NOT FOR ALL

B. 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

Subtask 35-11-41-010-052-A ** ON A/C NOT FOR ALL

C. Get Access
(1) Put an ACCESS PLATFORM 2M (6 FT) in position at access door 812.
(2) Open access door 812 (Ref. AMM TASK 52-41-00-010-002).
(3) Get access to the avionics compartment.

Subtask 35-11-41-860-055-B ** ON A/C NOT FOR ALL

D. Aircraft Maintenance Configuration

Crew Oxygen-Storage Cylinders ** ON A/C NOT FOR ALL

(1) Fully close the manual shutoff valve (25) of the crew oxygen-storage cylinder (8) (5750HM1).
(2) Put a WARNING NOTICE(S) in position to tell persons not to open the manual shutoff valve of the crew oxygen-storage cylinder (8) (5750HM1).
(3) Fully close the manual shutoff valve (25) of the crew oxygen-storage cylinder (20) (5750HM2).
(4) Put a WARNING NOTICE(S) in position to tell persons not to open the manual shutoff valve of the crew oxygen-storage cylinder (20) (5750HM2).

Subtask 35-11-41-614-051-A ** ON A/C NOT FOR ALL

E. Bleeding of the Crew Oxygen System
(1) Release the pressure from the crew oxygen system (Ref. AMM TASK 35-10-00-870-801).
(2) In the cockpit, on the OXYGEN section of overhead control and indicating panel 21VU:

Put a WARNING NOTICE(S) in position to tell persons not to push the CREW SUPPLY pushbutton switch.

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 35-11-41-020-055-B ** ON A/C NOT FOR ALL

A. Removal of the Crew Oxygen-Storage Cylinders

Crew Oxygen-Storage Cylinders ** ON A/C NOT FOR ALL

CAUTION: USE A SECOND WRENCH TO APPLY COUNTERTORQUE TO THE UNION WHEN YOU DISCONNECT/CONNECT EQUIPMENT FROM FLEXIBLE HOSES AND RIGID TUBING. IF YOU DO NOT USE THE SECOND WRENCH, THERE IS A RISK THAT YOU WILL CAUSE DAMAGE TO THE HOSES AND TUBES.

(1) FOR [5750HM1] (OXYGEN CYLINDER)
(a) Loosen the nut (2) and disconnect the oxygen pressure-regulator transmitter (1) from the oxygen supply outlet (31) of the valve assy (28).
(b) Put a PLUG - BLANKING, APPROVED FOR USE WITH OXYGEN on the disconnected connector at the nut (2).
(c) Remove the stowage cap (30) from the bag (29).
(d) Put the stowage cap (30) on the oxygen supply outlet (31).
(e) TORQUE the stowage cap (30) to between 4.520 and 3.955 m.daN (33.33 and 29.17 lbf.ft )

.
(f) Put the oxygen pressure-regulator transmitter (1) in a BAG - VINYL.
(g) Attach the oxygen pressure-regulator transmitter (1) to the adjacent frame and/or bracket(s) with TIE WRAP(S).
(h) Disconnect the union (11) from the overboard discharge outlet (27) of the valve assy (28) and discard the ring (12).
(i) Remove the stowage cap (26) from the bag (29).
(j) Put the stowage cap (26) on the overboard discharge outlet (27).
(k) Put a PLUG - BLANKING, APPROVED FOR USE WITH OXYGEN on the union (11).
(l) Put the end of the overboard discharge hose (10) in a BAG - VINYL.
(m) Loosen the two nuts (5) and disengage the two pins (4) from the hooks of the clamps (3).
(n) Open the clamps (3) and (6) and remove the crew oxygen-storage cylinder (8) (5750HM1) from its support.
(2) FOR [5750HM2] (OXYGEN CYLINDER)
(a) Loosen the nut (14) and disconnect the oxygen pressure-regulator transmitter (13) from the oxygen supply outlet (31) of the valve assy (28).
(b) Put a PLUG - BLANKING, APPROVED FOR USE WITH OXYGEN on the disconnected connector at the nut (14).
(c) Remove the stowage cap (30) from the bag (29).
(d) Put the stowage cap (30) on the oxygen supply outlet (31).
(e) TORQUE the stowage cap (30) to between 4.520 and 3.955 m.daN (33.33 and 29.17 lbf.ft )

.
(f) Put the oxygen pressure-regulator transmitter (13) in a BAG - VINYL.
(g) Attach the oxygen pressure-regulator transmitter (13) to the adjacent frame and/or bracket(s) with TIE WRAP(S).
(h) Disconnect the union (22) from the overboard discharge outlet (27) of the valve assy (28) and discard the ring (24).
(i) Remove the stowage cap (26) from the bag (29).
(j) Put the stowage cap (26) on the overboard discharge outlet (27).
(k) Put a PLUG - BLANKING, APPROVED FOR USE WITH OXYGEN on the union (22).
(l) Put the end of the overboard discharge hose (23) in a BAG - VINYL.
(m) Loosen the two nuts (16) and disengage the two pins (17) from the hooks of the clamps (18).
(n) Open the clamps (15) and (18) and remove the crew oxygen-storage cylinder (20) (5750HM2) from its support.

[Rev.10 from 2021] 2026.04.01 04:42:45 UTC