Installation of Oxygen Masks in Decentralized Gaseous-Oxygen Container in the Lavatories

TASK 35-21-43-400-802-A
Installation of Oxygen Masks in Decentralized Gaseous-Oxygen Container in the Lavatories

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: 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.

WARNING: MAKE SURE THAT YOU OBEY THE MANUFACTURER'S INSTRUCTIONS AND NATIONAL HAZARDOUS MATERIAL REGULATIONS WHEN YOU MOVE OR KEEP THIS EQUIPMENT IN STORAGE:

CHEMICAL OXYGEN GENERATORS
PROTECTIVE BREATHING EQUIPMENT
FIXED AND PORTABLE OXYGEN CYLINDERS.

SPECIAL PRECAUTIONS ARE NECESSARY FOR THIS EQUIPMENT.

ZONE: 200

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

REFERENCE	QTY	DESIGNATION
No specific	1	GLOVES - COTTON, LINT-FREE, CLEAN
No specific	AR	WARNING NOTICE(S)

B. Work Zones and Access Panels

ZONE/ACCESS	ZONE DESCRIPTION
200	UPPER HALF FUSELAGE

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 35-00-00-860-001-A	Special Precautions When Working on a Gaseous Oxygen System
TASK 35-21-41-400-001-A	Installation of the Emergency Oxygen Containers
TASK 35-21-43-550-802-A	Packing of the Oxygen Mask Assemblies in Decentralized Gaseous-Oxygen Container
Emergency Oxygen Mask - Removal/Installation

3. Job Set-up
Subtask 35-21-43-860-056-A ** ON A/C NOT FOR ALL

A. Aircraft Maintenance Configuration
(1) Obey the special precautions when you do work on gaseous oxygen system (Ref. AMM TASK 35-00-00-860-001).
(2) Make sure that the aircraft electrical circuits are energized (Ref. AMM TASK 24-41-00-861-002).
(3) Make sure that a WARNING NOTICE(S) is in position in the cockpit to tell persons not to operate the emergency oxygen system.

Subtask 35-21-43-865-060-A ** ON A/C NOT FOR ALL

B. Make sure that this(these) circuit breaker(s) is(are) open, safetied and tagged:

PANEL	DESIGNATION	FIN	LOCATION
** ON A/C NOT FOR ALL
49VU	OXYGEN/PASSENGER/ACTUATION	7WR	HA08
49VU	OXYGEN/PASSENGER/ACTUATION	6WR	HA07
49VU	OXYGEN/PASSENGER/ACTUATION	5WR	HA06
49VU	OXYGEN/PASSENGER/ACTUATION	4WR	HA05
49VU	OXYGEN/PASSENGER/CTL AND WARN	3WR	HA04
49VU	OXYGEN/PASSENGER/CTL AND WARN	2WR	HA03
49VU	OXYGEN/PASSENGER/CTL AND WARN	1WR	HA02

Subtask 35-21-43-940-050-A ** ON A/C NOT FOR ALL

C. Preparation for the Installation of the Oxygen Mask Assemblies:
(1) Clean the component interfaces and the adjacent area.
(2) Do an inspection of the component interfaces and the adjacent area.
(3) Make sure that the parts retained from the removed component are clean and in the correct condition.

4. Procedure
Subtask 35-21-43-420-053-A ** ON A/C NOT FOR ALL

A. Installation of the Oxygen Mask Assemblies

Emergency Oxygen Mask - Removal/Installation ** ON A/C NOT FOR ALL

(1) Use GLOVES - COTTON, LINT-FREE, CLEAN when you install the oxygen mask assemblies.
(2) Make sure that the ejector strip (11) is removed from the slot of the oxygen container (10).
(3) Make sure that the safety pin with the warning flag (8) is installed and closed.
(4) Measure the length of the supply hoses (3) of the oxygen mask assemblies (1) that you will install.
(5) Make sure that the length of the supply hoses (3) is between 48 in. (1.22 m) and 49 in. (1.24 m). Do not install supply hoses (3) with a length less than 48 in. (1.2192 m).
(6) Connect the supply hoses (3) to the manifolds (6):

CAUTION: WHEN YOU INSTALL THE SUPPLY HOSES FOR THE OXYGEN MASKS ON THE MANIFOLD OUTLET, DO NOT APPLY FORCE LATERALLY TO THE OUTLET AXIS. THIS IS TO PREVENT DAMAGE TO THE MANIFOLD.

(a) Hold the manifold (6) tightly during installation of the supply hoses (3).
(b) Carefully push each supply hose (3) onto its related outlet (5).

NOTE: When the supply hose is installed correctly, there is a 2 mm (0.08 in.) distance between the supply hose and the body of manifold.

(7) Put the metallic ring of one mask lanyard (4) in the eyelet of the release pin (7).
(8) Install the metallic ring of the remaining mask lanyard (4) on the release pin (7).
(9) If applicable, connect the red flag "PULL" (16) to the snap hook of the oxygen mask lanyard (4).
(10) Push the release pin (7) through the hole in the actuator housing (12).
(11) Removal of the safety pin with the warning flag (8):
(a) Open the safety pin with the warning flag (8).
(b) Carefully remove the safety pin with a warning flag (8).
(12) Put the end of the ejector strip (11) into the slot of the oxygen container (10).
(a) Make sure that the printed CAUTION information shows face up to the the door (13).
(13) Put the oxygen mask assemblies (1) into the oxygen container (10) and close the oxygen container door (13) (Ref. AMM TASK 35-21-43-550-802).

5. Close-up
Subtask 35-21-43-410-053-A ** ON A/C NOT FOR ALL

A. Close Access

Emergency Oxygen Mask - Removal/Installation ** ON A/C NOT FOR ALL

(1) Install the oxygen container (10) (Ref. AMM TASK 35-21-41-400-001).
(2) Make sure that the work area is clean and clear of tools and other items.

Subtask 35-21-43-865-061-A ** ON A/C NOT FOR ALL

B. Remove the safety clip(s) and the tag(s) and close this(these) circuit breaker(s):

PANEL	DESIGNATION	FIN	LOCATION
** ON A/C NOT FOR ALL
49VU	OXYGEN/PASSENGER/ACTUATION	7WR	HA08
49VU	OXYGEN/PASSENGER/ACTUATION	6WR	HA07
49VU	OXYGEN/PASSENGER/ACTUATION	5WR	HA06
49VU	OXYGEN/PASSENGER/ACTUATION	4WR	HA05
49VU	OXYGEN/PASSENGER/CTL AND WARN	3WR	HA04
49VU	OXYGEN/PASSENGER/CTL AND WARN	2WR	HA03
49VU	OXYGEN/PASSENGER/CTL AND WARN	1WR	HA02

Subtask 35-21-43-860-057-A ** ON A/C NOT FOR ALL

C. Put the aircraft back to its initial configuration.
(1) In the cockpit, on the OXYGEN section of overhead panel 21VU:
(a) Remove the WARNING NOTICE(S).
(2) De-energize the aircraft electrical circuits
(Ref. AMM TASK 24-41-00-862-002).

[Rev.10 from 2021] 2026.04.01 01:05:06 UTC