OXY ON flag on the Mask Stowage Box Inoperative

TASK 35-10-00-810-809-A
OXY ON flag on the Mask Stowage Box Inoperative

1. Possible Causes

STOWAGE BOX-OXY MASK, CAPT [10RN1]
STOWAGE BOX-OXY MASK, F/O [10RN2]
STOWAGE BOX-OXY MASK, 3RD OCCPNT [10RN3]
STOWAGE BOX-OXY MASK, 4TH OCCPNT [5774HM]

2. Job Set-up Information
A. Referenced Information

REFERENCE	DESIGNATION
AMM 24-41-00-861-002	Energize the Aircraft Electrical Circuits from the External Power
AMM 24-41-00-862-002	De-energize the Aircraft Electrical Circuits Supplied from the External Power
AMM 35-12-41-000-001	Removal of the Oxygen-Mask Stowage-Box
AMM 35-12-41-400-001	Installation of the Oxygen-Mask Stowage-Box

3. Fault Confirmation
Subtask 35-10-00-860-054-A

A. Job Set Up
(1) Aircraft Maintenance Configuration
(a) Energize the aircraft electrical circuits
AMM 24-41-00-861-002.
(b) On the panel 21VU push the OXYGEN/CREW SUPPLY pushbutton switch (the OFF legend goes off).

Subtask 35-10-00-865-058-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

Subtask 35-10-00-710-058-A

C. Test
(1) Remove the oxygen mask.
(2) Make sure that the OXY ON flag on the mask stowage box is inoperative.

4. Fault Isolation
Subtask 35-10-00-810-058-B

A. If the OXY ON flag:
(1) On the Captain mask stowage box is inoperative with the mask out of the box:

replace the STOWAGE BOX-OXY MASK, CAPT [10RN1] AMM 35-12-41-000-001 and AMM 35-12-41-400-001.

(2) On the First Officer mask stowage box is inoperative with the mask out of the box:

replace the STOWAGE BOX-OXY MASK, F/O [10RN2] AMM 35-12-41-000-001 and AMM 35-12-41-400-001.

(3) On the Third Occupant mask stowage box is inoperative with the mask out of the box:

replace the STOWAGE BOX-OXY MASK, 3RD OCCPNT [10RN3] AMM 35-12-41-000-001 and AMM 35-12-41-400-001.

(4) On the Fourth Occupant mask stowage box is inoperative with the mask out of the box:

replace the STOWAGE BOX-OXY MASK, 4TH OCCPNT [5774HM] AMM 35-12-41-000-001 and AMM 35-12-41-400-001.

Subtask 35-10-00-710-059-A

B. Test
(1) Remove the oxygen mask.
(2) Make sure that the OXY ON flag on the mask stowage box is shown.

5. Close-up
Subtask 35-10-00-860-055-A

A. Put the aircraft back to its initial configuration.
(1) On the panel 21VU, release the OXYGEN/CREW SUPPLY pushbutton switch (the OFF legend comes on).
(2) De-energize the aircraft electrical circuits
AMM 24-41-00-862-002.

[Rev.8 from Aug 2018] 2026.04.04 04:33:35 UTC