DOC AIRBUS | AMM A320FLoss of REGUL LO PR Indication
TASK 35-10-00-040-002-A
Loss of REGUL LO PR Indication
MMEL 35-07-02A
CREW OXYGEN REGUL LO PR INDICATION ON THE DOOR/OXY
The crew-oxygen REGUL LO PR indication on the DOOR/OXY page is incorrect if:
This task is to make sure that there is sufficient oxygen pressure in the oxygen system before the flight.
2. Job Set-up Information
A. Fixtures, Tools, Test and Support Equipment
B. Work Zones and Access Panels
C. Referenced Information
3. Job Set-up
Subtask 35-10-00-010-058-A ** ON A/C NOT FOR ALL
Subtask 35-10-00-720-050-A ** ON A/C NOT FOR ALL
Subtask 35-10-00-860-062-A ** ON A/C NOT FOR ALL
[Rev.10 from 2021]
2026.04.01 01:03:45 UTC
Loss of REGUL LO PR Indication
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 VERY CAREFUL WHEN YOU DO WORK ON OR NEAR THE AIR-CONDITIONING DUCTS. THE DUCTS ARE MADE OF THIN MATERIAL AND YOU CAN EASILY BREAK THEM.
1. Reason for the JobMMEL 35-07-02A
CREW OXYGEN REGUL LO PR INDICATION ON THE DOOR/OXY
The crew-oxygen REGUL LO PR indication on the DOOR/OXY page is incorrect if:
- The REGUL LO PR indication is continuously shown when the oxygen pressure is not low, or
- The REGUL LO PR indication is not shown when there is a low pressure condition.
This task is to make sure that there is sufficient oxygen pressure in the oxygen system before the flight.
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 | 1 | GAGE 10 BAR (145 PSI) - PRESSURE |
| No specific | AR | WARNING NOTICE(S) |
| 110111-03 | 1 | COUPLING-OXYGEN QUICK DISCONNECT |
| OR | OR | |
| 802857-01 | 1 | COUPLING |
| 98D35208729001 | 1 | TOOL-DPRESS, TEST-O2 |
| ZONE/ACCESS | ZONE DESCRIPTION |
|---|---|
| 123 | NOSE GEAR WELL |
| 125 | LATERAL AVIONIC COMPARTMENT |
| 210 | CKPT,FWD COMPT BHD TO FLT COMPT BULKHEAD |
| 812 |
| 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 52-41-00-010-002-A | Open the Avionics Compartment Doors for Access |
| TASK 52-41-00-410-002-A | Close the Avionics Compartment Doors after Access |
REGUL LO PR IndicationSubtask 35-10-00-010-058-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.
(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 (5750HM).
Subtask 35-10-00-010-058-B ** ON A/C NOT FOR ALL (1) Put the ACCESS PLATFORM 2M (6 FT) in position at access door 812.
(2) Open access door 812.
(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 (5750HM).
A. Get Access
(1) Put the ACCESS PLATFORM 2M (6 FT) in position at access door 812.
(2) Open access door 812 (Ref. AMM TASK 52-41-00-010-002).
Subtask 35-10-00-865-053-A (1) Put the ACCESS PLATFORM 2M (6 FT) in position at access door 812.
(2) Open access door 812 (Ref. AMM TASK 52-41-00-010-002).
B. Make sure that this(these) circuit breaker(s) is(are) closed:
Subtask 35-10-00-860-061-A ** ON A/C NOT FOR ALL | PANEL | DESIGNATION | FIN | LOCATION |
|---|---|---|---|
| ** ON A/C ALL | |||
| 49VU | OXYGEN/CREW/OXY/SPLY | 1HT | HA01 |
C. 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) Bleed the oxygen system:
(a) 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).
(b) Put a WARNING NOTICE(S) in position to tell persons not to release the CREW SUPPLY pushbutton switch.
(c) 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.
1 Keep them pushed for a minimum of three seconds.
Subtask 35-10-00-860-061-C ** ON A/C NOT FOR ALL (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) Bleed the oxygen system:
(a) 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).
(b) Put a WARNING NOTICE(S) in position to tell persons not to release the CREW SUPPLY pushbutton switch.
(c) 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.
1 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.
(d) 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.
C. 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) On the crew oxygen-storage cylinder 5750HM1 (1):
(a) Fully close the manual shutoff valve (2) of the crew oxygen-storage cylinder 5750HM1 (1).
(b) Put a WARNING NOTICE(S) in position to tell persons not to open the manual shutoff valve (2) of the crew oxygen-storage cylinder 5750HM1 (1).
(4) On the crew oxygen-storage cylinder 5750HM2 (3):
(a) Fully close the manual shutoff valve (4) of the crew oxygen-storage cylinder 5750HM2 (3).
(b) Put a WARNING NOTICE(S) in position to tell persons not to open the manual shutoff valve (4) of the crew oxygen-storage cylinder 5750HM2 (3).
Subtask 35-10-00-614-054-A ** ON A/C NOT FOR ALL (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) On the crew oxygen-storage cylinder 5750HM1 (1):
(a) Fully close the manual shutoff valve (2) of the crew oxygen-storage cylinder 5750HM1 (1).
(b) Put a WARNING NOTICE(S) in position to tell persons not to open the manual shutoff valve (2) of the crew oxygen-storage cylinder 5750HM1 (1).
(4) On the crew oxygen-storage cylinder 5750HM2 (3):
(a) Fully close the manual shutoff valve (4) of the crew oxygen-storage cylinder 5750HM2 (3).
(b) Put a WARNING NOTICE(S) in position to tell persons not to open the manual shutoff valve (4) of the crew oxygen-storage cylinder 5750HM2 (3).
D. Bleeding of the Two Oxygen Systems
(1) In the cockpit, on the OXYGEN section of the overhead control and indicating panel 21VU:
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.
(3) On the First-Officer oxygen-mask stowage-box, push and hold the PRESS TO TEST AND RESET control button.
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.
4. Procedure(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).
- Put a WARNING NOTICE(S) in position to tell persons not to release the CREW SUPPLY pushbutton switch.
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.
(b) When the flow rate indicator is black and when you can no longer hear the sound of the oxygen flow: - Release the PRESS TO TEST/EMERGENCY knob.
- Release the PRESS TO TEST AND RESET control button.
WARNING:
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.
1 Make sure that the PRESS TO TEST/EMERGENCY knob is not in the EMERGENCY position. (3) On the First-Officer oxygen-mask stowage-box, push and hold the PRESS TO TEST AND RESET control button.
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.
(b) When the flow rate indicator is black and when you can no longer hear the sound of the oxygen flow: - Release the PRESS TO TEST/EMERGENCY knob.
- Release the PRESS TO TEST AND RESET control button.
WARNING:
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.
1 Make sure that the PRESS TO TEST/EMERGENCY knob is not in the EMERGENCY position. Subtask 35-10-00-720-050-A ** ON A/C NOT FOR ALL
A. Check of the LP Oxygen of the Crew Oxygen Cylinder
(1) Remove the blanking cap from the oxygen-system test-port 5755HM.
(2) Connect the GAGE 10 BAR (145 PSI) - PRESSURE to the 110111-03 COUPLING-OXYGEN QUICK DISCONNECT802857-01 COUPLING or equivalent.
(3) Connect the 110111-03 COUPLING-OXYGEN QUICK DISCONNECT802857-01 COUPLING or equivalent to the oxygen-system test-port 5755HM.
(4) Fully open the valve of the oxygen storage cylinder 5750HM.
(5) Make sure that the pressure on the pressure gage is more than 50 psi (3.45 bar).
(6) Fully close the valve of the oxygen storage cylinder 5750HM.
(7) Bleed the oxygen system:
(a) 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.
1 Keep them pushed for a minimum of three seconds.
Subtask 35-10-00-720-050-C ** ON A/C NOT FOR ALL (1) Remove the blanking cap from the oxygen-system test-port 5755HM.
(2) Connect the GAGE 10 BAR (145 PSI) - PRESSURE to the 110111-03 COUPLING-OXYGEN QUICK DISCONNECT802857-01 COUPLING or equivalent.
(3) Connect the 110111-03 COUPLING-OXYGEN QUICK DISCONNECT802857-01 COUPLING or equivalent to the oxygen-system test-port 5755HM.
(4) Fully open the valve of the oxygen storage cylinder 5750HM.
(5) Make sure that the pressure on the pressure gage is more than 50 psi (3.45 bar).
(6) Fully close the valve of the oxygen storage cylinder 5750HM.
(7) Bleed the oxygen system:
(a) 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.
1 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.
(b) 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.
A. Check of the Low Pressure Oxygen of the Crew Oxygen-Storage Cylinders
(1) At oxygen-system test-port 5755HM1 (5):
(a) Remove the blanking cap (6) from oxygen-system test-port 5755HM1 (5).
(b) Connect one of these tools to oxygen-system test-port 5755HM1 (5):
(2) Do a check of the oxygen pressure as follows:
(a) Turn the manual shutoff valve.
(b) Wait one minute to make sure that the pressure is stable.
(c) Make sure that the oxygen pressure on the pressure gage is more than 50 psi (3.45 bar).
(3) Bleed the Captain oxygen system:
(a) On the crew oxygen-storage-cylinder 5750HM1 (1):
At the same time, push and hold the PRESS TO TEST/EMERGENCY knob on the mask regulator.
1 Keep them pushed for a minimum of three seconds.
(4) Disconnect the applicable tool from oxygen-system test-port 5755HM1 (5):
(5) At oxygen-system test-port 5755HM2 (5):
(a) Remove the blanking cap (6) from oxygen-system test-port 5755HM2 (5).
(b) Connect one of these tools to oxygen-system test-port 5755HM2 (5):
(6) Do a check of the oxygen pressure as follows:
(a) Turn the manual shutoff valve.
(b) Wait one minute to make sure that the pressure is stable.
(c) Make sure that the oxygen pressure on the pressure gage is more than 50 psi (3.45 bar).
(7) Bleed the First-Officer oxygen system:
(a) On crew oxygen-storage-cylinder 5750HM2 (3):
At the same time, push and hold the PRESS TO TEST/EMERGENCY knob on the mask regulator.
1 Keep them pushed for a minimum of three seconds.
(8) Disconnect and/or disassemble the applicable tool from oxygen-system test-port 5755HM2 (5):
Subtask 35-10-00-020-050-A ** ON A/C NOT FOR ALL (1) At oxygen-system test-port 5755HM1 (5):
(a) Remove the blanking cap (6) from oxygen-system test-port 5755HM1 (5).
(b) Connect one of these tools to oxygen-system test-port 5755HM1 (5):
- Assemble the GAGE 10 BAR (145 PSI) - PRESSURE and the 110111-03 COUPLING-OXYGEN QUICK DISCONNECT802857-01 COUPLING (or equivalent) and connect this assembly to the test-port.
- Connect the 98D35208729001 TOOL-DPRESS, TEST-O2 to the test port.
(2) Do a check of the oxygen pressure as follows:
(a) Turn the manual shutoff valve.
CAUTION:
WHEN YOU OPEN THE MANUAL SHUTOFF VALVE ON THE CREW OXYGEN-STORAGE CYLINDER, MAKE SURE THAT:
1 Turn the manual shutoff valve (2) of the crew oxygen-storage-cylinder 5750HM1 (1) very slowly until it is fully open. - YOU TURN IT VERY SLOWLY
- YOU TURN IT UNTIL IT IS FULLY OPEN.
(b) Wait one minute to make sure that the pressure is stable.
(c) Make sure that the oxygen pressure on the pressure gage is more than 50 psi (3.45 bar).
(3) Bleed the Captain oxygen system:
(a) On the crew oxygen-storage-cylinder 5750HM1 (1):
- Fully close the manual shutoff valve (2) of the crew oxygen-storage-cylinder 5750HM1 (1).
At the same time, push and hold the PRESS TO TEST/EMERGENCY knob on the mask regulator.
1 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.
2 When the flow rate indicator is black and when you can no longer hear the sound of the oxygen flow: - Release the PRESS TO TEST/EMERGENCY knob.
- Release the PRESS TO TEST AND RESET control button.
WARNING:
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.
a Make sure that the PRESS TO TEST/EMERGENCY knob is not in the EMERGENCY position. (4) Disconnect the applicable tool from oxygen-system test-port 5755HM1 (5):
- Disconnect the 110111-03 COUPLING-OXYGEN QUICK DISCONNECT802857-01 COUPLING (or equivalent) from the test-port.
NOTE: It is not necessary to disassemble the GAGE 10 BAR (145 PSI) - PRESSURE from the 110111-03 COUPLING-OXYGEN QUICK DISCONNECT802857-01 COUPLING (or equivalent) at this time.
Or disconnect this alternative tool: - Disconnect the 98D35208729001 TOOL-DPRESS, TEST-O2 from the test-port.
(5) At oxygen-system test-port 5755HM2 (5):
(a) Remove the blanking cap (6) from oxygen-system test-port 5755HM2 (5).
(b) Connect one of these tools to oxygen-system test-port 5755HM2 (5):
- Connect the 110111-03 COUPLING-OXYGEN QUICK DISCONNECT802857-01 COUPLING (or equivalent) with its GAGE 10 BAR (145 PSI) - PRESSURE to the test port.
- Connect the 98D35208729001 TOOL-DPRESS, TEST-O2 to the test port.
(6) Do a check of the oxygen pressure as follows:
(a) Turn the manual shutoff valve.
CAUTION:
WHEN YOU OPEN THE MANUAL SHUTOFF VALVE ON THE CREW OXYGEN-STORAGE CYLINDER, MAKE SURE THAT:
1 Turn the manual shutoff valve (4) of crew oxygen-storage-cylinder 5750HM2 (3) very slowly until it is fully open. - YOU TURN IT VERY SLOWLY
- YOU TURN IT UNTIL IT IS FULLY OPEN.
(b) Wait one minute to make sure that the pressure is stable.
(c) Make sure that the oxygen pressure on the pressure gage is more than 50 psi (3.45 bar).
(7) Bleed the First-Officer oxygen system:
(a) On crew oxygen-storage-cylinder 5750HM2 (3):
- Fully close the manual shutoff valve (4) of crew oxygen-storage-cylinder 5750HM2 (3).
- Release the CREW SUPPLY pushbutton switch (the OFF legend comes on).
At the same time, push and hold the PRESS TO TEST/EMERGENCY knob on the mask regulator.
1 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.
2 When the flow rate indicator is black and when you can no longer hear the sound of the oxygen flow: - Release the PRESS TO TEST/EMERGENCY knob.
- Release the PRESS TO TEST AND RESET control button.
WARNING:
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.
a Make sure that the PRESS TO TEST/EMERGENCY knob is not in the EMERGENCY position. (8) Disconnect and/or disassemble the applicable tool from oxygen-system test-port 5755HM2 (5):
- Disconnect the 110111-03 COUPLING-OXYGEN QUICK DISCONNECT802857-01 COUPLING (or equivalent) from the test port and disassemble it from the GAGE 10 BAR (145 PSI) - PRESSURE.
- Disconnect the 98D35208729001 TOOL-DPRESS, TEST-O2 from the test port.
B. Disconnect the Test Installation
(1) Remove the 110111-03 COUPLING-OXYGEN QUICK DISCONNECT802857-01 COUPLING or equivalent from the oxygen-system test-port 5755HM.
(2) Remove the GAGE 10 BAR (145 PSI) - PRESSURE from the 110111-03 COUPLING-OXYGEN QUICK DISCONNECT802857-01 COUPLING or equivalent.
(3) Put the blanking cap on the oxygen-system test-port 5755HM.
5. Close-up(1) Remove the 110111-03 COUPLING-OXYGEN QUICK DISCONNECT802857-01 COUPLING or equivalent from the oxygen-system test-port 5755HM.
(2) Remove the GAGE 10 BAR (145 PSI) - PRESSURE from the 110111-03 COUPLING-OXYGEN QUICK DISCONNECT802857-01 COUPLING or equivalent.
(3) Put the blanking cap on the oxygen-system test-port 5755HM.
Subtask 35-10-00-860-062-A ** ON A/C NOT FOR ALL
A. Put the aircraft back to its initial configuration.
(1) In the cockpit, on the OXYGEN section of the overhead control and indicating panel 21VU, release the OXYGEN/CREW SUPPLY pushbutton switch (the OFF legend comes on).
(2) De-energize the aircraft electrical circuits
(Ref. AMM TASK 24-41-00-862-002).
(3) Make sure that the work area is clean and clear of tools and other items.
(4) Fully open the valve of the oxygen storage cylinder.
(5) Remove the WARNING NOTICE(S).
(6) Close the access door 812.
(7) Remove the access platform(s).
(8) Make an entry in the logbook.
Subtask 35-10-00-860-062-B ** ON A/C NOT FOR ALL (1) In the cockpit, on the OXYGEN section of the overhead control and indicating panel 21VU, release the OXYGEN/CREW SUPPLY pushbutton switch (the OFF legend comes on).
(2) De-energize the aircraft electrical circuits
(Ref. AMM TASK 24-41-00-862-002).
(3) Make sure that the work area is clean and clear of tools and other items.
(4) Fully open the valve of the oxygen storage cylinder.
(5) Remove the WARNING NOTICE(S).
(6) Close the access door 812.
(7) Remove the access platform(s).
(8) Make an entry in the logbook.
A. Put the aircraft back to its initial configuration.
(1) In the cockpit, on the OXYGEN section of the overhead control and indicating panel 21VU, make sure that the CREW SUPPLY pushbutton switch is released (the OFF legend is on).
(2) De-energize the aircraft electrical circuits
(Ref. AMM TASK 24-41-00-862-002).
(3) Make sure that the work area is clean and clear of tools and other items.
(4) Turn the manual shutoff valves
(b) Turn the manual shutoff valve (4) of the crew oxygen-storage cylinder 5750HM2 (3) very slowly until it is fully open.
(5) Remove the WARNING NOTICE(S).
(6) Close access door 812 (Ref. AMM TASK 52-41-00-410-002).
(7) Remove the access platform(s).
(8) Make an entry in the logbook.
(1) In the cockpit, on the OXYGEN section of the overhead control and indicating panel 21VU, make sure that the CREW SUPPLY pushbutton switch is released (the OFF legend is on).
(2) De-energize the aircraft electrical circuits
(Ref. AMM TASK 24-41-00-862-002).
(3) Make sure that the work area is clean and clear of tools and other items.
(4) Turn the manual shutoff valves
CAUTION:
TURN THE MANUAL SHUTOFF VALVES VERY SLOWLY ON ALL THE CREW OXYGEN-STORAGE CYLINDERS UNTIL THEY ARE FULLY OPEN. IF YOU TURN THE MANUAL SHUTOFF VALVES TOO QUICKLY, YOU CAN CAUSE DAMAGE TO THE EQUIPMENT.
CAUTION:
TURN THE HANDVALVES ON ALL OXYGEN BOTTLES UNTIL THEY ARE FULLY OPEN. IF THE HANDVALVES ARE NOT FULLY OPEN BEFORE FLIGHT, IT IS POSSIBLE THAT THE OXYGEN PRESSURE DATA ON THE ECAM DOOR/OXY PAGE WILL NOT BE CORRECT.
(a) Turn the manual shutoff valve (2) of the crew oxygen-storage cylinder 5750HM1 (1) very slowly until it is fully open. (b) Turn the manual shutoff valve (4) of the crew oxygen-storage cylinder 5750HM2 (3) very slowly until it is fully open.
(5) Remove the WARNING NOTICE(S).
(6) Close access door 812 (Ref. AMM TASK 52-41-00-410-002).
(7) Remove the access platform(s).
(8) Make an entry in the logbook.