DOC AIRBUS | AMM A320FLeakage Test of the LP Oxygen System for the Crew with the VARIAN HELITEST TOOL
TASK 35-10-00-790-002-A
Leakage Test of the LP Oxygen System for the Crew with the VARIAN HELITEST TOOL
A. Fixtures, Tools, Test and Support Equipment
B. Work Zones and Access Panels
C. Referenced Information
3. Job Set-up
Subtask 35-10-00-010-057-A
Subtask 35-10-00-790-052-A
Subtask 35-10-00-860-056-A
[Rev.10 from 2021]
2026.04.01 01:03:50 UTC
Leakage Test of the LP Oxygen System for the Crew with the VARIAN HELITEST TOOL
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:
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.
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.
1. Reason for the JobNOTE: Make sure that you do the leakage test of the LP oxygen system for the crew with the oxygen cylinder source before you do this procedure.
2. Job Set-up InformationA. Fixtures, Tools, Test and Support Equipment
| REFERENCE | QTY | DESIGNATION |
|---|---|---|
| No specific | AR | ACCESS PLATFORM 2M (6 FT) |
| No specific | AR | WARNING NOTICE(S) |
| 969-4000 | 1 | HELITEST-AERO KIT |
| 969-4200 | 1 | TOOLING KIT-OXYGEN |
| DET0X4200 | 1 | HELITEST AERO KIT |
| ZONE/ACCESS | ZONE DESCRIPTION |
|---|---|
| 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 31-60-00-860-001-A | EIS Start Procedure |
| TASK 31-60-00-860-002-A | EIS Stop Procedure |
| TASK 35-00-00-860-001-A | Special Precautions When Working on a Gaseous Oxygen System |
| TASK 35-11-41-000-001-A | Removal of the Crew Oxygen-Storage Cylinder |
| TASK 35-11-41-400-001-A | Installation of the Crew Oxygen-Storage Cylinder |
Flight-Crew Oxygen System - SchematicSubtask 35-10-00-010-057-A
A. Get access to the avionics compartment.
(1) Put an ACCESS PLATFORM 2M (6 FT) in position at access door 812.
(2) Open access door 812.
(3) In the avionics compartment, open the cover of the oxygen compartment.
Subtask 35-10-00-860-055-A (1) Put an ACCESS PLATFORM 2M (6 FT) in position at access door 812.
(2) Open access door 812.
(3) In the avionics compartment, open the cover of the oxygen compartment.
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) Do the EIS start procedure (upper ECAM DU and lower ECAM DU only)
(Ref. AMM TASK 31-60-00-860-001).
(4) Make sure that the avionics compartment and the cockpit have a good airflow.
(5) Fully close the valve of the oxygen storage cylinder (5750HM).
(6) Put a WARNING NOTICE(S) in position to tell persons not to open the valve of the oxygen storage cylinder.
Subtask 35-10-00-865-052-A (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) Do the EIS start procedure (upper ECAM DU and lower ECAM DU only)
(Ref. AMM TASK 31-60-00-860-001).
(4) Make sure that the avionics compartment and the cockpit have a good airflow.
(5) Fully close the valve of the oxygen storage cylinder (5750HM).
(6) Put a WARNING NOTICE(S) in position to tell persons not to open the valve of the oxygen storage cylinder.
C. Make sure that this(these) circuit breaker(s) is(are) closed:
Subtask 35-10-00-860-058-A | PANEL | DESIGNATION | FIN | LOCATION |
|---|---|---|---|
| ** ON A/C ALL | |||
| 49VU | OXYGEN/CREW/OXY/SPLY | 1HT | HA01 |
D. Preparation for Installation
(1) Bleeding of 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.
(2) Preparation before the test
(a) Remove the oxygen storage cylinder (Ref. AMM TASK 35-11-41-000-001).
(b) Install and connect the 969-4000 HELITEST-AERO KIT and 969-4200 TOOLING KIT-OXYGEN or the DET0X4200 HELITEST AERO KIT at the position of the oxygen storage cylinder.
The tool cylinder contains a gaseous mixture of ten percent helium and ninety percent nitrogen at a pressure of 127 bar (1841.98 psi).
4. Procedure(1) Bleeding of 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.
(2) Preparation before the test
(a) Remove the oxygen storage cylinder (Ref. AMM TASK 35-11-41-000-001).
(b) Install and connect the 969-4000 HELITEST-AERO KIT and 969-4200 TOOLING KIT-OXYGEN or the DET0X4200 HELITEST AERO KIT at the position of the oxygen storage cylinder.
The tool cylinder contains a gaseous mixture of ten percent helium and ninety percent nitrogen at a pressure of 127 bar (1841.98 psi).
Subtask 35-10-00-790-052-A
A. Test
(2) Calibrate the HELITEST in PPM.
(3) Measure the leaks and compare the values with those in the table that follows:
(4) If the values are more than the permitted limits, replace the defective equipment.
5. Close-upNOTE: Before you do this test, you must read carefully the instructions to use the test equipment and the position of the different equipment.
You must also know the maximum permitted leakage values.
You must do this test immediately after the initial gaseous-mixture pressurization of the system with the tool cylinder.
If not, there can be too much helium in the avionics compartment and the measurement of the leaks will be incorrect.
(1) Open the valve of the tool cylinder. You must also know the maximum permitted leakage values.
You must do this test immediately after the initial gaseous-mixture pressurization of the system with the tool cylinder.
If not, there can be too much helium in the avionics compartment and the measurement of the leaks will be incorrect.
(2) Calibrate the HELITEST in PPM.
(3) Measure the leaks and compare the values with those in the table that follows:
| EQUIPMENT | Maximum Leak permitted with a Mixture of 10% Helium "PPM" |
|---|---|
| Coupling | 50 |
| Low-Pressure Solenoid Valve | 300 |
| Pressure Regulator/Transmitter | 300 |
| Low-Pressure Flexible Hose | 100 |
| Mask Stowage Box (Box closed) | 500 |
Subtask 35-10-00-860-056-A
A. Bleeding of the Gaseous Mixture from the Oxygen System
(1) Close the valve of the tool cylinder.
(2) On the 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.
(3) Release the PRESS TO TEST AND RESET control lever.
(4) Release the PRESS TO TEST/EMERGENCY knob.
(5) 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.
(6) Do this bleeding procedure for all of the oxygen-mask stowage boxes.
Subtask 35-10-00-860-057-A (1) Close the valve of the tool cylinder.
(2) On the 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.
(3) Release the PRESS TO TEST AND RESET control lever.
(4) Release the PRESS TO TEST/EMERGENCY knob.
(5) 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.
(6) Do this bleeding procedure for all of the oxygen-mask stowage boxes.
B. Put the aircraft back to its initial configuration.
(1) Disconnect the tool cylinder.
(2) Install the oxygen storage cylinder (Ref. AMM TASK 35-11-41-400-001).
(3) Fully open the valve of the oxygen storage cylinder.
(4) In the cockpit, on the OXYGEN section of the overhead control and indicating panel 21VU, make sure that the CREW SUPPLY pushbutton switch is pushed (OFF legend off).
(5) Bleed the oxygen system:
(a) On the oxygen-mask stowage box, push and hold the PRESS TO TEST AND RESET control lever.
At the same time, on the mask regulator, push and hold the PRESS TO TEST/EMERGENCY knob.
(b) Release the PRESS TO TEST AND RESET control lever.
(c) Release the PRESS TO TEST/EMERGENCY knob.
(d) 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.
(6) Do this bleeding procedure for all of the oxygen-mask stowage boxes.
(7) 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).
(8) Do the EIS stop procedure (Upper ECAM DU and lower ECAM DU only) (Ref. AMM TASK 31-60-00-860-002).
(9) De-energize the aircraft electrical circuits
(Ref. AMM TASK 24-41-00-862-002).
(10) Make sure that the work area is clean and clear of tools and other items.
Subtask 35-10-00-410-056-A (1) Disconnect the tool cylinder.
(2) Install the oxygen storage cylinder (Ref. AMM TASK 35-11-41-400-001).
(3) Fully open the valve of the oxygen storage cylinder.
(4) In the cockpit, on the OXYGEN section of the overhead control and indicating panel 21VU, make sure that the CREW SUPPLY pushbutton switch is pushed (OFF legend off).
(5) Bleed the oxygen system:
(a) On the oxygen-mask stowage box, push and hold the PRESS TO TEST AND RESET control lever.
At the same time, on the mask regulator, push and hold the PRESS TO TEST/EMERGENCY knob.
(b) Release the PRESS TO TEST AND RESET control lever.
(c) Release the PRESS TO TEST/EMERGENCY knob.
(d) 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.
(6) Do this bleeding procedure for all of the oxygen-mask stowage boxes.
(7) 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).
(8) Do the EIS stop procedure (Upper ECAM DU and lower ECAM DU only) (Ref. AMM TASK 31-60-00-860-002).
(9) De-energize the aircraft electrical circuits
(Ref. AMM TASK 24-41-00-862-002).
(10) Make sure that the work area is clean and clear of tools and other items.
C. Close Access
(1) Close the cover of the oxygen compartment.
(2) Remove the WARNING NOTICE(S).
(3) Close access door 812.
(4) Remove the access platform(s).
(1) Close the cover of the oxygen compartment.
(2) Remove the WARNING NOTICE(S).
(3) Close access door 812.
(4) Remove the access platform(s).