# Airbus All Operators Transmission A35N017-22 Copy: Revision 2 ("AOT A35N017-22 R2"), 6 pages: PDF https://openairdocs.org/files/sha256/c0/01/c001dcb58089530327da0eac01b178afc560fdec61cf73fed34cc41249cf372b; text https://openairdocs.org/service-documents/airbus/aot-a35n017-22/file/c001dcb58089.md. Rights: © Airbus S.A.S. Filed by the FAA in regulations.gov docket FAA-2023-1994, the docket of AD 2023-25-09. Not covered by OpenAirDocs’ CC0 dedication. ## Details - Manufacturer: [Airbus](https://openairdocs.org/service-documents/airbus.md) - Type: Other document (All Operators Transmission) - Number: A35N017-22 - Latest revision known: A35N017-22, Revision 2, dated February 14, 2023 (OpenAirDocs) - Page: https://openairdocs.org/service-documents/airbus/aot-a35n017-22 ## Text (6 pages) Rights: © Airbus S.A.S. Filed by the FAA in regulations.gov docket FAA-2023-1994, the docket of AD 2023-25-09. Not covered by OpenAirDocs’ CC0 dedication. Each page's text from the PDF; open the PDF at a page with #page=N. ### Page 1 CUSTOMER SERVICES DIRECTORATE 2 ROND POINT EMILE DEWOITINE 31700 BLAGNAC FRANCE TELEPHONE + 33 (0)5 61 93 33 33 ALERT OPERATORS TRANSMISSION - AOT AOT ref: A35N017-22 Rev 02 Page 1 of 6 Date: 14-FEB-2023 C80_AOT_FM1104649_v8.0 © AIRBUS S.A.S. 2023. ALL RIGHTS RESERVED. CONFIDENTIAL AND PROPRIETARY DOCUMENT SUBJECT: ATA 35 – SafeLAV Gaseous Oxygen Container replacement AIRCRAFT TYPE: A318, A319, A320, A321 OUR REF.: A35N017-22 Rev 02 dated 14-FEB-2023 OUR PREVIOUS REF. 1: A35N017-22 Rev 01 dated 19-JAN-2023 OUR PREVIOUS REF. 2: A35N017-22 Rev 00 dated 29-NOV-2022 EFFECTIVITY DATE: 13th December 2022 0. REASON FOR REVISION The reason for this AOT revision is to add 3 missing Part Numbers 22G150150640400, 22G220150020400 and 22G220150320400 in paragraphs 3.1 and 5. and to add References 4 and 5 and associated information to support this AOT implementation. These Part Numbers were already included in VSIL Ref. 3. Accordingly additional work is not expected to be required if the AOT instructions have been completed with previous Revision 01. The revised paragraphs are indicated between ***BEG. REV*** and ***END REV***. 1. AIRCRAFT AFFECTED ***BEG. REV*** All A320 family aircraft, with Lavatories equipped with unregulated decentralized gaseous oxygen containers (SafeLAV) having Part Numbers and Serial Numbers as provided in Reference 3. ***END REV*** 2. REFERENCED DOCUMENTATION 2.1 APPENDIX None 2.2 REFERENCES Reference 1: A320 AMM TASK 35-21-41-000-001-A – “Removal of the Emergency Oxygen Containers” Reference 2: A320 AMM TASK 35-21-41-400-001-A – “Installation of the Emergency Oxygen Containers” Reference 3: COLLINS Aerospace VSIL Ref: D1379-35-070 Revision 01 dated Dec 07/2022 or later revision if applicable. ***BEG. REV*** Reference 4: Airbus Retrofit Information Letter (RIL) Ref. X35M22002603 Reference 5: Airbus In-Service Information (ISI) article Ref. 35.21.00013 ***END REV*** ### Page 2 ALERT OPERATORS TRANSMISSION - AOT AOT ref: A35N017-22 Rev 02 Page 2 of 6 Date: 14-FEB-2023 C80_AOT_FM1104649_v8.0 © AIRBUS S.A.S. 2023. ALL RIGHTS RESERVED. CONFIDENTIAL AND PROPRIETARY DOCUMENT 3. REASON The purpose of this AOT is to advise A320 family operators about a quality escape on a component of some oxygen containers and to request the replacement of the affected oxygen containers in operation and in airline spare stock. 3.1 FACTS Airbus informs the operators that a quality escape on decentralized unregulated gaseous oxygen actuators could lead to no oxygen availability when needed on both masks of the SafeLAV gaseous oxygen containers. ***BEG. REV*** The list of potentially affected SafeLAV gaseous oxygen containers part numbers are: 22G150150320400, 22G150150460400, 22G150150640400, 22G150150700400, 22G150150920400, 22G220150020400, 22G220150320400, 22G220150460400 and 22G220150700400. ***END REV*** 3.2 HISTORY/BACKGROUND Four instances of failure to activate of a decentralized unregulated gaseous oxygen actuator have been reported during production testing of new manufactured oxygen containers. 3.3 ROOT CAUSE The root cause is the missing heat treatment of the oxygen actuator assembly actuation pin of the SafeLAV gaseous oxygen container. It causes a jam of the pin and its absence of movement leads to oxygen actuator failure to activate, with no oxygen supply flow. 3.4 INVESTIGATION The investigation shows that one heat treatment batch of actuation pins had untreated and treated pins mixed at the pin supplier. Approximately 40 affected pins without heat treatment have been mixed and randomly used for the oxygen actuators assembly of a production batch of SafeLAV gaseous oxygen containers. 3.5 CONSEQUENCES There is no procedure nor pre-flight check that would allow to identify this malfunction, it is only identifiable at oxygen container activation. The failure is considered as a dormant failure affecting approximately 40 units within the suspect batch of SafeLAV gaseous oxygen containers. Containment action in production to quarantine part of the suspect batch has been performed. There is a risk of no oxygen supply on both masks of the Lavatory in case of activation of an affected oxygen container during a cabin severe decompression event. 4. OBJECTIVES OF THIS AOT This AOT requires a replacement and return to the manufacturer of all potentially affected oxygen containers installed on airline aircraft and in airline spare stock as described in Reference 3. ### Page 3 ALERT OPERATORS TRANSMISSION - AOT AOT ref: A35N017-22 Rev 02 Page 3 of 6 Date: 14-FEB-2023 C80_AOT_FM1104649_v8.0 © AIRBUS S.A.S. 2023. ALL RIGHTS RESERVED. CONFIDENTIAL AND PROPRIETARY DOCUMENT 5. MAINTENANCE PROCEDURE ***BEG REV*** Oxygen containers to be replaced are all SafeLAV gaseous oxygen containers having a Part Number 22G150150320400, 22G150150460400, 22G150150640400, 22G150150700400, 22G150150920400, 22G220150020400, 22G220150320400, 22G220150460400 or 22G220150700400 with a Serial Number as listed in the Reference 3, and in each of the following situations: -Oxygen container is installed on aircraft -Oxygen container is in airline spare stock ***END REV*** NOTE: This AOT is classified mandatory or expected to be classified mandatory by an Airworthiness Directive (AD). If the instructions of this AOT are marked as Required for Compliance (RC), the operator must follow the instructions as indicated. These instructions are introduced by “in accordance with”. NOTE: The instructions of this AOT include procedures given in other documents or in other sections of the AOT. If the instructions of this AOT are NOT marked as Required for Compliance (RC), the operator can use an alternative procedure accepted by his/her local authority. These instructions are introduced by “refer to”. NOTE: When this AOT gives the access or close-up instructions with no return to service tests, the operator can adapt these instructions to add flexibility to the maintenance operations. The technical intent of this AOT must comply with the set parameters. 5.1 PLANNING – (RC) Perform the replacement of all oxygen containers referenced in Reference 3 at next convenient opportunity, but no later than 8 months from AOT effectivity date. 5.2 MANPOWER The estimated time to perform this replacement is 1,25 MH per oxygen container (0,5 for Removal + 0,75 for Installation). 5.3 ACCESS 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. WARNING: KEEP ALL HYDROCARBONS (FUELS, LUBRICANTS, ETC.) AWAY FROM ALL SOURCE OF OXYGEN. OXYGEN BECOMES EXPLOSIVE WHEN IT TOUCHES HYDROCARBONS. WARNING: ### Page 4 ALERT OPERATORS TRANSMISSION - AOT AOT ref: A35N017-22 Rev 02 Page 4 of 6 Date: 14-FEB-2023 C80_AOT_FM1104649_v8.0 © AIRBUS S.A.S. 2023. ALL RIGHTS RESERVED. CONFIDENTIAL AND PROPRIETARY DOCUMENT CLEAN THE TOOLS AND MAKE SURE YOUR HANDS ARE CLEAN TO PREVENT CONTAMINATION OF THE OXYGEN SYSTEM. WARNING: 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. CAUTION: BEFORE YOU MOVE AN OXYGEN GENERATOR (WITH OR WITHOUT AN OXYGEN CONTAINER), INSTALL A SAFETY RING OR PIN AND WARNING FLAG ON ITS IGNITION ACTUATOR. YOU MUST DO THIS: - BEFORE YOU MOVE IT TO A DIFFERENT LOCATION - BEFORE YOU PUT IT INTO STORAGE - BEFORE YOU PREPARE IT FOR TRANSPORT. BEFORE YOU CLOSE THE DOOR OF THE OXYGEN CONTAINER, ATTACH ONE END OF THE WARNING FLAG TO THE DOOR'S OUTER SURFACE. IF THE SAFETY RING OR PIN AND WARNING FLAG IS NOT CORRECTLY INSTALLED, THE OXYGEN GENERATOR CAN START ACCIDENTALLY AND CAUSE DAMAGE. For oxygen containers installed on aircraft, access to the container is obtained inside corresponding Lavatory by removing the emergency oxygen container cover panel, through section “3. Job Set-up” in Reference 1. 5.4 INSPECTION – (RC) All A320 family operators are required to identify the affected oxygen containers in accordance with Reference 3 and: -utilizing applicable records, OR -by visual inspection of the oxygen container on aircraft or on the shelf stock directly. 5.5 FINDINGS – (RC) The identified affected oxygen containers have to be replaced on aircraft with an unaffected part or removed from stock. 5.6 INSTRUCTIONS – (RC) CAUTION: MAKE SURE THAT YOU SUPPORT THE EMERGENCY OXYGEN CONTAINER WHEN YOU LOWER IT. IF IT FALLS, DAMAGE CAN OCCUR TO THE CONTAINER AND TO THE ADJACENT EQUIPMENT. CAUTION: MAKE SURE THAT THE ELECTRICAL CONNECTORS ARE CLEAN BEFORE YOU DISCONNECT OR CONNECT THEM. CONTAMINATION ON THE ELECTRICAL CONNECTORS CAN CAUSE DAMAGE TO EQUIPMENT. CAUTION: ### Page 5 ALERT OPERATORS TRANSMISSION - AOT AOT ref: A35N017-22 Rev 02 Page 5 of 6 Date: 14-FEB-2023 C80_AOT_FM1104649_v8.0 © AIRBUS S.A.S. 2023. ALL RIGHTS RESERVED. CONFIDENTIAL AND PROPRIETARY DOCUMENT MAKE MATCH MARKS ON ALL THE ELECTRICAL WIRES BEFORE YOU DISCONNECT THEM. INCORRECT CONNECTION OF WIRES WILL CAUSE DAMAGE TO EQUIPMENT. Remove and replace the affected oxygen container installed on aircraft in accordance with Reference 1 starting from section “4. Procedure” and in accordance with Reference 2 until section “5. Close-up”. WARNING: AFTER YOU INSTALL THE GENERATORS IN THE EMERGENCY OXYGEN CONTAINERS, REMOVE THE SAFETY RINGS OR SAFETY PINS FROM THE GENERATORS. IF YOU DO NOT REMOVE THEM, THE GENERATORS WILL NOT OPERATE. CAUTION: DO NOT USE TOO MUCH FORCE TO CLOSE THE EMERGENCY OXYGEN CONTAINER. IF YOU USE TOO MUCH FORCE, YOU CAN CAUSE DAMAGE TO THE LATCH MECHANISM. IF THE LATCH MECHANISM DOES NOT ENGAGE EASILY, MAKE SURE THAT THE EQUIPMENT IN THE EMERGENCY OXYGEN CONTAINER IS CORRECTLY INSTALLED. CAUTION: REFER TO THE MATCH MARKS MADE DURING THE REMOVAL WHEN YOU CONNECT THE ELECTRICAL WIRES. INCORRECT CONNECTION OF THE WIRES WILL CAUSE DAMAGE TO EQUIPMENT. ***BEG REV*** Once replaced with an unaffected container in accordance with Reference 3, report to Airbus as per Reference 4 and return the affected oxygen container removed from aircraft or from stock to Collins Aerospace as per Reference 3 and Reference 4. ***END REV*** The operators shall verify that any oxygen containers installed on aircraft in the future are not part of the affected parts in accordance with Reference 3, until all the affected parts are identified and returned. 5.7 SPARES AND TOOLING Replacement of the oxygen container installed on aircraft, refer to Reference 1 and Reference 2, requires: -CAP - BLANKING -ELEC CONTACTS INSERTION EXTRACTION TOOL M15570-20 -SAFETY CLIP - CIRCUIT BREAKER -STEPLADDER 1.0 M (3.3 FT) -WARNING NOTICE(S) -98A25207503000 PULLEY ASSEMBLY - SEALING CORD -TOOL-MANUAL RELEASE ***BEG REV*** The oxygen container of the same Part Number has to be ordered to Collins Aerospace as per Reference 3 and Reference 4. ***END REV*** 6. ADDITIONAL INFORMATION 6.1 FOLLOW-UP PLAN ### Page 6 ALERT OPERATORS TRANSMISSION - AOT AOT ref: A35N017-22 Rev 02 Page 6 of 6 Date: 14-FEB-2023 C80_AOT_FM1104649_v8.0 © AIRBUS S.A.S. 2023. ALL RIGHTS RESERVED. CONFIDENTIAL AND PROPRIETARY DOCUMENT ***BEG REV*** Additional information about this AOT is available in Reference 5. ***END REV*** 6.2 IMPACTED DOCUMENTATION N/A 7. AOT APPROVAL The technical content of this document is approved under the authority of the DOA ref.EASA.21J.031. 8. REPORTING ***BEG REV*** This AOT is the subject of an Airbus monitored retrofit campaign as described in Reference 4. ***END REV*** In both cases (with or without findings), address your inspection results to Airbus Monitored Retrofit through the e-mail address: monitored.retrofit@airbus.com. Give the AOT reference in the mail title, as follows: {A35N017-22} Inspection Result You can address your questions about this AOT to Airbus Customer Services through TechRequest on Airbus World, selecting Engineering Domain, Engineering Support Section and ATA 35-20/Topic SafeLAV Gaseous Oxygen Container replacement. Best Regards, Wolfgang WOHLERS HEAD OF ENGINEERING & MAINTENANCE CUSTOMER SERVICES Jean-Pierre GOMEZ VICE PRESIDENT A320 PROGRAMME CUSTOMER SERVICES --- OpenAirDocs.org is an independent research project of [Contrail Labs](https://contraillabs.com/). It is not affiliated with the FAA or the NTSB. Source documents are U.S. government works in the public domain, except the copies of manufacturers’ service documents, which belong to their rights holders.