# Airbus All Operators Transmission A71P016-19 Copy: No revision named ("AOT A71P016-19"), 16 pages: PDF https://openairdocs.org/files/sha256/be/29/be29a9dab89004a0270a9f17c1dd17b46aa297019d8d2739a680ab6c532f8ebf; text https://openairdocs.org/service-documents/airbus/aot-a71p016-19/file/be29a9dab890.md. Rights: © Airbus S.A.S. Filed by the FAA in regulations.gov docket FAA-2019-0606, the docket of AD 2019-16-03. Not covered by OpenAirDocs’ CC0 dedication. ## Details - Manufacturer: [Airbus](https://openairdocs.org/service-documents/airbus.md) - Type: Other document (All Operators Transmission) - Number: A71P016-19 - Page: https://openairdocs.org/service-documents/airbus/aot-a71p016-19 ## Text (16 pages) Rights: © Airbus S.A.S. Filed by the FAA in regulations.gov docket FAA-2019-0606, the docket of AD 2019-16-03. 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: A71P016-19 Rev 00 Page 1 of 16 Date: 15-JUL-2019 © AIRBUS S.A.S. 2019. ALL RIGHTS RESERVED. CONFIDENTIAL AND PROPRIETARY DOCUMENT SUBJECT: ATA 71 – TRENT XWB-75 / -84 / -97 - ENGINE MOUNTS AND THRUST LINKS WASHERS AIRCRAFT TYPE: A350 OUR REF.: A71P016-19 Rev 00 dated 15-JUL-2019 1. AIRCRAFT AFFECTED A350-900 Operator MSN AAR 0094, 0117, 0144, 0176, 0198, 0218, 0224, 0234, 0301 CAL 0049, 0057, 0066, 0073, 0092, 0105, 0121, 0138, 0151, 0162, 0179, 0191, 0208, 0239 CCA 0167, 0178, 0217, 0231, 0240, 0247, 0268, 0284, 0295, 0311 CES 0248, 0261, 0269, 0272, 0291, 0307 CHH 0098, 0112, 0226, 0245 CPA 0029, 0032, 0034, 0038, 0039, 0046, 0053, 0058, 0061, 0070, 0072, 0075, 0085, 0093, 0101, 0109, 0119, 0128, 0137, 0148, 0154, 0155 CRK 0124, 0153, 0168, 0187, 0235, 0256 CSC 0052, 0055, 0060, 0281 CSN 0318 DAL 0115, 0135, 0149, 0160, 0164, 0175, 0182, 0190, 0199, 0204, 0210, 0267, 0277 DLH 0074, 0080, 0087, 0127, 0136, 0146, 0174, 0184, 0202, 0209, 0212, 0255, 0287, 0292, ETH 0040, 0043, 0089, 0103, 0120, 0147, 0180, 0196, 0205, 0259, 0289, 0310 EVE 0293 FBU 0005, 0193, 0325 FIN 0018, 0019, 0020, 0022, 0023, 0028, 0051, 0097, 0104, 0113, 0134, 0264, 0273, 0300, FWI 0082, 0091 HVN 0014, 0015, 0016, 0017, 0056, 0067, 0086, 0129, 0150, 0173, 0192, 0197, 0279, 0297 IBE 0219, 0227, 0271, 0302, 0312 JAL 0321 MAS 0159, 0165, 0183, 0195, 0203, 0213 MAU 0145, 0157 PAL 0221, 0228, 0236, 0243, 0280, 0303 QTR 0006, 0007, 0008, 0009, 0010, 0011, 0012, 0013, 0021, 0025, 0033, 0036, 0042, 0047, 0063, 0064, 0069, 0076, 0078, 0079, 0083, 0090, 0100, 0106, 0114, 0126, 0132, 0143, 0163, 0172, 0207, 0211, 0214, 0237, 0249, 0265 ### Page 2 ALERT OPERATORS TRANSMISSION - AOT AOT ref: A71P016-19 Rev 00 Page 2 of 16 Date: 15-JUL-2019 © AIRBUS S.A.S. 2019. ALL RIGHTS RESERVED. CONFIDENTIAL AND PROPRIETARY DOCUMENT SIA 0026, 0030, 0031, 0037, 0041, 0054, 0062, 0068, 0077, 0081, 0084, 0096, 0099, 0107, 0116, 0122, 0133, 0140, 0158, 0170, 0186, 0216, 0220, 0223, 0230, 0232, 0238, 0244, 0254, 0263, 0276, 0278, 0294, 0305, 0309, 0316, 0322 TAM 0024, 0027, 0035, 0045, 0048, 0200, 0250 THA 0044, 0050, 0095, 0111, 0123, 0130, 0142, 0177, 0181, 0185, 0189, 0201 A350-1000 Operator MSN CPA 0118, 0169, 0188, 0206, 0225, 0233, 0252,0258, 0262, 0286, 0296 and 0306 QTR 0088, 0102, 0110, 00125, 0141, 0161, 0215,0229 and 0241 ETD 0290 2. REFERENCED DOCUMENTATION 2.1 APPENDIX 2.2 REFERENCES Ref 1: A71P015-19 Rev 00 dated 08-JUL-2019 Ref 2: TASK A350-A-71-13-XX-00001-398A-A Opening of the Fan Cowl Doors with the Power Door Opening System (PDOS) Ref 3: TASK A350-A-71-13-XX-02001-398A-A Manual Opening of the Fan Cowl Doors Ref 4: TASK A350-A-78-3X-XX-00001-343A-A Thrust Reverser (T/R) Inhibition Procedure Ref 5: TASK A350-A-78-3X-XX-00001-398A-A Opening of the Thrust Reverser (T/R) Cowls with the Power Door Opening System (PDOS) Ref 6: TASK A350-A-71-13-XX-01001-398A-A Closing of the Fan Cowl Doors with the Power Door Opening System (PDOS) Ref 7: TASK A350-A-71-13-XX-03001-398A-A Manual Closing of the Fan Cowl Doors Ref 8: TASK A350-A-78-3X-XX-01001-398A-A Closing of the Thrust Reverser (T/R) Cowls with the Power Door Opening System (PDOS) Ref 9: TASK A350-A-78-3X-XX-01001-343A-A Thrust Reverser (T/R) Disinhibition Procedure 3. REASON 3.1 FACTS An A350-1000 in-service engine has been found with a front engine mount pin having moved axially out of place. Investigations have revealed that incorrect washers P/N KH52819 were installed on the LH and RH pins of this engine mount. The correct washers to be installed on the front engine mount is P/N FK30900 (bigger). The washers P/N KH52819 (smaller) are normally to be installed on the thrust links. Subsequently AOT Ref 1 has been issued to provide A350-1000 operators with instructions to check the washers installed on the front engine mount pins primary locations. ### Page 3 ALERT OPERATORS TRANSMISSION - AOT AOT ref: A71P016-19 Rev 00 Page 3 of 16 Date: 15-JUL-2019 © AIRBUS S.A.S. 2019. ALL RIGHTS RESERVED. CONFIDENTIAL AND PROPRIETARY DOCUMENT 3.2 CONSEQUENCES There are 2 washers per pin on the Front Engine Mount: Figure 1: Front Engine Mount Pin Assembly With the incorrect washers installed (with an outer diameter smaller than the pin diameter), the pins can move axially and potentially become completely disengaged. The engine mount assembly has a fail-safe design: Loads are carried by two links (Left and Right positions) and, in case of failure, a third “fail-safe” link pin (centre position) is activated and takes the loads. In the worst-case scenario, full disengagement of one of the pins could lead to activation of the fail- safe load path. 3.3 AIM Based on the conclusion of the investigation, the operators are requested to inspect the A350 fleet, to ensure that the correct engine mount washer kits are installed on: o The Trent XWB-75 and -84 front engine mount primary pins o The Trent XWB-75 / -84 / -97 rear engine mount primary pins and thrust links pins 4. SHORT TERM ACTION 4.1 PLANNING AND MANPOWER 4.1.1 ACCOMPLISHMENT TIMESCALE The instructions provided in this AOT have to be performed before 31-AUG-2019 or before next flight, whichever comes latest. 4.2 DESCRIPTION 4.2.1 ACCESS ### Page 4 ALERT OPERATORS TRANSMISSION - AOT AOT ref: A71P016-19 Rev 00 Page 4 of 16 Date: 15-JUL-2019 © AIRBUS S.A.S. 2019. ALL RIGHTS RESERVED. CONFIDENTIAL AND PROPRIETARY DOCUMENT In order to access to the Front Engine Mount area: - The Fan Cowls have to be opened as per Ref 2 or Ref 3 In order to access the Rear Engine Mount and Thrust Links area: - The Thrust Reverser has to be inhibited as per Ref 4 - The Fan Cowls have to be opened as per Ref 2 or Ref 3 - The Thrust Reverser Cowls have to be opened as per Ref 5 4.2.2 INSPECTION REQUIREMENTS The purpose of this inspection is to confirm that the correct washers are installed. Additional check or reporting regarding the condition of the parts is not required. This should be managed separately, in accordance with the relevant MPD tasks. In locations where visual access to the Part Number (P/N) of the washers is restricted, it is possible to use a camera or borescope to take a picture of the washers and then read the P/N from the picture. 1) TRENT XWB-75 / -84 Inspection On Engine 1 and Engine 2, perform a visual inspection of the primary pins washers: A) Front Mount Washers Visual inspection to confirm that all 8 primary pins washers installed on the front mount are: - The correct P/N FK30900, or - That the assembly visually corresponds to the correct picture, or - That the washers outer diameter measures 47,0 – 49,0 mm ### Page 5 ALERT OPERATORS TRANSMISSION - AOT AOT ref: A71P016-19 Rev 00 Page 5 of 16 Date: 15-JUL-2019 © AIRBUS S.A.S. 2019. ALL RIGHTS RESERVED. CONFIDENTIAL AND PROPRIETARY DOCUMENT Figure 2: Washers (8) to be inspected on Front Engine Mount Figure 3: Incorrect Installation (washer Outer Diameter is smaller than bushing Inner Diameter) Bushing is visible around the washer ### Page 6 ALERT OPERATORS TRANSMISSION - AOT AOT ref: A71P016-19 Rev 00 Page 6 of 16 Date: 15-JUL-2019 © AIRBUS S.A.S. 2019. ALL RIGHTS RESERVED. CONFIDENTIAL AND PROPRIETARY DOCUMENT Figure 4: P/N FK30900 Correct Installation (washer Outer Diameter is larger than bushing Inner Diameter) Bushing is not visible around the washer ### Page 7 ALERT OPERATORS TRANSMISSION - AOT AOT ref: A71P016-19 Rev 00 Page 7 of 16 Date: 15-JUL-2019 © AIRBUS S.A.S. 2019. ALL RIGHTS RESERVED. CONFIDENTIAL AND PROPRIETARY DOCUMENT B) Thrust Links Washers Visual inspection to confirm that all 4 washers installed on the thrust link are: - The correct P/N FK30900, or - That the assembly visually corresponds to the correct picture, or - That the washers outer diameter measures 47,0 – 49,0 mm Figure 5: Washers (4) to be inspected on Thrust Links ### Page 8 ALERT OPERATORS TRANSMISSION - AOT AOT ref: A71P016-19 Rev 00 Page 8 of 16 Date: 15-JUL-2019 © AIRBUS S.A.S. 2019. ALL RIGHTS RESERVED. CONFIDENTIAL AND PROPRIETARY DOCUMENT C) Rear Mount Washers Visual inspection to confirm that all primary pins washers installed on the rear mount are: - The correct P/N (depending on the particular configuration, as per below details), or - That the visual inspection corresponds to the correct picture or - That the washer outer diameter measures are within the range specified for each configuration, as detailed below: PART 1 - Refer to Figures 6 & 7 Pre SB 71-J014 Correct P/N KH17548 Washers outer diameter measures 67,0 – 69,0 mm Post SB 71-J014 Correct P/N KH34697 Washers outer diameter measures 62,9 – 64,9 mm Figure 6: Washers (12) to be inspected on the Rear Mount ### Page 9 ALERT OPERATORS TRANSMISSION - AOT AOT ref: A71P016-19 Rev 00 Page 9 of 16 Date: 15-JUL-2019 © AIRBUS S.A.S. 2019. ALL RIGHTS RESERVED. CONFIDENTIAL AND PROPRIETARY DOCUMENT Figure 7: P/N KH34697 and KH17548 Correct Installation (washer Outer Diameter is larger than bushing Inner Diameter) ### Page 10 ALERT OPERATORS TRANSMISSION - AOT AOT ref: A71P016-19 Rev 00 Page 10 of 16 Date: 15-JUL-2019 © AIRBUS S.A.S. 2019. ALL RIGHTS RESERVED. CONFIDENTIAL AND PROPRIETARY DOCUMENT PART 2 Pre SB 71-J014 – Refer to Figure 8 Correct P/N FK30900 Washers outer diameter measures 47,0 – 49,0 mm Figure 8: Washers (2) to be inspected on the Rear Mount Post SB 71-J014 – Refer to Figure 9 Correct P/N FK30900 Washers outer diameter measures 47,0 – 49,0 mm Figure 9: Washers (3) to be inspected on the Rear Mount ### Page 11 ALERT OPERATORS TRANSMISSION - AOT AOT ref: A71P016-19 Rev 00 Page 11 of 16 Date: 15-JUL-2019 © AIRBUS S.A.S. 2019. ALL RIGHTS RESERVED. CONFIDENTIAL AND PROPRIETARY DOCUMENT 2) TRENT XWB-97 Inspection On Engine 1 and Engine 2, perform a visual inspection of the primary pins washers: A) Rear Mount Washers Visual inspection to confirm that all washers installed on the rear mount are: - The correct P/N as per the location as described below, or - That the visual inspection corresponds to the correct picture, or - That the washers diameter measures within the specified range PART 1 Correct P/N KH51586 Washers outer diameter measures 56,0 – 58,0 mm Figure 10: Washers (3) to be inspected on the Rear Mount PART 2 Correct P/N KH51586 Washers outer diameter measures 56,0 – 58,0 mm Figure 11: Washers (2) to be inspected on the Rear Mount ### Page 12 ALERT OPERATORS TRANSMISSION - AOT AOT ref: A71P016-19 Rev 00 Page 12 of 16 Date: 15-JUL-2019 © AIRBUS S.A.S. 2019. ALL RIGHTS RESERVED. CONFIDENTIAL AND PROPRIETARY DOCUMENT PART 3 Correct P/N KH34697 Washers outer diameter measures 62,9 – 64,9 mm Figure 12: Washers (2) to be inspected on the Rear Mount PART 4 Correct P/N KH51586 Washers outer diameter measures 56,0 – 58,0 mm Figure 13: Washer (1) to be inspected on the Rear Mount ### Page 13 ALERT OPERATORS TRANSMISSION - AOT AOT ref: A71P016-19 Rev 00 Page 13 of 16 Date: 15-JUL-2019 © AIRBUS S.A.S. 2019. ALL RIGHTS RESERVED. CONFIDENTIAL AND PROPRIETARY DOCUMENT Figure 14: P/N KH51586 and KH34697 Correct Installation (washer Outer Diameter is larger than bushing Inner Diameter) ### Page 14 ALERT OPERATORS TRANSMISSION - AOT AOT ref: A71P016-19 Rev 00 Page 14 of 16 Date: 15-JUL-2019 © AIRBUS S.A.S. 2019. ALL RIGHTS RESERVED. CONFIDENTIAL AND PROPRIETARY DOCUMENT B) Thrust Links Washers Visual inspection to confirm that all 4 washers installed on the thrust link are: - The correct P/N KH52819, or - That the assembly visually corresponds to the correct picture, or - That the washers outer diameter measures 38,6 – 40,6 mm Figure 15: Washers (4) to be inspected on the Thrust Links Figure 16: KH52819 located close Figure 17: KH52819 located on the engine to the rear mount – correct (The two interface – correct (The two washers washers on the left side of Figure 15) on the right side of Figure 15) ### Page 15 ALERT OPERATORS TRANSMISSION - AOT AOT ref: A71P016-19 Rev 00 Page 15 of 16 Date: 15-JUL-2019 © AIRBUS S.A.S. 2019. ALL RIGHTS RESERVED. CONFIDENTIAL AND PROPRIETARY DOCUMENT 4.2.3 CLOSE UP The Thrust Reverser Cowls have to be closed as per Ref 8. The Fan Cowls have to be closed as per Ref 6 or Ref 7. The Thrust Reverser has to be disinhibited as per Ref 9. 4.2.4 FINDINGS 1) If the installed washer is correct a. No further action is required 2) If the installed washer is incorrect a. If the pin is in place, replace the washer with a correct one b. If the pin has moved axially, please contact AIRBUS for further disposition 3) Report to AIRBUS the compliance status and all the findings following the application of this AOT Inspections which took place before issuance of this AOT (P/N confirmation or visual inspection or measurement performed) can be used for compliance, provided that there has been no engine change since the inspection. 4.3 SPARES AND TOOLING Tools necessary to carry out the inspection: - A means to access the engine mounts and thrust links - Optionally, a means to measure the diameter with an accuracy of +/- 1mm Parts needed: - Washers potentially required: oFK30900 oKH17548 oKH34697 oKH51586 oKH52819 5. AOT APPROVAL The technical content of this document is approved under the authority of DOA nr. EASA.21J.031. 6. REPORTING Questions about this AOT are to be addressed to Airbus Customer Services through TechRequest on Airbus World, selecting Engineering Domain, Engineering Support Section and ATA 71-20/Topic A71P016-19. As per latest reporting policy (Ref to OIT 999.0018/16), inspection results (with or without findings) are to be addressed to Airbus Customer Services through the generic e-mail address: inspection.results@airbus.com. Best Regards, Christian FREMONT VICE PRESIDENT ENGINEERING SUPPORT CUSTOMER SERVICES Stéphane GOSSELIN VICE PRESIDENT A350 PROGRAMME CUSTOMER SERVICES ### Page 16 ALERT OPERATORS TRANSMISSION - AOT AOT ref: A71P016-19 Rev 00 Page 16 of 16 Date: 15-JUL-2019 © AIRBUS S.A.S. 2019. ALL RIGHTS RESERVED. CONFIDENTIAL AND PROPRIETARY DOCUMENT --- OpenAirDocs.org is an independent research project of [Contrail Labs](https://contraillabs.com/). 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