Airbus All Operators Transmission A32W008-16

CUSTOMER SERVICES DIRECTORATE 1 ROND POINT MAURICE BELLONTE 31707 BLAGNAC CEDEX FRANCE TELEPHONE + 33 (0)5 61 93 33 33

ALERT OPERATORS TRANSMISSION - AOT AOT ref: A32W008-16 Rev 01 Page 1 of 5 Date: 30-JUL-2018 Date: 30-JUL-2018 © AIRBUS S.A.S. 2018. ALL RIGHTS RESERVED. CONFIDENTIAL AND PROPRIETARY DOCUMENT SUBJECT: ATA 32 – Main Landing Gear - Hinge Arm / Barrel pin inspection AIRCRAFT TYPE: A300,A300-600 OUR REF.: A32W008-16 Rev 01 dated 30-JUL-2018.

OUR PREV. REF.: A32W008-16 Rev 00 dated 25-Feb-2016

0. REASON FOR REVISION This AOT Rev 01 is issued to modify the compliance parameters to remove the benefit of MLG hinge arm / barrel pin last overhaul.

The revised paragraphs are indicated between **BEG. REV** and **END REV**.

1. AIRCRAFT AFFECTED All A300, A300-600 & A300-600ST aircraft

2. REFERENCED DOCUMENTATION

2.1 APPENDIX Appendix 1 - Area to be inspected Appendix 2 - Pictures of the area to be inspected with no crack Appendix 3 - Inspection flowchart Appendix 4 - Reporting sheet proforma

2.2 REFERENCES Ref 1: Aircraft Maintenance Manual 32-00-00 PB301 - Safety Precautions Ref 2: Aircraft Maintenance Manual 32-11-00 PB701 - Main Landing Gear - Cleaning Ref 3: Aircraft Maintenance Manual 32-11-11 PB401 – Main Landing Gear – Removal and Installation Ref 4: A300-600 Maintenance Planning Document Task 321100-07-1 Ref 5: A300 Maintenance Planning Document Task 321112-0504-1 Ref 6: Messier Bugatti Dowty: VSB 470-32-824 / 470-32-826 / 470-32-827 as applicable Ref 7: TFU 32.11.00.023

3. REASON The purpose of this AOT is to request operators to do a repetitive detailed visual inspection (DET) of the barrel hinge arm pin internal diameter (Ref appendix 1) to ensure the absence of any visible crack.

3.1 FACTS **BEG. REV** Three cases of cracked Hinge arm / Barrel pin have been reported to Airbus:

One case in-service identified during a maintenance task One case in-shop when MLG was returned for overhaul

ALERT OPERATORS TRANSMISSION - AOT AOT ref: A32W008-16 Rev 01 Page 2 of 5 Date: 30-JUL-2018 Date: 30-JUL-2018 © AIRBUS S.A.S. 2018. ALL RIGHTS RESERVED. CONFIDENTIAL AND PROPRIETARY DOCUMENT One case in-service observed during AOT A32W008-16 Rev 00 inspection Cracks have been identified on the internal diameter of the pin.

Part numbers of the pin potentially affected are:

C66441-X series C65543-X series **END REV**

3.2 CONSEQUENCES Failure of the pin could result in a MLG collapse.

3.3 AIM The aim of this AOT is to provide operators with instructions to perform an “on-wing” repetitive detailed visual inspection of the hinge arm/barrel pin internal diameter to ensure the absence of visible throughcrack.

3.4 INVESTIGATION **BEG. REV** The root cause of this crack has been determined and the failure scenario has been identified:

1. Vertical load of the MLG leg above certified limits, causing rupture of connecting rod bushes.

2. Modification of load distribution because of the migration of bush fragments

3. Stress level increase at the inner diameter of the hinge arm / barrel pin.

On top of this sequence, the weakening of pin material because of hydrogen material embrittlement is necessary to initiate a crack on the pin and to propagate it. The origin of this hydrogen is the corrosion found on the outer diameter of the pins found cracked in service.

As the overhaul process used before 2016 did not systematically imply chromium removal, Airbus believes that potential corrosion may not have been completely removed at that time. Therefore the compliance of the present AOT is modified for Rev 01 to remove the benefit of last pin overhaul.

**END REV**

4. SHORT TERM ACTION

4.1 PLANNING AND MANPOWER

4.1.1 ACCOMPLISHMENT TIMESCALE Within the compliance time specified in Table 1 of this AOT, as applicable, and thereafter at intervals not exceeding 100 Flights Cycles, inspect the pin in accordance with the instructions of paragraph

4.2.2.

ALERT OPERATORS TRANSMISSION - AOT AOT ref: A32W008-16 Rev 01 Page 3 of 5 Date: 30-JUL-2018 Date: 30-JUL-2018 © AIRBUS S.A.S. 2018. ALL RIGHTS RESERVED. CONFIDENTIAL AND PROPRIETARY DOCUMENT **BEG. REV** Table 1 - Initial Inspection Compliance time: Whichever occurs later between A and B A No later than 30 months since the pin first flight on an aircraft B Within 30 days after the effective date of the AOT Rev 01 **END REV** Repeat inspection every 100 Flight cycles (FC) When visual inspection is performed, even if no findings, it must be reported within 15 days to Airbus using the proforma provided in appendix 4 of this AOT after each inspection.

4.1.2 MANPOWER The manpower estimates given in this AOT are based on the direct labour cost to do the work. These estimates assume that the work will be done by experienced personnel, and may need to be revised upwards to suit operator’s circumstances. The estimates do not include the time to prepare, plan or inspect the work. Manufacturing and procurement of parts and tools, drying times for paints, sealants, etc., and general administration work are also not included.

Estimated time to perform visual inspection

- 0.5 hour elapsed time per aircraft

4.2 DESCRIPTION

4.2.1 ACCESS The detailed visual inspection:

- does not require A/C jacking.

- does not require any part removal.

The detailed visual inspection requires the aircraft to be placed in a maintenance configuration with Landing Gear safety devices installed as per Ref 1.

The detailed visual inspection requires an access platform and portable light.

ALERT OPERATORS TRANSMISSION - AOT AOT ref: A32W008-16 Rev 01 Page 4 of 5 Date: 30-JUL-2018 Date: 30-JUL-2018 © AIRBUS S.A.S. 2018. ALL RIGHTS RESERVED. CONFIDENTIAL AND PROPRIETARY DOCUMENT

4.2.2 INSPECTION REQUIREMENTS Refer to appendix 3 “inspection flowchart”

- Get access to the MLG Hinge arm/barrel pin using a ladder or access platform.

- Clean the inner diameter of the pin according to Ref 2.

- Without disassembly of the MLG or disconnection of the MLG door, perform a detailed visual inspection of the entire surface of the pin inner diameter (ID) to detect any presence of cracks.

- Refer to areas highlighted in the Appendices 1 & 2:

Use portable white light and mirror as necessary.

Report any relevant findings or absence of finding and take photos of the cleaned area.

4.2.3 FINDINGS In case of crack evidence, the complete MLG Leg has to be removed for shop inspection and replaced prior to next flight.

Refer to Ref 3 for MLG removal/installation.

If no crack, repeat the inspection detailed in paragraph 4.2.2 at an interval not exceeding 100 flight cycles (FC).

4.3 SPARES AND TOOLING In case of spare necessary, contact:

Safran Landing Systems Customer Support Center aogcsc.sls@safrangroup.com

5. FURTHER INFORMATION

5.1 FOLLOW-UP PLAN **BEG. REV** This AOT will be cancelled and replaced, or complemented by a new set of Service Bulletin. Information about resolution planning will be provided through Ref 7.

**END REV**

5.2 IMPACTED DOCUMENTATION Not applicable

6. AOT APPROVAL The technical content of this document is approved under the authority of DOA nr. EASA.21J.031.

ALERT OPERATORS TRANSMISSION - AOT AOT ref: A32W008-16 Rev 01 Page 5 of 5 Date: 30-JUL-2018 Date: 30-JUL-2018 © AIRBUS S.A.S. 2018. ALL RIGHTS RESERVED. CONFIDENTIAL AND PROPRIETARY DOCUMENT

7. REPORTING Questions about this AOT are to be addressed to Airbus Customer Services through TechRequest on Airbus World, selecting Engineering Domain and ATA 32-11.

Inspection results with or without findings are to be addressed to Airbus Customer Services to the following address: inspection.results@airbus.com Best Regards, Jean-Luc MOUYSSET

VICE PRESIDENT ENGINEERING SUPPORT

CUSTOMER SERVICES Olivier CRIOU HEAD OF A300/A310 PROGRAMME & CHIEF

ENGINEER

CUSTOMER SERVICES

REFERENCE; AOT 32W008-16 Page 1/1

APPENDIX 1

MAIN LANDING GEAR HINGE ARM / BARREL PIN INSPECTION

AREA TO BE INSPECTED

Fig.1: area to be inspected on MLG

Fig.2: zone of the pin to be inspected in green Barrel MLG door Pin to be inspected Hinge Arm Pin inner diameter full circumference

REFERENCE; AOT 32W008-16 Page 1/1

APPENDIX 2

MAIN LANDING GEAR HINGE ARM / BARREL PIN INSPECTION

PICTURES OF THE AREA TO BE INSPECTED WITH NO CRACK FOR REFERENCE

REFERENCE; AOT 32W008-16 APPENDIX 3

MAIN LANDING GEAR HINGE ARM / BARREL PIN INSPECTION

INSPECTION FLOWCHART No later than 30 months since the pin first flight on an aeroplane OR Within 30 days after the effective date of this AOT

WHICHEVER OCCURS LATER Detailed visual inspection (DET) of the internal diameter of the barrel/hinge arm pin to ensure absence of crack Perform Detailed visual inspection (DET) every 100 Flight cycles Crack ? YES Before next flight, replace the main landing gear and report to Airbus NO Return aircraft in service and report inspection results within 15 days

REFERENCE; AOT 32W008-16 Page 1/1

APPENDIX 4

MAIN LANDING GEAR HINGE ARM / BARREL PIN INSPECTION

PROFORMA FOR REPORTING RESULTS OF THE INSPECTION

Airbus requests the operator to fill in this proforma to report inspection findings even if no findings.

It must be used as well if damage is found. In that case, please provide photographic evidence.

Operator: Aircraft MSN:

Aircraft TSN: Aircraft CSN:

LH MLG PN: RH MLG PN:

LH MLG SN: RH MLG SN:

LH Hinge arm/Barrel pin PN: RH Hinge arm/Barrel p in PN:

LH Hinge arm/Barrel pin SN: RH Hinge arm/Barrel p in SN:

LH Pin CSN: RH Pin CSN:

LH PIN TSO: RH PIN TSO:

LH Pin CSO: RH PIN CSO:

Inspection Date:

------/------/------------

Findings:
Yes*
No *In case of findings, provide more information here below Additional information :

Return Proforma Inspection results with or without findings are to be addressed to Airbus Customer Services at the following address:

inspection.results@airbus.com