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: A53W005-14 Page 1 of 7 Date: 22-APR-2014

© AIRBUS S.A.S. 2014. ALL RIGHTS RESERVED. CONFIDENTIAL AND PROPRIETARY DOCUMENT

SUBJECT: ATA 53 – INSPECTION OF THE AFT CARGO DOOR SILL BEAM AREA

AIRCRAFT TYPE: A300-600,A310

OUR REF.: A53W005-14 dated 22-APR-2014

1. AIRCRAFT AFFECTED 

A300-600/A310 aircraft (A/C) post-mod 05438 and pre-mod 12046; having accumulated more than 

18000 FC from A/C first flight at time of AOT issuance date.

Concerned A/C have been defined in 2 batches:

Batch 1: A/C having accumulated more than 30000FC from A/C first flight at time of AOT 

issuance

Batch 2: A/C having accumulated more than 18000FC and less than 30000FC from A/C first 

flight at time of AOT issuance

2. REFERENCED DOCUMENTATION

2.1 APPENDIX

Appendix 1: For A300-600: extract from IPC 25-52-04 fig 2

For A310 extract from IPC 25-52-26 fig 1 and 3

2.2 REFERENCES

Ref.1: For A300-600 SRM 53-17-18 fig.4 item 280A

For A310 SRM 53-17-18 fig 2 item 335A

Ref.2: For A300-600 SRM 53-17-18 fig.4 item 395

For A310 SRM 53-17-88 fig 2 item 15A

Ref.3: For A300-600 SRM 53-17-88 fig.2 item 15A

For A310 SRM 53-17-18 fig 2 item 525

Ref.4: AMM 52-30-00

Ref.5: AMM 53-10-33

Ref.6: AMM 25-52-22

Ref.7: AMM 25-50-21

Ref.8: For A300-600 TD/K4/T1/45810/2014, ISSUE A

For A310 TD/K4/T1/45811/2014, ISSUE A

Ref.9: For A300-600 TD/K4/T1/45808/2014, ISSUE A

For A310 TD/K4/T1/45809/2014, ISSUE A

Ref. 10: For A300-600 TD/K4/T1/45814/2014, ISSUE A

For A310 TD/K4/T1/45813/2014, ISSUE A

Ref 11: NTM 51-10-01

3. REASON

3.1 FACTS
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AOT ref: A53W005-14 Page 2 of 7 Date: 22-APR-2014

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Mod 05438: Doors and emergency exit – change frames and sills material and modify surface 

protection, embodied in production on MSN 388, 391, 395, 398, 401, 405, 408, 411, 

from MSN 414 to MSN 804 and from MSN 836 to 838

Mod 12046: Rear fuselage – Introduce enlarged rear lower deck cargo door embodied in production 

from MSN 805 to 835 and from MSN 839 to 878

During accomplishment of Maintenance Review Board Report (MRBR) task 531625-01-1 on an A300-

600 aircraft having accumulated more than 25000 FC from first flight, multiple fatigue cracks have been 

found on the following parts (Part Number P/N effective for inspected A/C):

 Aft cargo door sill beam: P/N A53973085210 (Ref.1)

 Lock fitting: P/N A53978239002 (Ref.2)

 Torsion box plate: P/N A53973318206 (Ref.3)

All damaged parts required replacement.

Further to this crack damage, a stress analysis was launched during which it was found that there is no 

dedicated fatigue scheduled maintenance task to monitor this area. Therefore, all aircraft in effectivity 

must be inspected within the required timeframe. 

3.2 CONSEQUENCES

The loss of more than one lock fitting could lead to a loss of the door locking function and subsequently 

a complete loss of the cargo door in flight with associated potential risk of rapid decompression.

3.3 AIM

This AOT calls for a repetitive Ultrasonic (US) inspection of the aft cargo door sill beam external area 

(refer to ref.9); up to the accomplishment of a one-time High Frequency Eddy Current (HFEC) inspection

of the internal structure (refer to ref.10), terminating for this AOT.

A Detailed Inspection (DET) has been developed as an alternative method to the US inspection (refer to 

ref. 8)

4. SHORT TERM ACTION

4.1 PLANNING AND MANPOWER

4.1.1 ACCOMPLISHMENT TIMESCALE

Batch 1 A/C: The first US inspection (ref.9) described in paragraph 4.2.2.2 must be performed on all 

aircraft within 50 FC from AOT issuance date.

 Then, repeated at intervals not exceeding 275 FC.

 Up to accomplishment of the terminating one-time HFEC inspection (ref.10)

Batch 2 A/C: The first US inspection (ref.9) described in paragraph 4.2.2.2 must be performed on all 

aircraft within 275 FC from AOT issuance date, not exceeding 30050FC from A/C first flight:

 Then, repeated at intervals not exceeding 275 FC.

 Up to accomplishment of the terminating one-time HFEC inspection (ref.10)

In case it is not possible to perform the US inspection, it is required to use alternative DET described in 

Ref 8.
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We recommend operators to perform the HFEC inspection at the earliest maintenance opportunity in 

order to minimize the risk of findings which will require the replacement of the sill beam.

Please note that once the HFEC inspection is performed, no further action is required in the scope of 

this AOT: HFEC inspection cancel the first and repetitive US inspection requirement.

4.1.2 MANPOWER

4.1.2.1 DET OF THE INTERNAL STRUCTURE

The estimated time to perform the inspection is: 2MH (excluding access and close up)

Note: the estimated time for access as described in § 4.2.1.1 is 3.5MH

the estimated time for close up as described in § 4.2.3.1 is 3.5MH

4.1.2.2 US INSPECTION OF THE EXTERNAL STRUCTURE 

The estimated time to perform the inspection is: 4 to 5 MH (excluding access and close up)

Note: the estimated time for access as described in § 4.2.1.2 is 0.2MH

the estimated time for close up as described in § 4.2.3.2 is 0.2MH

4.1.2.3 HFEC INSPECTION OF THE INTERNAL STRUCTURE 

The estimated time to perform the inspection is: 3.5MH (excluding access and close up)

Note: the estimated time for access as described in § 4.2.1.3 is 3.5MH

the estimated time for close up as described in § 4.2.3.3 is 3.5MH

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.

4.2 DESCRIPTION

4.2.1 ACCESS

- WARNING 1: STOP THE OPENING PROCEDURE IF THE RED WARNING LIGHT FLASHES. 

RESIDUAL PRESSURE COULD CAUSE THE CARGO COMPARTMENT DOOR TO OPEN WITH A 

SUDDEN FORCE AND INJURE PERSONS AND/OR DAMAGE THE AIRCRAFT. 

WARNING 2: BEFORE SUPPLYING AIR BY EXTERNAL SOURCE OR APU MAKE CERTAIN THAT: 

- AT LEAST ONE FLT COMPT WINDOW OR CABIN DOOR IS OPEN AND REMAINS OPEN DURING 

SERVICING. 

- IF THE A/C IS PARKED OUTSIDE AND IS NOT PROTECTED FROM THE RAIN, ONE 

MAINTENANCE DOOR SUCH AS 134AR, 136AR, OR AVIONICS ACCESS DOOR 121BL IS OPEN 

AND REMAINS OPEN DURING SERVICING. 

4.2.1.1 DET OF THE INTERNAL STRUCTURE

 Put access platforms in position below the aft cargo door.

 Open the aft cargo door 812 as per AMM ref.4:
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 Remove the aft cargo floor panels and ball mats in the vicinity of the aft cargo door as per ref.5 

and ref.6.

 Remove the heat and sound insulation in the vicinity of the aft cargo door sill beam area as per 

ref.7.

 Remove the Power Drive Unit (PDU) bracket (Refer to appendix 1 for more details)

4.2.1.2 US INSPECTION OF THE EXTERNAL STRUCTURE

 Put access platforms in position below the aft cargo door.

 Open the aft cargo door 812 as per AMM ref.4:

4.2.1.3 HFEC INSPECTION OF THE INTERNAL STRUCTURE

 Put access platforms in position below the aft cargo door.

 Open the aft cargo door 812 as per AMM ref.4:

 Remove the aft cargo floor panels and ball mats in the vicinity of the aft cargo door as per ref.5 

and ref.6.

 Remove the heat and sound insulation in the vicinity of the aft cargo door sill beam area as per 

ref.7.

 Remove the PDU bracket (Refer to appendix 1 for more details)

4.2.2 INSPECTION REQUIREMENTS

4.2.2.1 DET OF THE INTERNAL STRUCTURE 

 Perform DET of the internal structure as per Ref.8.

4.2.2.2 US INSPECTION OF THE EXTERNAL STRUCTURE 

 Perform US inspection of the external structure as per Ref.9

4.2.2.3 HFEC INSPECTION OF THE INTERNAL STRUCTURE 

 Perform HFEC inspection of the internal structure as per Ref.10.

4.2.3 CLOSE-UP

4.2.3.1 DET OF THE INTERNAL STRUCTURE

 Install the PDU bracket (Refer to appendix 1 for more details)

 Install the heat and sound insulation in the vicinity of the aft cargo door sill beam area as per 

ref.7.

 Install the aft cargo floor panels and ball mats in the vicinity of the aft cargo door as per ref.5 

and ref.6.

 Close the aft cargo door 812 as per AMM ref.4

 Remove access platforms in position below the aft cargo door.

4.2.3.2 US INSPECTION OF THE EXTERNAL STRUCTURE 

 Close the aft cargo door 812 as per AMM ref.4.

 Remove access platforms in position below the aft cargo door.

4.2.3.3 HFEC INSPECTION OF THE INTERNAL STRUCTURE
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AOT ref: A53W005-14 Page 5 of 7 Date: 22-APR-2014

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 Install the PDU bracket (Refer to appendix 1 for more details)

 Install the heat and sound insulation in the vicinity of the aft cargo door sill beam area as per 

ref.7.

 Install the aft cargo floor panels and ball mats in the vicinity of the aft cargo door as per ref.5 

and ref.6.

 Close the aft cargo door 812 as per AMM ref.4.

 Remove access platforms in position below the aft cargo door.

4.2.4 FINDINGS

In case of findings during DET, US inspection or HFEC inspection, before next flight, please contact 

Airbus to get further instructions:

AIRBUS contacts:

SEOE1/SEOE2/SEOE3 

Customer Services

Fax: +33 (0)5 61 93 28 73

Mailto: region1.StructureRepairSupport@airbus.com

region2.StructureRepairSupport@airbus.com

region3.StructureRepairSupport@airbus.com

Or for AOG request:

AIRTAC (Airbus Technical AOG Center)

Customer Services

Phone: +33 (0)5 61 93 34 00

Fax: +33 (0)5 61 93 35 00

Mailto: airtac@airbus.com

Note:

In case of findings on lock fitting(s) through ref. 8, be aware that removal of damaged lock fitting(s) is 

required and an inspection is necessary in the scope of damage assessment.

This inspection consists in a rototest as per ref. 11, immediately after damaged lock fitting removal, on 

fastener holes at lock fitting with sill beam web attachment

4.3 SPARES AND TOOLING

In case of findings leading to part replacement, associated spare parts have been speculated

5. FURTHER INFORMATION

5.1 FOLLOW-UP PLAN

This AOT will be cancelled and superseded by new mandatory Inspection Service Bulletins, which will 

be available by end of 2014.

5.2 IMPACTED DOCUMENTATION

N/A

6. AOT APPROVAL
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AOT ref: A53W005-14 Page 6 of 7 Date: 22-APR-2014

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

7. REPORTING

Questions about this AOT and inspection results with or without findings are to be sent to Airbus 

Customer Services engineering as soon as possible, after the AOT application, to the attention of:

Stéphanie VERON

Structure Engineer

Structure Engineering – SEES1

CUSTOMER SERVICES

Phone: +33 (0)5 61 18 80 06

Fax: +33 (0)5 61 93 36 14 

Mailto: stephanie.veron@airbus.com

Best Regards,

Jean-Luc MOUYSSET

VICE PRESIDENT ENGINEERING SUPPORT

CUSTOMER SERVICES

Philippe BOUCHERAT

VICE PRESIDENT A300/A310 FAMILY 

PROGRAMME

CUSTOMER SERVICES
ALERT OPERATORS TRANSMISSION - AOT

AOT ref: A53W005-14 Page 7 of 7 Date: 22-APR-2014

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Appendix :