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: A71L004-14 Rev01 Page 1 of 6 Date: 07 APR 2014

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

SUBJECT: ATA 71 – AFT AND FWD ENGINE MOUNT BOLTS - TORQUE CHECK

AIRCRAFT TYPE: A330

OUR REF.: A71L004-14 Rev01 dated 07 APRIL 2014.

OUR PREV. REF.: A71L004-14 Rev00 dated 01 APRIL 2014.

0. REASON FOR REVISION

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

1. AIRCRAFT AFFECTED

Applicable to all A330 aircraft fitted with P&W engines within below effectivity and on engine(s) that was 

(were) never removed since Entry Into Service (EIS):

- From MSN0739 included,

- Till MSN1494 included.

2. REFERENCED DOCUMENTATION

2.1 APPENDIX

N/A

2.2 REFERENCES

AMM Task 24-42-00-861-801

AMM Task 71-13-00-010-802 

AMM Task 78-30-00-040-804

AMM Task 78-30-00-010-801 

AMM Figure 71-21-11-991-01100-06-A / SHEET 1

AMM Task 71-00-00-000-803

AMM Task 71-00-00-400-803 

AMM Figure 71-22-11-991-00800-06-A / SHEET 1

AMM Task 71-00-00-000-803 

AMM Task 78-30-00-410-801

AMM Task 78-30-00-440-804 

AMM Task 71-13-00-410-802

AMM Task 24-42-00-862-801

Airbus AMM Task 71-21-11 PB401

Airbus AMM Task 71-22-11 PB401

Airbus IPC Section 71-21-11-40

Airbus IPC Section 71-22-11-42

3. REASON
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: A71L004-14 Rev01 Page 2 of 6 Date: 07 APR 2014

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

3.1 FACTS

In July 2013, while performing an engine removal on an A330 aircraft at the Airbus Long Range (LR) 

Final Assembly Line (FAL) in Toulouse, one forward engine mount bolt was found not torqued.

The investigation concluded this was due to a human error during engine installation.

All other aircraft that were in the FAL were inspected and confirmed compliant.

Since January 2014 an improved process related to engine installation is applied in LR FAL.

However it is possible that some aircraft may have been delivered between Jun-2006 and Jan-2014 with 

under torqued bolts, and consequently a torque check of the AFT and FWD engine mount bolts is 

required.

3.2 CONSEQUENCES

Engine mounts are certified with a failsafe case considering one pylon bolt fully broken. However, it is 

possible that some aircraft may have been delivered with one or several bolt under-torqued.

3.3 AIM

The aim of this AOT is to provide operators with the instructions to perform a onetime torque check on 

the AFT and FWD engine mount bolts.

This AOT applies to aircraft within effectivity defined in paragraph 1 of this AOT and whose engines 

have never been removed since EIS.

4. SHORT TERM ACTION

4.1 PLANNING AND MANPOWER

4.1.1 ACCOMPLISHMENT TIMESCALE

Airbus requires that the inspections as per procedure described in paragraph 4.2, are carried out at first 

opportunity and no later than 2000FH after receipt of this “Alert Operators Transmission” or while 

applying ISB A330-71-3028 whichever occurs first.

4.1.2 MANPOWER

The estimated time to perform the inspection is 2 man-hours (MH) per engine:

- Get and close access: 1MH.

- Check Torque of aft and fwd Bolts: 1MH.

The estimated time to perform the corrective action(s) in case of findings is:

- Torqueing on an under-torqued bolt: 0,5 MH.

- Replacement of all fwd engine mount bolts and nuts:

o All bolts at once (requiring engine removal and then reinstallation): 10MH.

o One bolt at a time: 4MH.

- Replacement of all aft engine mount bolts and nuts:

o All bolts at once (requiring engine removal and then reinstallation): 10MH.

o One bolt at a time: 4MH.

4.2 DESCRIPTION

4.2.1 ACCESS
CUSTOMER SERVICES DIRECTORATE

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31707 BLAGNAC CEDEX FRANCE

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ALERT OPERATORS TRANSMISSION - AOT

AOT ref: A71L004-14 Rev01 Page 3 of 6 Date: 07 APR 2014

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4.2.1.1 Get access

Make sure that the safety devices and the warning notices are in position before you start a task on or 

near:

- The flight control.

- The flight control surfaces.

- The landing gear and the related doors.

- Components that move.

Movement of components can kill or injure persons.

Energize the ground service network as per AMM Task 24-42-00-861-801.

Make sure the engine 1 (2) has been shut down for a minimum of 5 minutes before doing this 

procedure.

Get access to the avionics compartment.

Then open, safety and tag these circuit breakers: 

- FOR FIN 4030EM1 (DEMOUNTABLE POWER PLANT ENG1) 

o Panel: 722VU / Designation: FADEC B ENG 1 / FIN: 13KS1 / Location: D44 

o Panel: 742VU / Designation: FADEC A ENG 1 / FIN: 12KS1 / Location: Q73 

- FOR FIN 4030EM2 (DEMOUNTABLE POWER PLANT ENG2) 

o Panel: 722VU / Designation: FADEC B ENG 2 / FIN: 13KS2 / Location: K49 

o Panel: 742VU / Designation: FADEC A ENG 2 / FIN: 12KS2 / Location: Q74 

Open the left and right aft fan cowl-doors as per AMM TASK 71-13-00-010-802: 

- FOR 4030EM1 (DEMOUNTABLE POWER PLANT ENG1), 415BL, 416BR.

- FOR 4030EM2 (DEMOUNTABLE POWER PLANT ENG2), 425BL, 426BR. 

Deactivate the thrust reverser for maintenance as per AMM TASK 78-30-00-040-804.

WARNING: YOU MUST DEACTIVATE THE THRUST REVERSER DIRECTIONAL CONTROL VALVE 

(DCV) BEFORE YOU WORK ON OR AROUND THE TRANSLATING COWL. IF YOU DO NOT 

DEACTIVATE THE DCV, YOU CAN CAUSE ACCIDENTAL THRUST REVERSER OPERATION AND 

INJURY TO PERSONS AND/OR DAMAGE TO EQUIPMENT.

Open the left and right thrust reverser cowl-doors as per AMM TASK 78-30-00-010-801: 

- FOR 4030EM1 (DEMOUNTABLE POWER PLANT ENG1), 417AL, 418AR.

- FOR 4030EM2 (DEMOUNTABLE POWER PLANT ENG2), 427AL, 428AR. 

4.2.1.2 Forward Engine mount

Put the ACCESS PLATFORM 1M (3FT) in position.

(Refer to Figure 71-21-11-991-01100-06-A / SHEET 1 - Forward Mount Torque Inspection)

Remove the forward mount safety hardware; retaining bolts, washers, nuts, plates, and locks at four 

locations. Keep these parts for installation. 

Proceed to torque check as detailed in paragraph 4.2.2.1 and proceed to corrective actions defined in 

4.2.3.1 in case of findings.
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1 ROND POINT MAURICE BELLONTE

31707 BLAGNAC CEDEX FRANCE

TELEPHONE + 33 (0)5 61 93 33 33

ALERT OPERATORS TRANSMISSION - AOT

AOT ref: A71L004-14 Rev01 Page 4 of 6 Date: 07 APR 2014

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Install the forward mount safety hardware, the retaining lock plates, nuts, washers, and bolts in four 

locations (Ref. AMM TASK 71-00-00-000-803) and (Ref. AMM TASK 71-00-00-400-803). 

4.2.1.3 Aft Engine mount

Put the ACCESS PLATFORM 3M (10 FT) - ADJUSTABLE in position.

(Refer to Figure 71-22-11-991-00800-06-A / SHEET 1 - Aft Mount Torque Inspection)

Remove the aft mount safety hardware; retaining bolts, washers, and lock plates at four locations. Keep 

these parts for installation (Ref. AMM TASK 71-00-00-000-803). 

Proceed to torque check as detailed in paragraph 4.2.2.2 and proceed to corrective actions defined in 

4.2.3.2 in case of findings.

Install the aft mount safety hardware, the retaining lock plates, washers, and bolts in four locations (Ref. 

AMM TASK 71-00-00-400-803).

4.2.1.4 Close Access

Make sure that the work area is clean and clear of tools and other items. 

Close the left and right thrust reverser cowl-doors as per AMM TASK 78-30-00-410-801: 

- FOR 4030EM1 (DEMOUNTABLE POWER PLANT ENG1), 417AL, 418AR.

- FOR 4030EM2 (DEMOUNTABLE POWER PLANT ENG2), 427AL, 428AR. 

Make the thrust reverser serviceable as per AMM TASK 78-30-00-440-804.

Get access to the avionics compartment. 

Then remove the safety clips and the tags and close these circuit breakers:

- FOR FIN 4030EM1 (DEMOUNTABLE POWER PLANT, ENG1) 

o Panel: 722VU / Designation: FADEC B ENG 1 / FIN: 13KS1 / Location: D44 

o Panel: 742VU / Designation: FADEC A ENG 1 / FIN: 12KS1 / Location: Q73 

- FOR FIN 4030EM2 (DEMOUNTABLE POWER PLANT, ENG2) 

o Panel: 722VU / Designation: FADEC B ENG 2 / FIN: 13KS2 / Location: K49 

o Panel: 742VU / Designation: FADEC A ENG 2 / FIN: 12KS2 / Location: Q74 

Close the left and right aft fan cowl doors as per AMM TASK 71-13-00-410-802):

- FOR 4030EM1 (DEMOUNTABLE POWER PLANT ENG1), 415BL, 416BR.

- FOR 4030EM2 (DEMOUNTABLE POWER PLANT ENG2), 425BL, 426BR. 

Remove all fixtures, tools, test and support equipment used during this procedure.

De-energize the ground service network as per AMM TASK 24-42-00-862-801.

4.2.2 INSPECTION REQUIREMENTS

4.2.2.1 Forward engine mount bolts

Mark the pylon bolt head and adjacent area to provide a reference point to indicate if the bolt moves.

Apply a torque of 4160lbf.in (47m.daN) in a clockwise direction (tightening direction) to all four engine 

forward mount pylon bolts, to check for a loose condition.
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: A71L004-14 Rev01 Page 5 of 6 Date: 07 APR 2014

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

4.2.2.2 Aft engine mount bolts

Mark the pylon bolt head and adjacent area to provide a reference point to indicate if the bolt moves.

Apply a torque of 3894lbf.in (44m.daN) in a clockwise direction (tightening direction) to all four engine aft 

mount pylon bolts, to check for a loose condition.

4.2.3 FINDINGS

4.2.3.1 Forward engine mount bolts

Check the marking applied in para 4.2.2.1 to confirm if the bolt has moved.

- One bolt rotates:

 For PAX aircraft with Average Flight Time (AFT) greater than 132 minutes having 

accumulated less than 2350FC / 24320FH since EIS,

 AND for PAX aircraft with AFT lower than 132 minutes having accumulated less than 

1950FC / 20210FH since EIS,

 AND for Freighter aircraft having accumulated less than 2140FC / 6600FH since EIS:

 Retorque the affected bolt as per task AMM 71-00-00-400-803-A (subtask 71-

00-00-420-141-A) between 5940 and 6600 lbf.in (67.12 and 74.58 m.daN) to 

be applied twice before next flight.

 Discard and replace the 4 bolts and associated nuts not later than (2350 FC / 

24320 FH or 1950 FC /20210 FH) for PAX or 2140 FC / 6600 FH for Freighter

as per AMM Task 71-21-11 PB401.

 For PAX aircraft with Average Flight Time (AFT) greater than 132 minutes having 

accumulated 2350FC / 24320FH or more since EIS,

 AND for PAX aircraft with AFT lower than 132 minutes having accumulated 1950FC / 

20210FH or more since EIS,

 AND for Freighter aircraft having accumulated 2140FC / 6600FH or more since EIS:

 Replace the 4 bolts and nuts before next flight as per AMM Task 71-21-11 

PB401.

- Several bolts rotate:

 Replace the 4 bolts and nuts before next flight as per AMM Task 71-21-11 PB401.

- One pylon bolt fully broken:

 Replace the 4 bolts and nuts before next flight as per AMM Task 71-21-11 PB401.

4.2.3.2 Aft engine mount bolts

Check the marking applied in para 4.2.2.2 to confirm if the bolt has moved.

**BEG. REV** 

- One bolt rotates:

 Retorque the affected bolt as per task AMM 71-00-00-400-803-A (subtask 71-00-00-

420-141-A) between 5520 and 6000 lbf.in (62.38 and 67.80 m.daN) to be applied twice

before next flight.

 Discard and replace the 4 bolts and nuts at next engine removal as per AMM Task 71-

22-11 PB401. 

**END REV**
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: A71L004-14 Rev01 Page 6 of 6 Date: 07 APR 2014

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

- Several bolts rotate:

 Replace the 4 bolts and nuts before next flight as per AMM Task 71-22-11 PB401.

- One pylon bolt fully broken:

 Replace the 4 bolts and nuts before next flight as per AMM Task 71-22-11 PB401.

4.3 SPARES AND TOOLING

4.3.1 Forward mount hardware

- Bolt part-number: 51U615

- Nut part-number: 51U671 

4.3.2 Aft mount hardware

- Bolt part-number: 51U616

- Nut part-number: 52U629

5. FURTHER INFORMATION

5.1 FOLLOW-UP PLAN

No further action is expected following AOT completion.

5.2 IMPACTED DOCUMENTATION

N/A

6. AOT APPROVAL

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:

Emilien DARTIGEAS

Nacelle Systems Product Leader UTAS

Customer Services - SEEE6

Phone: +33 (0)5 67 19 09 91 

Mobile: +33 (0)6 03 84 06 33

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

Mailto:emilien.dartigeas@airbus.com

Best Regards,

Jean-Luc MOUYSSET

VICE PRESIDENT ENGINEERING SUPPORT

CUSTOMER SERVICES

Philippe GOURDON

VICE PRESIDENT A330/A340 PROGRAMME

CUSTOMER SERVICES