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: A71L006-14 Page 1 of 10 Date: 22-JUL-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.: A71L006-14 dated 22-JUL-2014

1. AIRCRAFT AFFECTED

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

(were) never removed since aircraft first flight:

- From MSN0733 included,

- Till MSN1507 included.

2. REFERENCED DOCUMENTATION

2.1 REFERENCES

AMM Task 24-42-00-861-801

AMM Task 71-13-00-010-803

AMM Task 78-31-00-040-802

AMM Task 78-36-00-010-802

AMM Task 71-13-00-010-804

AMM Task 75-31-51-710-801

AMM Figure 71-21-41-991-03100-06-A / SHEET 1 - Core Electrical Harness

AMM Figure 71-21-41-991-03200-06-A / SHEET 1 - Forward Engine Mount

AMM Figure 71-21-41-991-03200-06-A / SHEET 1 - Forward Engine Mount

AMM Figure 71-21-41-991-03100-06-A / SHEET 1 - Core Electrical Harness

Airbus IPC Section 71-21-11

Airbus IPC Section 71-22-41

AMM Task 71-13-00-410-804

AMM Task 78-36-00-410-802

AMM Task 78-31-00-440-802

AMM Task 71-13-00-410-803

AMM Task 71-00-00-720-811

AMM Task 30-21-00-710-801

AMM Task 29-11-00-710-801

AMM Task 29-12-00-710-802

AMM Task 29-13-00-710-801

AMM Task 36-11-00-710-807

AMM Task 24-21-00-710-804

AMM Task 24-42-00-862-801

AMM Figure 71-21-41-991-03200-06-A / SHEET 1 - Forward Engine Mount

AMM Figure 71-22-41-991-00200-06-A / SHEET 1 - Aft Engine Mount

AMM Task 71-00-00 PB401

Airbus MPD Task 712107-01
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3. REASON

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.

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”.

4.1.2 MANPOWER

The estimated time to perform the inspection is 4,5 man-hours (MH) per engine:

- Get and close access: 3,5 MH.

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

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 engine removal and then reinstallation: 10 MH

- Replacement of all aft engine mount bolts and nuts:

o engine removal and then reinstallation: 10 MH
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4.2 DESCRIPTION

4.2.1 ACCESS

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.

Put a WARNING NOTICE(S) to tell persons not to start the engines.

Get Access to the Avionics Compartment

- Put the ACCESS PLATFORM 3M (10 FT)- ADJUSTABLE in position at the access door 811.

- Open the access door 811.

- Open the protective door of the AC/DC emergency power-center 740VU. 

WARNING: MAKE SURE THAT YOU OPEN CIRCUIT BREAKERS 2DN1 AND 2DN2 TO DEENERGIZE THE ANTI-ICE VALVE (4000DN). IF THE VALVE IS NOT DE- ENERGIZED, IT IS VERY 

HOT, AND CAN THUS BURN PERSONNEL WHO DO WORK IN THIS AREA. 

Open, safety and tag these circuit breakers: 

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

o Panel: 721VU / Designation: ANTI ICE ENG 1 / FIN: 2DN1 / Location: W06 

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: 722VU / Designation: ANTI ICE ENG 2 / FIN: 2DN2 / Location: W39 

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

Open the fan cowl doors as per AMM Task 71-13-00-010-803:

- FOR 4030EM1 (DEMOUNTABLE POWER PLANT, ENG1), 415AL, 416AR.

- FOR 4030EM2 (DEMOUNTABLE POWER PLANT, ENG2), 425AL, 426AR.

Deactivate the thrust reverser for maintenance as per AMM Task 78-31-00-040-802 

Remove the aft engine mount access panels 

- FOR 4030EM1 (DEMOUNTABLE POWER PLANT, ENG1), 453AL, 453AR.

- FOR 4030EM2 (DEMOUNTABLE POWER PLANT, ENG2), 463AL, 463AR.
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© AIRBUS S.A.S. 2014. ALL RIGHTS RESERVED. CONFIDENTIAL AND PROPRIETARY DOCUMENT

Open the thrust reverser doors as per AMM Task 78-36-00-010-802: 

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

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

Open the core cowl doors as per AMM Task 71-13-00-010-804: 

- FOR 4030EM1 (DEMOUNTABLE POWER PLANT, ENG1), 414AL, 414AR.

- FOR 4030EM2 (DEMOUNTABLE POWER PLANT, ENG2), 424AL, 424AR.

NOTE: The Variable Bleed Valve (VBV) doors must be pumped closed any time maintenance is 

performed in the area. This is so unwanted material does not go into the core inlet through the VBV 

doors. 

Close the VBV doors (Ref. AMM Task 75-31-51-710-801). 

4.2.1.2 Forward Engine mount

The following procedure is applicable to each engine.

Install an ACCESS PLATFORM 1M (3 FT).

Disconnection of the Electrical Connectors: 

(Refer to AMM figure 71-21-41-991-03100-06-A / SHEET 1 - Core Electrical Harness)

NOTE: Disconnect the electrical connectors surrounding the pylon to allow full access to the heads of 

the pylon bolts. 

- Disconnect the connectors that follow from the left side of the pylon junction box. 

o Disconnect the connector, 3827VC-A, on the hydraulic pump harness (29) from the 

receptacle, C5. Disconnect the connector, 3822VC-A, on the forward fire detector 

harness (28) from the receptacle, C2. Put blanking caps on the connectors and the 

receptacles.

o Disconnect the connector, 3828VC-A, on the IDG control harness (16) from the 

receptacle, C6. Disconnect the connector, 3825VC-A, on the IDG control harness (16) 

from the receptacle, C7. Put blanking caps on the connectors and the receptacles.

o Remove the three bolts and remove the bracket securing the harnesses (16) (28) and 

(29) to the pylon.

- Disconnect the connectors that follow from the right side of the pylon junction box.

o Disconnect and put blanking caps on these connectors and receptacles.

 The connector, 3821VC-A, on the right fire detector harness (19) from the 

receptacle, C1.

 The connector, 3820VC-A, on the right switch harness (20) from the 

receptacle, C4.

 The connector, 3829VC-A, on the right valve harness (21) from the receptacle, 

C8. 

o Remove the two bolts and remove the bracket holding the harnesses (19) (20) and (21) 

to the pylon. 

Remove Forward Mount Bolt Retainers Mount. 

(Refer to AMM Figure71-00-00-991-08300-04-A/ SHEET 1 - Forward Engine Mount)

- Remove the bolts (220), washers (221), nuts (223), and bolt retainers (224,225 and 226) from 

the five bolts ((4) 230 and (1) 240) 
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© AIRBUS S.A.S. 2014. ALL RIGHTS RESERVED. CONFIDENTIAL AND PROPRIETARY DOCUMENT

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.

Install Forward Mount Bolt Retainers 

(Refer to AMM Figure 71-21-41-991-03200-06-A / SHEET 1 - Forward Engine Mount)

Install the bolt retainers (224, 225 and 226), washers (221), bolts (220) and nuts (223) on the forward 

mount bolts (5 places).

- TORQUE bolts (220) between 55 and 70 lbf.in (0.62 and 0.79 m.daN). 

Connection of the Electrical Connectors:

(Refer to AMM Figure 71-21-41-991-03100-06-A / SHEET 1 - Core Electrical Harness)

- Connect the electrical harnesses to the left side of the pylon junction box that follows:

o Remove the protective covers from the hydraulic pump harness (29), the forward fire 

detector harness (28) and the IDG control harness (16). Remove the protective covers 

from the receptacles, C2, C5, C6, and C7, on the pylon junction box.

o Connect the connector, 3827VC-A, on the hydraulic pump harness (29) to the 

receptacle, C5. Tighten the connector.

o Connect the connector, 3822VC-A, on the forward fire detector harness (28) to the 

receptacle, C2. Tighten the connector.

o Connect the connector, 3828VC-A, on the IDG control harness (16) to the receptacle, 

C6. Tighten the connector.

o Connect the connector, 3825VC-A, on the IDG control harness (16) to the receptacle, 

C7. Tighten the connector.

o Attach harness bracket to the pylon with 3 bolts and washers. TORQUE bolts to 

between 50 and 70 lbf.in (0.57 and 0.79 m.daN). 

- Connect the electrical harnesses to the right side of the pylon junction box as follows:

o Remove the protective covers from the right fire detector harness (19), the right switch 

harness (20) and the right valve harness (21). Remove the protective covers from the

receptacles, C1, C4 and C8, on the pylon junction box.

o Connect the connector, 3821VC-A, on the right fire detector harness (19) to the 

receptacle, C1. Tighten the connector.

o Connect the connector, 3820VC-A, on the right switch harness (20) to the receptacle, 

C4. Tighten the connector.

o Connect the connector, 3829VC-A, on the right valve harness (21) to the receptacle, 

C8. Tighten the connector.

o Attach harness bracket to the pylon with 2 bolts and washers. TORQUE bolts to 

between 50 and 70 lbf.in (0.57 and 0.79 m.daN). 

Remove the ACCESS PLATFORM 1M (3 FT).

4.2.1.3 Aft Engine mount

The following procedure is applicable to each engine.

Install an ACCESS PLATFORM 1M(3 FT). 

Remove Aft Mount Bolt Retainers Mount. 

(Refer to AIPC Figure 20 (Sheet 01/01) – Section 71-22-41)

- Remove the self–locking nuts (item 180), flat washers (item 170), hex head bolts (item 160), 

and bolt retainers (item 190) from the four bolts (item 200). 
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© AIRBUS S.A.S. 2014. ALL RIGHTS RESERVED. CONFIDENTIAL AND PROPRIETARY DOCUMENT

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 Aft Mount Bolt Retainers 

(Refer to AIPC Figure 20 (Sheet 01/01) – Section 71-22-41)

- Install the self–locking nuts (item 180), flat washers (item 170), hex head bolts (item 160), and 

bolt retainers (item 190) from the four bolts (item 200).

- TORQUE bolts (160) between 55 and 70 lbf.in (0.62 and 0.79 m.daN). 

Remove the ACCESS PLATFORM 1M (3 FT).

4.2.1.4 Close Access

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 

o Panel: 721VU / Designation: ANTI ICE ENG 1 / FIN: 2DN1 / Location: W06 

- 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 

o Panel: 722VU / Designation: ANTI ICE ENG 2 / FIN: 2DN2 / Location: W39 

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

Put the ACCESS PLATFORM 3M (10 FT) ADJUSTABLE in position at the access door 811.

Close the protective door of the AC/DC emergency power center 740VU. 

Close the access door 811. 

Close the core cowl doors (Ref. AMM Task 71-13-00-410-804): 

- FOR 4030EM1 (DEMOUNTABLE POWER PLANT, ENG1), 414AL, 414AR.

- FOR 4030EM2 (DEMOUNTABLE POWER PLANT, ENG2), 424AL, 424AR.

Close the thrust reverser cowl doors as per AMM Task 78-36-00-410-802:

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

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

Install the aft engine mount access panels. 

- FOR 4030EM1 (DEMOUNTABLE POWER PLANT, ENG1), 453AL, 453AR.

- FOR 4030EM2 (DEMOUNTABLE POWER PLANT, ENG2), 463AL, 463AR.

Make the thrust reverser serviceable as per AMM Task 78-31-00-440-802. 

Remove the access platform(s).

Close the fan cowl doors as per AMM Task 71-13-00-410-803: 

- FOR 4030EM1 (DEMOUNTABLE POWER PLANT, ENG1), 415AL, 416AR.

- FOR 4030EM2 (DEMOUNTABLE POWER PLANT, ENG2), 425AL, 426AR.
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© AIRBUS S.A.S. 2014. ALL RIGHTS RESERVED. CONFIDENTIAL AND PROPRIETARY DOCUMENT

Do the tests that follow:

- Do a minimum idle leak check as per AMM Task 71-00-00-720-811.

- Do an operational test of the ice protection of the engine air intake as per AMM Task 30-21-00-

710-801.

- Do an operational test of the hydraulic pumps as per AMM Task 29-11-00-710-801:

o FOR 4030EM1 (DEMOUNTABLE POWER PLANT, ENG1) (Ref. AMM Task 29-12-00-

710-802)

o FOR 4030EM2 (DEMOUNTABLE POWER PLANT, ENG2) (Ref. AMM Task 29-13-00-

710-801) 

- Do the operational test of the bleed air system as per AMM Task 36-11-00-710-807.

- Do the operational test of the IDG as per AMM Task 24-21-00-710-804. 

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

(Refer to AMM Figure 71-00-00-991-08300-04-A/ SHEET 1 - Forward Engine Mount)

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

Apply a torque of 3363 lbf.in (38 m.daN) in a clockwise direction (tightening direction) to all five engine 

forward mount pylon bolts ((4) 230 and (1) 240), to check for a loose or broken bolt condition. 

4.2.2.2 Aft engine mount bolts

(Refer to AMM Figure 71-22-41-991-00200-06-A / SHEET 1 - Aft Engine Mount)

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

Apply a torque of 4868 lbf.in (55 m.daN) in a clockwise direction (tightening direction) to all four engine 

aft mount pylon bolts (270), to check for a loose or broken bolt condition.

4.2.3 FINDINGS

4.2.3.1 Forward engine mount bolts

4.2.3.1.1 Instructions.

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

- If one bolt rotates:

o Aircraft has accumulated less than 4000FC / 30800FH since first EIS:

 Retorque the affected bolt as per task 71-00-00-400-802-A (subtask 71-00-00-

420-054-A -> Between 54.23 m.daN (400 lbf.ft) and 61.01 m.daN (450 lbf.ft)

(to apply two times)) before next flight.

 Discard and replace one at the time the 5 bolts and associated nuts with new 

one not later than 4000FC/30800FH since first EIS.

Read paragraph 4.2.3.1.2 for bolt replacement via bootstrap installation or 

via engine removal.
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o Aircraft has accumulated 4000FC / 30800FH or more since first EIS:

 Discard and replace the 5 bolts and associated nuts with new one before next 

flight.

Read paragraph 4.2.3.1.2 for bolt replacement via engine removal.

- If several bolts rotate:

o Please contact Airbus for further actions.

- If one pylon bolt fully broken:

o Please contact Airbus as it’s required per subtask 71-21-41-720-050-A.

4.2.3.1.2 Procedure details.

Bolt replacement via bootstrap installation:

- Proceed to engine removal as per AMM Task 71-00-00 PB401 

- Perform Task 71-00-00-000-802-A up to subtask 71-00-00-020-053-A point (1)

- Discard and replace one at the time the 5 bolts and associated nuts with new one

- Proceed to the engine installation as per AMM Task 71-00-00 PB401.

Bolt replacement via engine removal:

- Proceed to engine removal as per AMM Task 71-00-00 PB401.

- Remove retaining hardware from all bolts.

- Discard and replace the 5 bolts and associated nuts with new one.

- Install the retaining hardware on all bolts.

- Install the engine as per AMM Task 71-00-00 PB401.

NOTE: At each engine Removal/Installation, a visual inspection of the mount assemblies and a nondestructive testing and running torque check of engine mount bolts have to be performed before 

engine installation as requested on subtask 71-00-00-630-057-A.

4.2.3.2 Aft engine mount bolts

4.2.3.2.1 Instructions.

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

- If one bolt rotates:

o Re-torque the affected bolt. as per task 71-00-00-400-802-A (subtask 71-00-00-420-

054-A) -> between 77.96 m.daN (575 lbf.ft) and 84.74 m.daN (625 lbf.ft) (to apply 

two times)) before next flight.

o Discard and replace the 4 bolts and nuts with new one at next engine removal.

Read paragraph 4.2.3.2.2 for procedure details.

- If several bolts rotate:

o Please contact Airbus for further actions.

- If one pylon bolt fully broken:

o Discard and replace the 4 bolts and nuts with new one before next flight.

 Read paragraph 4.2.3.2.2 for procedure details.
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4.2.3.2.2 Procedure details.

Bolt replacement:

- Proceed to engine removal as per AMM Task 71-00-00 PB401.

- Remove retaining hardware from all bolts.

- Discard and replace the 4 bolts and associated nuts with new one.

- Install the retaining hardware on all bolts.

- Install the engine as per AMM Task 71-00-00 PB401.

NOTE: At each engine removal/Installation, a visual inspection of the mount assemblies and a nondestructive testing and running torque check of engine mount bolts have to be performed before 

engine installation as requested on subtask 71-00-00-630-057-A.

4.3 SPARES AND TOOLING

4.3.1 Forward mount hardware

- Bolt part-number: 1322M97P04

- Nut part-number: 1322M30P03 

4.3.2 Aft mount hardware

- Bolt part-number: 1672M69P01

- Nut part-number: 1672M70P01

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 No. EASA.21J.031
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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