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: A71L008-14 Rev 01 Page 1 of 9 Date: 18-DEC-2014

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

SUBJECT: ATA 71 – TRENT 500 - AFT AND FWD ENGINE MOUNT BOLTS - TORQUE CHECK

AIRCRAFT TYPE: A340-500,A340-600

OUR REF.: A71L008-14 Rev 01 dated 18-DEC-2014.

OUR PREV. REF.: A71L008-14 Rev 00 dated 29-SEP-2014.

0. REASON FOR REVISION

The revision 01 is issued to include part numbers into aft engine mounts parts (Washer and Nut

Retainer) and the Engine Manual task references.

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

1. AIRCRAFT AFFECTED

Applicable to all A340-500/600 aircraft fitted with TRENT500 engines within below effectivity and on

engine(s) that was (were) never removed since first Entry Into Service (EIS):

- From MSN0715 included,

- Till MSN1122 included.

2. REFERENCED DOCUMENTATION

2.1 APPENDIX

N/A

2.2 REFERENCES

AMM Task 20-21-11

AMM Task 24-42-00-862-801

AMM Task 24-42-00-861-801

AMM Task 71-00-51-400-801-A

AMM Task 71-13-00-010-806

AMM Task 71-13-00-410-806

AMM Task 78-30-00-440-814

AMM Task 78-30-00-040-815

AMM Task 78-36-00-010-804

AMM Task 78-36-00-410-804

AIPC Figure 70 (Sheet 01/01) / 71-21-42

AIPC Figure 70 (Sheet 01/01) / 71-22-42

**BEG. REV**

Rolls-Royce Engine Illustrated Parts Catalogue Figure 71-21-11-01 FRONT MOUNT

Rolls-Royce Engine Illustrated Parts Catalogue Figure 71-21-12-01 REAR MOUNT
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**END REV**

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.

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

have never been removed since first 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”.

4.1.2 MANPOWER

The estimated time to perform the inspection is 3 man-hours (MH) per engine:

- Get and close access: 2 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 (get and close access time not included): 0,5 MH

- Replacement of all fwd engine mount bolts and nuts:

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

- Replacement of all aft engine mount bolts and nuts:

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

4.2 DESCRIPTION
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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.

WARNING: YOU MUST BE CAREFUL WHEN YOU DO WORK ON THE ENGINE PARTS AFTER

THE ENGINE IS SHUTDOWN. THE ENGINE PARTS CAN STAY HOT FOR ALMOST 1 HOUR. 

WARNING: YOU MUST NOT TOUCH HOT PARTS WITHOUT APPLICABLE GLOVES. HOT PARTS

CAN CAUSE AN INJURY. IF YOU GET AN INJURY PUT IT IN COLD WATER FOR 10 MINUTES

AND GET MEDICAL AID. 

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

Make sure the engine 1 (2) (3) (4) 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 an ACCESS PLATFORM 5M (16 FT)- ADJUSTABLE

Open, safety and tag these circuit breakers:

- FOR FIN 4040EM1 (DEMOUNTABLE POWER PLANT, ENG1)

o Panel: 722VU / Designation: T/R LOCKING ENG 1 / FIN: 3EG1 / Location: B44

o Panel: 722VU / Designation: FADEC B ENG 1 / FIN: 13KS1 / Location: K46

o Panel: 742VU / Designation: FADEC A ENG 1 / FIN: 12KS1 / Location: N74

- FOR FIN 4040EM2 (DEMOUNTABLE POWER PLANT, ENG2)

o Panel: 721VU / Designation: T/R LOCKING ENG 2 / FIN: 3EG2 / Location: G07

o Panel: 722VU / Designation: FADEC B ENG 2 / FIN: 13KS2 / Location: D43

o Panel: 742VU / Designation: FADEC A ENG 2 / FIN: 12KS2 / Location: Q73

- FOR FIN 4040EM3 (DEMOUNTABLE POWER PLANT, ENG3)

o Panel: 722VU / Designation: T/R LOCKING ENG 3 / FIN: 3EG3 / Location: F41

o Panel: 722VU / Designation: FADEC B ENG 3 / FIN : 13KS3 / Location: K47

o Panel: 742VU / Designation: FADEC A ENG 3 / FIN : 12KS3 / Location: Q74

- FOR FIN 4040EM4 (POWER PLANT-DEMOUNTABLE, ENG4)

o Panel: 721VU / Designation: T/R LOCKING ENG 4 / FIN: 3EG4 / Location: C04

o Panel: 722VU / Designation: FADEC B ENG 4 / FIN : 13KS4 / Location: D44

o Panel : 742VU / Designation : FADEC A ENG 4 / FIN : 12KS4 / Location: N75

Open the fan cowl doors as per AMM Task 71-13-00-010-806:

- For 4040EM1 (POWERPLANT- DEMOUNTABLE, ENG1) 415AL, 416AR

- For 4040EM2 (POWERPLANT- DEMOUNTABLE, ENG2) 425AL, 426AR

- For 4040EM3 (POWER PLANT-DEMOUNTABLE, ENG3) 435AL, 436AR

- For 4040EM4 (POWER PLANT-DEMOUNTABLE, ENG4) 445AL, 446AR
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Deactivate the thrust reverser for maintenance as per AMM Task 78-30-00-040-815

WARNING: YOU MUST DEACTIVATE THE THRUST REVERSER BEFORE YOU DO WORK ON OR

AROUND IT. IF YOU DO NOT, THE THRUST REVERSER CAN OPERATE ACCIDENTALLY AND

CAUSE INJURY AND/OR DAMAGE.

Open the thrust reverser doors as per AMM Task 78-36-00-010-804:

- FOR 4040EM1 (POWER PLANT-DEMOUNTABLE, ENG1), 417AL, 418AR.

- FOR 4040EM2 (POWER PLANT-DEMOUNTABLE, ENG2), 427AL, 428AR.

- FOR 4040EM3 (POWER PLANT-DEMOUNTABLE, ENG3), 437AL, 438AR.

- FOR 4040EM4 (POWER PLANT-DEMOUNTABLE, ENG4), 447AL, 448AR

4.2.1.2 Forward Engine mount

Put an ACCESS PLATFORM 5M (16 FT)- ADJUSTABLE in position at the side of the engine.

Remove Forward Mount Bolt Retaining assy.

(Refer to AIPC Figure 70 (Sheet 01/01) / 71-21-42)

- Remove the bolts (items 10 and 15), washers (item 30), nuts (items 45 and 50), brackets (items

60) and plates (items 70 and 80) from the four bolts (item 20).

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. Refer to paragraph 4.3 for bolts, nuts and washers part numbers.

Install Forward Mount Bolt Retaining assy.

(Refer to AIPC Figure 70 (Sheet 01/01) / 71-21-42)

- Install the bolts (items 10 and 15), washers (item 30), nuts (items 45 and 50), brackets (items

60) and plates (items 70 and 80) on the four bolts (item 20). Apply torque as per standard

practices AMM 20-21-11.

Remove the ACCESS PLATFORM 5M (16 FT).

4.2.1.3 Aft Engine mount

Install an ACCESS PLATFORM 5M (16 FT)- ADJUSTABLE in position at the side of the engine.

Remove Aft Mount Bolt Retaining assy.

(Refer to AIPC Figure 70 (Sheet 01/01) / 71-22-42)

- Remove the bolt (item 10), washer (item 40), and retainer (items 90) on bolt head side from the

four bolts (item 30).

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. Refer to paragraph 4.3 for bolts, nuts and washers part numbers.

Install Aft Mount Bolt Retaining assy.

(Refer to AIPC Figure 70 (Sheet 01/01) / 71-22-42)

- Install the bolt (item 10), washer (item 40), and retainers (items 90) from the four bolts (item 30).

- Torque the bolts (item 10) as per standard practices specified into AMM task 20-21-11.

Remove the ACCESS PLATFORM 5M (16 FT)- ADJUSTABLE.

4.2.1.4 Close Access

Put the ACCESS PLATFORM 5M (10 FT) ADJUSTABLE in position.
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© AIRBUS S.A.S. 2014. ALL RIGHTS RESERVED. CONFIDENTIAL AND PROPRIETARY DOCUMENT

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

Close the thrust reverser cowl doors as per AMM Task 78-36-00-410-804:

- FOR 4040EM1 (DEMOUNTABLE POWER PLANT, ENG1), 417AL, 418AR.

- FOR 4040EM2 (POWER PLANT-DEMOUNTABLE, ENG2), 427AL, 428AR.

- FOR 4040EM3 (POWER PLANT-DEMOUNTABLE, ENG3), 437AL, 438AR.

- FOR 4040EM4 (POWER PLANT-DEMOUNTABLE, ENG4), 447AL, 448AR

Make the thrust reverser serviceable after maintenance as per AMM Task 78-30-00-440-814.

Close the fan cowl doors as per AMM Task 71-13-00-410-806:

- For 4040EM1 (POWERPLANT- DEMOUNTABLE, ENG1) 415AL, 416AR

- For 4040EM2 (POWERPLANT- DEMOUNTABLE, ENG2) 425AL, 426AR

- For 4040EM3 (POWER PLANT-DEMOUNTABLE, ENG3) 435AL, 436AR

- For 4040EM4 (POWER PLANT-DEMOUNTABLE, ENG4) 445AL, 446AR

Remove the access platform(s).

Get access to the avionics compartment.

Remove the safety clips and the tags and close these circuit breakers:

- FOR FIN 4040EM1 (DEMOUNTABLE POWER PLANT, ENG1)

o Panel: 722VU / Designation: T / R LOCKING ENG 1 / FIN: 3EG1 / Location: B44

o Panel: 722VU / Designation: FADEC B ENG 1 / FIN: 13KS1 / Location: K46

o Panel: 742VU / Designation: FADEC A ENG 1 / FIN: 12KS1 / Location: N74

- FOR FIN 4040EM2 (DEMOUNTABLE POWER PLANT, ENG2)

o Panel: 721VU / Designation: T / R LOCKING ENG 2 / FIN: 3EG2 / Location: G07

o Panel: 722VU / Designation: FADEC B ENG 2 / FIN: 13KS2 / Location: D43

o Panel: 742VU / Designation: FADEC A ENG 2 / FIN: 12KS2 / Location: Q73

- FOR FIN 4040EM3 (DEMOUNTABLE POWER PLANT, ENG3)

o Panel: 722VU / Designation: T / R LOCKING ENG 3 / FIN: 3EG3 / Location: F41

o Panel: 722VU / Designation: FADEC B ENG 3 / FIN : 13KS3 / Location: K47

o Panel: 742VU / Designation: FADEC A ENG 3 / FIN : 12KS3 / Location: Q74

- FOR FIN 4040EM4 (POWER PLANT-DEMOUNTABLE, ENG4)

o Panel: 721VU / Designation: T / R LOCKING ENG 4 / FIN: 3EG4 / Location: C04

o Panel: 722VU / Designation: FADEC B ENG 4 / FIN : 13KS4 / Location: D44

o Panel : 742VU / Designation : FADEC A ENG 4 / FIN : 12KS4 / Location: N75

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 all four pylon bolts head and the adjacent area to provide a reference point to indicate if the bolt

moves.

Apply a torque of 3540.4lbf.in (40m.daN) in a clockwise direction (tightening direction) to all four engine

forward mount pylon bolts, to check for a loose condition.

4.2.2.2 Aft engine mount bolts
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Mark all four pylon bolts head and the adjacent area to provide a reference point to indicate if the bolt

moves.

Apply a torque of 4248.5lbf.in (48m.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

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 Before next flight,

o Re-torque twice the affected bolt as per AMM Task 71-00-51-400-801-A

(subtask 71-00-51-420-050-A) between 57 and 67.5m.daN (420.35 and 497.79

lbf.ft).

o At next engine removal,

o Discard and replace the 4 bolts and nuts and washers by new ones, and

proceed to inspections check. Refer to paragraph 4.2.3.1.2 for procedure

details.

- If several bolts rotate:

o Contact Airbus for further actions before next flight

- If one pylon bolt fully broken:

o Discard and replace the 4 bolts and nuts and washers with new ones before next flight

and proceed to inspections check. Refer to paragraph 4.2.3.1.2 for procedure details.

NOTE: Inspection results with or without findings have to be sent to Airbus Customer Services

Engineering.

4.2.3.1.2 Procedure details

Bolt replacement off-wing and Inspection to carry out:

- Proceed to engine removal as per AMM Task 71-00-51 PB401.

- Remove retaining hardware from all bolts.

- Remove and replace the 4 bolts and associated nuts and washers by new ones.

- Perform Fluorescent Penetrant Inspection and dimensional check on impacted forward engine

mount platform when engine is removed

o If nil finding, replace the forward platform at next engine removal

o If local deformation is exhibited during the check, replace the forward platform before

next flight

- Install the retaining hardware on all bolts.

- Install the engine as per AMM Task 71-00-51 PB401.

**BEG. REV**

NOTE: In case of one pylon bolt is found under-torqued, the forward Platform items that have to be

checked are 400 and 500 on RR Engine Illustrated Parts Catalogue (see Chapter 71 Power Plant ->

Figure 71-21-11-01 FRONT MOUNT). Refer to the Rolls-Royce Engine Manual to perform the

Fluorescent Penetrant Inspection and the dimensional checks.
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**END REV**

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 Before next flight,

o Re-torque twice the affected bolt as per AMM task 71-00-51-400-801-A

(subtask 71-00-51-420-050-A) between 68 and 81m.daN (501.47 and 597.35

lbf.ft).

o At next engine removal,

o Discard and replace the 4 bolts and nuts and washers by new ones, and

proceed to inspections. Refer to paragraph 4.2.3.2.2 for procedure details

- If several bolts rotate:

o Contact Airbus for further actions before next flight

- If one pylon bolt fully broken:

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

to inspections check. Refer to paragraph 4.2.3.2.2 for procedure details.

NOTE: Inspection results with or without findings have to be sent to Airbus Customer Services

Engineering.

4.2.3.2.2 Procedure details

Bolt replacement off-wing and Inspection to carry out:

- Proceed to engine removal as per AMM Task 71-00-51 PB401.

- Remove retaining hardware from all bolts.

- Remove and replace the 4 bolts and associated nuts and washers by new ones.

- Perform Fluorescent Penetrant Inspection and dimensional check on impacted rear engine

mount hardware when engine is removed

o If nil finding, replace the rear beam at next engine removal

o If local deformation is exhibited during the check, replace the rear beam before next

flight.

- Install the retaining hardware on all bolts.

- Install the engine as per AMM Task 71-00-51 PB401.

**BEG. REV**

NOTE: In case of one pylon bolt is found under-torqued, the Aft Beam (Rear Mount Beam) item that has

to be checked is 600 on Rolls-Royce Engine Illustrated Parts Catalogue (see Chapter 71 Power Plant ->

Figure 71-21-12-01 REAR MOUNT). Refer to the Rolls-Royce Engine Manual to perform the

Fluorescent Penetrant Inspection and the dimensional checks.

**END REV**

4.3 SPARES AND TOOLING

4.3.1 Forward mount hardware
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- Bolt part-number: BLT5468 / FW33110

- Nut part-number: U755355

- Washer part-number: UP11304

4.3.2 Aft mount hardware

- Bolt part-number: BLT5681

- Nut part-number: U755357

**BEG. REV**

- Washer part-number: UP11493

- Nut Retainer part-number: U755358

**END REV**

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:

Virginie HIRTZ

Nacelle Systems and Structure Engineer

Engineering Support - SEEE6

CUSTOMER SERVICES

Phone +33 (0)5 82 05 61 81

Fax +33 (0)5 61 93 36 14

Mailto: virginie.hirtz@airbus.com

Best Regards,

Jean-Luc MOUYSSET

VICE PRESIDENT ENGINEERING SUPPORT

CUSTOMER SERVICES

Philippe GOURDON

VICE PRESIDENT SUPPORT LR PROGRAMME

CUSTOMER SERVICES
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