ALL OPERATORS TELEX - ALL OPERATORS TELEX

SUBJECT: A340-500/600 - ATA26 – FIRE DETECTION UNIT (FDU) QUALITY ISSUE

OUR REF: AOT A340-500/600-26A5024 dated 19 Apr 2011.

1.•AIRCRAFT AFFECTED

All A340-500/600 aircraft.

2.•REFERENCED DOCUMENTATION

REF. 1: •AMM task: 26-12-34-000-801-A - Removal of the Engine Fire

Detection Unit (FDU) (1WD1) (1WD3)

REF. 2:•AMM task: 26-12-34-000-802-A - Removal of the Engine Fire

Detection Unit (FDU) (1WD2) (1WD4)

REF. 3:•AMM task: 26-13-34-000-801-A – Removal of the APU FDU (13WG)

REF. 4:•AMM task: 26-11-34-000-801-A - Removal of the MLG Bay Fire

Detection Unit (FDU) (1WP)

REF. 5:•AMM task: 26-12-34-400-801-A - Installation of the Engine Fire

Detection Unit (FDU) (1WD1) (1WD3)

REF. 6: •AMM task: 26-12-34-400-802-A - Installation of the Engine Fire

Detection Unit (FDU) (1WD2) (1WD4)

REF. 7: •AMM task: 26-13-34-400-801-A – Installation of the APU FDU (13WG)

REF. 8: •AMM task: 26-11-34-400-801-A – Installation of the MLG Bay Fire

Detection Unit (FDU)(1WP)

3.•REASON

3.1•FACTS

FDU supplier L’HOTELLIER has reported a potential soldering quality issue

on one of the internal cards of some FDU P/N 3711-00. This soldering

quality issue, limited to a batch of FDU units, was caused by the

application of a specific manufacturing process. This FDU P/N 3711-00 can

be installed on A330 or A340 aircraft, all models.

3.2•CONSEQUENCES

This issue could lead to an undetected loss of the fire detection function

in the area that is monitored by the FDU (Engine or Main Landing Gear Bay

or APU).

3.3•AIM

The aim of this AOT is to provide operators with the list of serial numbers

of affected FDU units. This batch includes units delivered by L’HOTELLIER

as spare parts and units delivered on aircraft from the Airbus production

line. The units currently fitted on aircraft have to be replaced at the

earliest maintenance opportunity but no later than 1000 FH after receipt of

this AOT.

3.4•LIST OF AFFECTED FDUs

- Twenty three (23) FDU P/N 3711-00 are affected:

ZL0683

ZL0722

ZL0725

ZL0730

ZL0738

ZL0743

ZL0770

ZL0788

ZL0718

ZL0723
ZL0727

ZL0731

ZL0740

ZL0745

ZL0772

ZL0804

ZL0721

ZL0724

ZL0729

ZL0736

ZL0742

ZL0747

ZL0775

4.•SHORT TERM ACTION

4.1•PLANNING AND MANPOWER

4.1.1•PLANNING

a)•Within 1000 FH after receipt of this AOT, identify and replace the

suspect FDU S/Ns listed in paragraph 3.4 of this AOT, in accordance

with the instructions provided in paragraph 4.2 below. Send suspect

units back to L’HOTELLIER for repair (see focal point information in

paragraph 4.3.1. of this AOT).

a)•Upon receipt of this AOT, make sure that no FDU S/N listed in

paragraph 3.4 is installed on aircraft unless it has been repaired by

L’HOTELLIER (refer to paragraph 5. of this AOT).

4.1.2•MANPOWER

-•Approximately 0.25 hour is required for access to the avionics bay.

-•Approximately 0.25 hour is required to identify part number and serial

number of FDU FIN 1WD1 / 1WD2 / 1WD3 / 1WD4 / 13WG / 1WP.

-•Approximately 0.5 hour is required to remove and install a FDU.

4.2•DESCRIPTION

Within 1000 FH upon receipt of this AOT, apply the following instructions:

4.2.1•Follow “JOB SET UP” steps of AMM Tasks Ref. 1 to 4 as applicable for

removal of FDU 1WD1, 1WD2, 1WD3, 1WD4, 13WG and 1WP.

4.2.2•Visually identify FDU P/N and S/N for position 1WD1 and 1WD2 and 1WD3

and 1WD4 and 13WG and 1WP.

Note: a review of aircraft maintenance records is acceptable in lieu

of the visual inspection if P/N and S/N of the installed FDU can be

conclusively identified from that review.

4.2.3•Compare FDU P/N and S/N to the list of suspect units provided in

paragraph 3.4 of this AOT.

4.2.4•If listed in paragraph 3.4 of this AOT, no later than 1000 FH upon

receipt of this AOT, remove and replace the FDU as per the applicable

Ref. 1 to 8 AMM task.

4.3•MATERIAL INFORMATION

4.3.1•Material – Price and availability

Upon receipt of a free of charge purchase order, L’HOTELLIER will provide

FDU free of charge to replace suspect units. For more details and

logistics, please contact L’HOTELLIER focal point:
Ms. Catherine Bassin

Repair Assistant

Tel: 33 (0) 1.55.59.09.72

Fax: 33 (0) 1.46.66.66.71

Email: Catherine.Bassin@hs.utc.com

4.3.2• Tooling

Not applicable.

5.•FURTHER ACTION

L’HOTELLIER will rework the suspect FDUs. Rework will be identified with a

letter “R” added to the serial number on the FDU identification plate. The

FDUs listed in paragraph 3.4 of this AOT that are marked with serial number

followed by “R” letter are no longer concerned by this AOT.

6.•AOT APPROVAL

The technical content of this AOT has been approved under the authority of

EASA design organization approval number EASA 21J.031.

It is expected that the content of this AOT will be rendered mandatory by

the Airworthiness Authorities.

7.•REPORTING/ACKNOWLEDGMENT

Operators are requested to acknowledge receipt of this AOT within 48 hours

after receipt to:

Ms. E. GAILLANOU, SEEE,

E-mail: emilie.gaillanou@airbus.com

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

This acknowledgement can be made through the Airbus FSR when available.

Results or questions about the technical content of this AOT are to be

addressed to:

Mr. Jerome Real

Pneumatics, Ice and Fire Protection (SEEE4)

Phone: +33 (0)5 61 93 71 85

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

mailto: jerome.real@airbus.com

Best regards,

P.GOURDON

VICE PRESIDENT A330 / A340 PROGRAM

CUSTOMER SERVICES DIRECTORATE

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