AIRWORTHINESS DIRECTIVE

Number: CAA-AD-052/2001

Date of issue: June 14, 2001

AIRCRAFT - PROPELLER FEATHERING - INSPECTION

Applicability: ATR 42-200, -300, -320, -400 and -500 aircraft models fitted with IPP JANCO ATPCS test selector switch P/N ACE 0002.

Effective date: August 09, 2001

Compliance: Required as indicated in DGAC AD 2001-214-084(B).

Remarks: The compliance of this AD must be recorded in Aircraft Logbook, where applicable the requirements of this AD must be integrated into Aircraft Technical Documentation. Address inquiries concerning this AD to: Civil Aviation Authority, Airworthiness Division, Ruzyne Airport, 160 08 Prague 6, Czech Republic, tel: 420 2 33320922, fax: 420 2 20562270.

Ing. Pavel MATOUŠEK

Director of Airworthiness Division

CAA CZ

DGAC AD No.: 2001-214-084(B)

EADS ATR

ATR 42 aircraft

Propeller feathering -ATPCS test selector switch (ATA 24, 61)

1. APPLICABILITY:

ATR 42-200, -300, -320, -400 and -500 aircraft models fitted with IPP JANCO ATPCS test selector switch P/N ACE 0002.

Note: The aircraft having received the embodiment of modification 5162 and on which no replacement of ATPCS test selector switch was performed afterwards, are not involved.

2. REASONS:

Several cases of dual engine power drop, during ground manoeuvres, with the associated loss of both ACW and main hydraulic power were reported on ATR aircraft fleet over the last two years. Investigation revealed abnormal wear of contact surfaces within the IPP JANCO ATPCS test selector switch P/N ACE 0002. The discovered wear is suspected to have caused a shorting of contacts and the subsequent NP cancels experienced. Each time, the ATPCS test selector switch replacement cleared the malfunction.

It has been determined that this failure mode can occur only in NP governing mode, during taxiing or landing, and neither during take-off, when power is applied, nor in flight, due to the different governing mode applicable during these operating phases

Nevertheless, this failure mode might contribute to increase the Bight crew workload during ground manoeuvres.

The actions made mandatory by this Airworthiness Directive (AD) are intended to prevent a dual engine power drop during ground manoeuvres which could result in reduced aircraft controllability.

3. ACTIONS:

The following measures are rendered mandatory on the effective date of this AD:

At the first opportunity and, at the latest within 5 years following the effective date of this AD, remove the IPP JANCO ATPCS test selector switch P/N ACE 0002 fitted on panel 114VU (FIN 22KF) and replace it by IEC Electronique test selector switch P/N 097-037-00.

From June 09, 2006, the IPP JANCO ATPCS test selector switch P/N ACE 0002 are prohibited in service and must be withdrawn from stock.

Note: ATR Illustrated Parts Catalogue (chapter 61-22-80) has been revised accordingly to cover P/N 097-037-00 as the only source for ATPCS test selector switch.

EFFECTIVE DATE: JUNE 09, 2001