Ad/BAe 146/137 Amdt 1 - Nose Landing Gear (Cth)

AIRWORTHINESS DIRECTIVE

On the effective date specified below, and for the reasons set out in the background section, the CASA delegate whose signature appears below revokes Airworthiness Directive (AD) AD/BAe 146/137 and issues the following AD under subregulation 39.001(1) of CASR 1998.  The AD requires that the action set out in the requirement section (being action that the delegate considers necessary to correct the unsafe condition) be taken in relation to the aircraft or aeronautical product mentioned in the applicability section: (a) in the circumstances mentioned in the requirement section; and (b) in accordance with the instructions set out in the requirement section; and (c) at the time mentioned in the compliance section.

British Aerospace BAe 146 Series Aeroplanes

AD/BAe 146/137 Amdt 1 Nose Landing Gear 11/2009 TX

Applicability:

All Model BAe 146 and AVRO 146-RJ aircraft, all serial numbers, if a Messier-Dowty Nose Landing Gear (NLG) unit with part number 200876001, 200876002, 200876003, 200876004, or 201138002 is installed, on which Messier-Dowty SB
146-32-150 has not been embodied, or if a Messier-Dowty NLG unit with one of these part numbers is installed, which has had Messier-Dowty SB 146-32-150 declared as being embodied by Messier Services, Sterling, Virginia, United States of America.

Note:  Aircraft with a NLG unit part number 201138002 installed having serial number M-DG-0169 or higher are not affected by this Directive.

Requirement:

Action in accordance with the requirements of EASA AD 2009-0197-E.

Note:  BAE Systems (Operations) Limited Alert ISB A32-180 Revision 1, or later EASA approved revision, refers.

Compliance:

As specified in the Requirement.

This Amendment becomes effective on 7 September 2009.

Background:

A crack detected at the top of an NLG oleo in June 2000 prompted BAE Systems to issue Inspection Service Bulletin (ISB) 32-158, which was classified mandatory by the UK CAA.  Optional terminating action for the NDT inspections was provided by incorporation of Messier-Dowty Service Bulletin (SB) 146-32-150.  As part of a recent accident investigation, the examination of a fractured NLG main fitting showed that SB 146-32-150 had not been incorporated, although the records indicated that it had been.  BAE Systems has determined that more NLG units could be similarly affected that have been overhauled at the same facility.

Amendment 1 is issued in response to a new EASA AD, which was prompted by subsequent investigation and analysis by Messier-Dowty that identified the need for a reduction of the inspection threshold and the repetitive inspection interval for the affected NLG units; and has replaced Messier-Dowty SB 32-149 with SB
146-32-174. Consequently, BAE Systems SB 32-158 has been withdrawn and superseded by BAE Systems Alert ISB A32-180 Revision 1.

David Villiers
Delegate of the Civil Aviation Safety Authority

4 September 2009