AD/BAe 146/118 Left Control Cable Duct at Frame 12 and Toilet Bulkhead Structure (Cth)

AIRWORTHINESS DIRECTIVE

For the reasons set out in the background section, the CASA delegate whose signature appears below issues the following Airworthiness Directive (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 146/118 Left Control Cable Duct at Frame 12
and Toilet Bulkhead Structure 13/2005

Applicability:

All Models BAe 146 and AVRO 146-RJ series aircraft with Service Bulletin
25-436-50303C installed.

Requirement:

1.    For aircraft with Service Bulletin 25-436-50303C installed:

Carry out the modification to the control cable duct in accordance with Paragraph 2, Part 1 of Service Bulletin 25-459-36241A initial issue, or later EASA approved revision.

2.    For aircraft with Service Bulletin 25-436-50303C installed and which also have a toilet unit installed under modification HCM30033E or HCM30033F or HCM30033G or HCM30033N at the forward left position:

Carry out the modifications to the control cable duct and toilet bulkhead structure in accordance with Paragraph 2, Part 1 and Part 2 of Service Bulletin
25-459-36241A initial issue, or later EASA approved revision.

Note:  UK CAA AD G-2005-0026 refers.

Compliance:

Before 30 June 2006.

This Airworthiness Directive becomes effective on 22 December 2005.

Background:

Under certain conditions, if a Windscreen A Panel were to fail causing a rapid decompression and the flight deck door were in a closed position, the resultant differential pressure between the flight deck and cabin could result in deformation of the flight deck bulkhead at Frame 12 and the cable duct attached to it.  This duct protects the primary flying control cables that run in this area and any deformation could result in the duct contacting these cables, leading to restriction of the primary flying controls.

David Villiers
Delegate of the Civil Aviation Safety Authority

8 November 2005