AD/BAe 146/139 Aileron Interconnect Cable Pulley Guards (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 146/139 Aileron Interconnect Cable Pulley Guards 21/2009

Applicability:

All Model BAe 146 and AVRO 146-RJ aircraft, all serial numbers.

Requirement:

Action in accordance with the requirements of EASA AD 2009-0205.

Note:  BAE Systems (Operations) Ltd Service Bulletin SB.27-183-36246A dated
9 December 2008, or later EASA approved revision, refers.

Compliance:

As specified in the Requirement document.

This Airworthiness Directive becomes effective on 14 October 2009.

Background:

Three events have been reported where insulation material was found to be fouling pulleys in the aileron interconnect circuit in the cabin roof area.  The insulation material is contained in a bag, the material of which tends to become brittle with age.  Interference between the cable and the insulation bag causes the material to be drawn into the gap between the pulley and the pulley guard.  This condition, if not detected and corrected, could lead to restricted aileron movement and consequent reduced control of the aircraft.

David Villiers
Delegate of the Civil Aviation Safety Authority

7 October 2009