AD/DHC-8/108 Horizontal Stabiliser Attachment Fittings (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.

Bombardier (Boeing Canada/De Havilland) DHC-8 Series Aeroplanes

AD/DHC-8/108 Horizontal Stabiliser Attachment Fittings 3/2006

Applicability:

Model DHC-8-400, DHC-8-401, and DHC-8-402 aircraft, serial numbers 4001, and 4003 through 4081.

Requirement:

Action in accordance with the requirements of Transport Canada AD CF-2005-07.

Note:  Bombardier Service Bulletin 84-55-02 Revision A, or later Transport Canada approved revision, refers.

Compliance:

As specified in the Requirement document, with a revised effective date of
16 March 2006.

This Airworthiness Directive becomes effective on 16 March 2006.

Background:

The manufacturer received reports of delamination and extrusion of laminated shims from the interface of the horizontal stabiliser attachment fittings.  In addition, during removal of the horizontal stabiliser for replacement of the laminated shims with solid shims, it was discovered that the torque values of some bolts at the attachment locations on some aircraft were inconsistent with maintenance manual requirements.  This condition, unless corrected, could lead to a reduction in the fatigue life of the bolts, and consequent reduction of structural integrity of the horizontal stabiliser attachment.

David Villiers
Delegate of the Civil Aviation Safety Authority

3 February 2006