AD/DH 89/4 Streamline Wires (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.

DH 89 (Dragon Rapide) Series Aeroplanes

AD/DH 89/4 Streamline Wires 13/2005 DM

Applicability:

Model DH89A (All Series) aircraft, fitted with stainless steel streamline wires manufactured by Bruntons Aero Products Ltd or its predecessor companies.

Requirement:

Inspect, and where required, replace the stainless steel streamline wires in accordance with de Havilland Support Ltd TNS CT(89) No. 37 Issue 1, or later CAA approved revision.

The results of all inspections conducted must be reported to de Havilland Support Ltd in accordance with paragraph 3c of the Requirement document.

Note:  UK CAA AD G-2005-0033 refers.

Compliance:

Before 31 December 2005.

This Airworthiness Directive becomes effective on 9 November 2005.

Background:

Two in-flight fractures of stainless steel streamline wire wing bracing are known to have occurred to single engine de Havilland biplanes since 2001.  Fracture of one or more stainless steel streamline wires will likewise compromise structural integrity of a twin engine de Havilland aircraft.  Inspection of the streamline wires is required to minimise the risk of further in-flight fractures and, in combination with a parallel exercise on Moth aircraft, to establish the magnitude of any fleet wide safety issue.

David Villiers
Delegate of the Civil Aviation Safety Authority

7 November 2005