AD/DHC-1/36 Amdt 1 Flap Operating Cables (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/DHC-1/36 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.

De Havilland DHC-1 (Chipmunk) Series Aeroplanes

AD/DHC-1/36 Amdt 1 Flap Operating Cables 9/2007

Applicability:

English-built DHC-1 Chipmunk aircraft, all marks.

Requirement:

Action in accordance with De Havilland Support Ltd TNS CT(C1) No.184 Issue 4.

Note:  UK CAA AD 001-03-95 refers.

Compliance:

At intervals not to exceed 150 flight hours or at the Annual Inspection, whichever occurs first.

This Amendment becomes effective on 30 August 2007.

Background:

Cases have been reported of failure of the flap operating cable which in one case led to a flap asymmetry situation during the final phase of landing.  Investigation has shown the failures were due to either incorrect rigging of the control cables or inadequate maintenance of the control pulleys.

Amendment 1 is issued in response to the latest issue of the Requirement document, which introduces a repetitive inspection of the latch plate and flap lever quadrant for wear.

David Villiers
Delegate of the Civil Aviation Safety Authority

20 July 2007