AD/DHC-1/33 Amdt 2 Tailplane Support Struts (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-1/33 Amdt 1 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-1/33 Amdt 2 Tailplane Support Struts 13/2011

Applicability:

English production (C1), all models, and Portuguese (T Mk 20) production models.

Requirement:

Action in accordance with British Aerospace Mandatory TNS CT(C1) 186 issue 2.

Compliance:

1.    Unless already accomplished in accordance with the initial issue of this Directive and holding a BAe radiographic acceptable assessment from that inspection; within three months after the effective date of this AD or prior to CofA issue, whichever occurs first.

2.    Repeat inspections at periods not exceeding seven years after:

a.     the installation of new struts, or

b.    compliance with either the initial issue or this amendment of this Directive.

Note:  Compliance date for the initial issue of this Directive was 20 November 1992.  This AD also applies to any struts held as spares.

This Amendment becomes effective on 22 June 2011.

Background:

A case of internal corrosion in a tailplane attachment strut was reported.  The initial issue of the Directive required an external visual inspection, rework and NDI.  Amendment 1 introduced a repeat inspection, and revised and clarified the technical requirements via the TNS.

This amendment adds the Portuguese manufactured T Mk 20 to the applicability of this Airworthiness Directive.  A review of documentation indicates that this inspection is applicable to any aircraft with P/N C1-T-5A tailplane support struts, which may be fitted to both the English and Portuguese produced models.  However, the tailplane support strut part number should be checked to determine the applicability of this AD to your particular aircraft.  Contact the manufacturer or TC holder for further information on applicability of this inspection to your particular aircraft if there is any doubt.

There is no change to the requirements and the compliance wording has been clarified, but inspection interval is unchanged.

Glen Steemson
Delegate of the Civil Aviation Safety Authority

16 June 2011