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-1/3 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-1/3 Amdt 1
Fuel Line Cock to Filter - Replacement
12/2011
 
Applicability:
English production (C1) all models and Portuguese (T Mk 20) production models.

Requirement:
Accomplish modification per De Havilland modification document H-188, latest revision.
Note 1:  De Havilland TNS No. 111 dated 3 August 1955 refers.  As stated in this TNS, operators should check the aircraft modification records to determine if this modification has already been incorporated.
Note 2:  Advice should be sought from De Havilland support if there is any doubt as to this modifications applicability to their particular aircraft.

Compliance:
Unless previously accomplished, prior to further flight.

 
This Amendment becomes effective on 21 June 2011.

Background:
This modification introduces a fuel feed pipe that is manufactured from tungum instead of aluminium between the fuel cock and fuel filter.  This was due to the fracture of an aluminium fuel feed pipe part number C1-P-45.
This modification was introduced in 1955, and up until now, Australia has had no Portuguese manufactured Chipmunks on the register, hence the CASA AD has only been effective for English production Chipmunks.  This amendment is to include the Portuguese manufactured Chipmunk in the applicability for this AD, as a recent check of the De Havilland support modification listing, shows that this modification is also applicable to the Portuguese model (T Mk 20).
There are no technical changes to the requirements or compliance of this AD.

 
 
 
 
 
 
The original issue of this AD became effective in June 1955.

Glen Steemson
Delegate of the Civil Aviation Safety Authority
14 June 2011