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.
De Havilland DHC-1 (Chipmunk) Series Aeroplanes
AD/DHC-1/41
Fuselage Rear Bulkhead - Inspection
and Modification
16/2011
 
Applicability:
All DHC-1 Chipmunk aircraft.

Requirement:
Inspect and modify the fuselage rear bulkhead in accordance with the technical requirements of Transport Canada Airworthiness Directive CF-52-06.
Note:  De Havilland Aircraft of Canada Limited Technical News Sheet C-33 refers.

Compliance:
As stated in the requirement document unless reinforcing modification is incorporated.

 
This Airworthiness Directive becomes effective on 12 August 2011.

Background:
Cracking of the stiffener part No. 084 has been reported.  Repetitive inspections are prescribed through the port and starboard fairings at the base of the rudder post.  Modification by installing reinforcing plates on the bulkhead stiffener terminates repetitive inspection requirements.

Charles Lenarcic
Delegate of the Civil Aviation Safety Authority
5 August 2011