COMMONWEALTH OF AUSTRALIA (Civil Aviation Safety Regulations 1998), PART 39 - 105 CIVIL AVIATION SAFETY AUTHORITY SCHEDULE OF AIRWORTHINESS DIRECTIVES 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 39.1 (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. DHC-2 (Beaver) Series Aeroplanes AD/DHC-2/33 Exhaust Collector Ring Segments 7/2003 Applicability: All Bombardier Inc. DHC-2 Mk. 1 aeroplanes. Requirement: 1. Remove the carburettor heater muff, part number (P/N) C2-EE-181A, -161A, - 171A, and -1155A and inspect the exhaust collector ring segments, P/N C2- EE251A, -253A, -255A, and -257A, for cracks or burnt holes. 2. Replace segments that have developed major breaks, cracks other than minor, or burning. 3. Segments with minor cracks must either be replaced or repaired by welding as per DHC-2 Beaver Maintenance Manual Para. 5.4.3, and DHC-2 Beaver Repair Manual Para. 6-13. 4. Replace segments that have developed further cracking from repair welds. Note: Transport Canada AD CF-2002-49 refers. Compliance: 1. Within 150 flight hours from the effective date of this directive and thereafter at intervals not to exceed 150 flight hours. 2, 3 and 4. Before further flight. This Airworthiness Directive becomes effective on 10 July 2003. Background: To prevent the possibility of a carburettor fire upon starting, particularly when the hot air valve control is in the "hot" position, this Directive requires a 150- hour repetitive inspection on exhaust collector ring segments to verify their integrity. Jim Coyne Delegate of the Civil Aviation Safety Authority 28 May 2003 The above AD is notified in the Commonwealth of Australia Gazette on 18 June 2003. Page 1 of 1