COMMONWEALTH OF AUSTRALIA (Civil Aviation 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 CAR 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. Bombardier (Boeing Canada/De Havilland) DHC-8 Series Aeroplanes AD/DHC-8/81 PCU Oil Pump 9/2001 Applicability: DHC-8 series 100, 200 and 300 aircraft, S/Nos 003 to 554 inclusive, not incorporating a back up pressure regulating valve per Bombardier Service Bulletin 8-61-31. Requirement: Incorporate a back up pressure regulating valve between the engine reduction gearbox and the auxiliary feather pump on both engines in accordance with Bombardier Service Bulletin 8-61-31. Note: Transport Canada AD CF-2001-12 refers. Compliance: At next scheduled engine shop visit after the effective date of this Airworthiness Directive but no later than 12 March 2003. This Airworthiness Directive becomes effective on 6 September 2001. Background: Incidents have occurred where failure of the oil pressure regulating valve in the PCU oil pump has caused excessive pressure build up resulting in fracture of the pump body, loss of engine oil and inability to feather the propeller. Eugene Paul Holzapfel Delegate of the Civil Aviation Safety Authority 26 July 2001 The above AD is notified in the Commonwealth of Australia Gazette on 15 August 2001. Page 1 of 1