COMMONWEALTH OF AUSTRALIA (Civil Aviation Safety Regulations 1998), PART 39 - 106 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 revokes Airworthiness Directive (AD) AD/DART/23 and issues the following 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. Rolls Royce Turbine Engines - Dart Series AD/DART/23 Amdt 1 Low Pressure Turbine Disc 10/2003 Applicability: Dart 520, 525, 526, 527, 528, 529, 530, 531, 532, 533, 534, 535, 536, 542, 543, 550 and 552 series engines. Requirement: Action in accordance with Rolls Royce Alert Service Bulletin (ASB) Da72-A512. This Directive supersedes the requirements of AD/ENG/7 with respect to Low Pressure Turbine (LPT) disc lives for the applicable Rolls Royce Dart series engines. Compliance: As detailed in the Requirement document. This Amendment becomes effective on 2 October 2003. Background: The original issue of this Directive was raised to limit the cyclic lives of certain LPT discs following advice that four LPT disc failure events had occurred in-service between 1985 and 1989. This Amendment does not alter the technical requirements of this Directive but replaces reference to cancelled AD/DART/1 with AD/GEN/7 together with minor editorial changes. The original issue of this Airworthiness Directive became effective on 5 October 1989. Jim Coyne Delegate of the Civil Aviation Safety Authority 19 August 2003 The above AD is notified in the Commonwealth of Australia Gazette on 10 September 2003. Page 1 of 1