COMMONWEALTH OF AUSTRALIA (Civil Aviation 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/PW4000/7 and issues the following 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. Pratt & Whitney Turbine Engines - PW4000 Series AD/PW4000/7 Amdt 1 Low Pressure Turbine Fourth Stage Airseal 11/2001 DM Applicability: PW4000 series engines incorporating low pressure turbine 4th stage airseal, P/No 50N478 or 50N478-001. Requirement: Replace low pressure turbine 4th stage airseals, P/No 50N478 or 50N478-001 in accordance with the technical requirements of FAA AD 2001-05-07. Compliance: Comply with the requirements of this airworthiness directive at the periods specified in FAA AD 2001-05-07. Note: FAA AD 2001-05-07 supersedes FAA AD 2000-25-06. This Amendment becomes effective on 3 October 2001. Background: This Airworthiness Directive is prompted by reports of cracked low pressure turbine 4th stage airseals. Seal fracture could result in an uncontained engine failure leading to damage to the aircraft. This amendment references new FAA AD 2001-05-07 which supersedes FAA AD 2000-25-06 to correct an error relating to engines affected by P7W SB PW4 ENG 72- 657, Revision 1. The original issue of this Airworthiness Directive became effective 31 January 2001. Eugene Paul Holzapfel Delegate of the Civil Aviation Safety Authority 24 September 2001 The above AD is notified in the Commonwealth of Australia Gazette on 3 October 2001. Page 1 of 1