AIRWORTHINESS DIRECTIVE For the reasons set out in the background section, the CASA delegate whose signature appears below revokes Airworthiness Directive (AD) AD/JT8D/12 Amdt 1 and issues the following 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. Pratt and Whitney Turbine Engines - JT8D Series AD/JT8D/12 Amdt 2 High Pressure Compressor Disc Tie Rod Hole 7/2005 Applicability: Pratt & Whitney (P&W) JT8D-1, -1A, -7, -7A, -7B, -9, -9A, -11, -15, -15A, -17, -17A, -17R, and -17AR turbofan engines. Requirement: Inspect 9th through 12th stage High Pressure Compressor (HPC) disks at the tie-rod holes in accordance with the Requirements of Federal Aviation Administration (FAA) Airworthiness Directive (AD) 95-16-07. Note: FAA AD 95-16-07 Amendment 39-9327 refers. Compliance: Unless previously accomplished, as per compliance schedule of the FAA AD 95-16-07. This Amendment becomes effective on 7 July 2005. Background: There have been reports of uncontained failure of 9th through 12th HPC discs because of the cracks originating from tie-rod holes. The inspection requirements of this AD are aimed at detection of cracks and prevention of resultant uncontained failures. The current amendment deletes reference to the manufacturer's document and refers to the FAA AD as part of the harmonisation with the engine certificating Authority requirements. Amendment 1 of this Directive became effective in 1987. James Coyne Delegate of the Civil Aviation Safety Authority 25 May 2005