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 39.001(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. General Electric Turbine Engines - CF6 Series AD/CF6/82 High Pressure Compressor Disk Lock Slots 21/2010 Applicability: General Electric Company CF6 engines as specified in FAA AD 2000-11-12. Requirement: Unless already accomplished, inspect in accordance with the requirements of FAA AD 2000-11-12. Repeat the inspections in accordance with the requirements of FAA AD 2000-11-12. Later revisions to Alert Service Bulletin GE CF6-50 ASB No. 72-A1144, Revision 1, dated May 13, 1999 that are approved by the United States Federal Aviation Administration (FAA) as an Alternate Method of Compliance (AMOC) to FAA AD 2000-11-12, are considered acceptable for compliance with the equivalent Requirements of this AD. Compliance: As specified in the Requirement Document with a revised effective date of 11 November 2010. This Airworthiness Directive becomes effective on 11 November 2010. Background: This AD is prompted by reports of stage 14 High Pressure Compressor (HPC) disk lock slot cracks discovered during shop fluorescent penetrant inspections. The actions specified in this AD are intended to prevent stage 14 HPC disc failure, which could result in an uncontained engine failure and damage to the aircraft. Mike Higgins Delegate of the Civil Aviation Safety Authority 15 October 2010