COMMONWEALTH OF AUSTRALIA (Civil Aviation Regulations 1998), PART 39 - 106 CIVIL AVIATION SAFETY AUTHORITY SCHEDULE OF AIRWORTHINESS DIRECTIVES Rolls Royce Turbine Engines - RB211 Series AIRWORTHINESS DIRECTIVE For the reasons set out in the background section, the CASA delegate whose signature appears below revokes Airworthiness Directive (AD) AD/RB211/24 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. AD/RB211/24 Amdt 1 HP Turbine Disc - Inspection 3/2001 Applicability: RB211-535 engines as detailed in Rolls Royce Service Bulletin RB.211-72-C817 Revision 2. Requirement: Inspect high pressure turbine (HPT) discs in accordance with Rolls Royce Service Bulletin RB.211-72-C817 Revision 2. Note: UK CAA AD 003-12-99 refers. Compliance: As detailed in the requirement document. This amendment becomes effective on 22 March 2001. Background: This Directive was raised to mandate a mid life eddy current inspection of suspect HP turbine discs to detect possible machining faults in the disc air cooling holes. This amendment reflects the manufacturer's latest revision to the Requirement document. The revision, in part, reduces the compliance time for inspection and increases the number of discs affected to all discs manufactured between 1989 and 1999. The revision also responds to evidence of disc cooling air holes having been damaged by inappropriate cleaning during overhaul. The original issue of this Airworthiness Directive became effective on 10 August 2000. Eugene Paul Holzapfel Delegate of the Civil Aviation Safety Authority 9 February 2001 The above AD is notified in the Commonwealth of Australia Gazette on 21 February 2001.