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 issues the following Airworthiness Directive (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. Alliedsignal (Garrett/Airesearch) Turbine Engines - TFE 731 Series AD/TFE731/31 HP Compressor Impeller 4/2001 Applicability: TFE731 engines detailed by model in Honeywell Alert Service Bulletin TFE731- A72-3641 Revision 2 incorporating a high pressure compressor (HPC) impeller part number (P/N) 3073393-1, 3073394-1, 3073433-1, 3073434-1, 3073398-All, 3073435-All, 3075171-All, 3075765-1, 3075768-1 and 3075769-1. Requirement: Remove and inspect applicable HPC impeller in accordance with Honeywell Alert Service Bulletin TFE731-A72-3641 Revision 2. Note: FAA AD 2000-15-09 refers. Compliance: 1. From the effective date of this Directive; at the next compressor zone inspection or access to the HPC module, whichever occurs first, and 2. Thereafter at each compressor zone inspection, or 3. At next access to the HPC module if the HPC impeller has accumulated more than 1,000 cycles since last eddy current inspection (ECI). This Airworthiness Directive becomes effective on 19 April 2001. Background: This Directive has been issued to require removal and inspection of certain HPC impellers by part number. The FAA has determined that low cycle fatigue cracking in the high stress areas of the impeller may led to an uncontained impeller separation. Eugene Paul Holzapfel Delegate of the Civil Aviation Safety Authority 8 March 2001 The above AD is notified in the Commonwealth of Australia Gazette on 21 March 2001. Page 1 of 1