COMMONWEALTH OF AUSTRALIA (Civil Aviation Regulations 1998), PART 39 - 106 CIVIL AVIATION SAFETY AUTHORITY SCHEDULE OF AIRWORTHINESS DIRECTIVES Pratt and Whitney Turbine Engines - JT8D Series AD/JT8D/36 Compressor Disks 2/99 Applicability: Pratt and Whitney JT8D series engines that have a compressor disk installed identified by part and serial number in Table 1 of FAA AD 98-21-24. Requirement: Inspect affected compressor disks in accordance with the technical requirements of FAA AD 98-21-24. Note: GE Engine Services - Dallas, LP, Engineering Bulletin (EB) JT8D-025, dated 27 March 1998 also refers. Compliance: At the next shop visit, or within 3000 cycles in service after the effective date of this Directive, or within 10 years after the effective date of this Directive, whichever occurs first. This Airworthiness Directive becomes effective on 25 February 1999. Background: This airworthiness directive is prompted by reports of improper fixturing during the electrolytic cleaning of certain compressor discs that can result in arc burns in disk tiebolt holes, pressure balance holes and shielding holes. Arc burns in these areas could lead to a disk fracture and uncontained engine failure.