COMMONWEALTH OF AUSTRALIA (Civil Aviation Regulations 1998), PART 39 - 106 CIVIL AVIATION SAFETY AUTHORITY SCHEDULE OF AIRWORTHINESS DIRECTIVES Pratt and Whitney Turbine Engines - JT9D Series AD/JT9D/28 LPT Vane Hardware 1/97 Applicability: All Pratt and Whitney JT9D-7R4 series engines. Requirement: Replace certain 5th stage Low Pressure Turbine (LPT) vanes, and 3rd, 4th and 5th stage vane retention hardware in accordance with the technical requirements of FAA AD 96-17-11. Compliance: As detailed in the Requirement Document with an effective date of 2 January 1997. Background: There have been reports of failures of LPT vane retention hardware which resulted in uncontained engine failures.