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/23 Amdt 2 First Stage Fan Blade Retention Plate 8/90 Applicability: JT8D-9, -11, -15, -17 series engines. Requirement: Install a P/N 803996 or 808145 first stage fan blade retention plate. Note: FAA AD 89-25-11 refers. Compliance: At next access when parts are available, but no later than 31 December 1991. Background: This Directive has been amended to reflect the PWA release of an additional improved fan blade retention plate. Plate P/N 808145 incorporates the improved fan blade retention features of the P/N 803996 plate and incorporates non chamfered counterweight rivet holes as requested by certain JT8D operators. The P/N 803996 plate has chamfered counterweight rivet holes.