COMMONWEALTH OF AUSTRALIA (Civil Aviation Regulations 1998), PART 39 - 106 CIVIL AVIATION SAFETY AUTHORITY SCHEDULE OF AIRWORTHINESS DIRECTIVES AlliedSignal (Lycoming) Turbine Engines - T53 Series AD/T53/18 Gas Producer and Power Turbine Discs and Spacers Applicability: T5313B turboshaft engines. 9/87 DM Requirement: Remove from service: GPT disc P/N 1-100-133-01, PT disc P/N 1-140-272-01, GPT spacer P/N 1-100-294-03, PT spacer P/N 1-140-169-03, and PT spacer P/N 1- 140-169-04 in accordance with FAA AD 87-12-05 Amdt 39-5640. Note: Lycoming SB No. 0020 Revision 2 dated 3 January 1986 refers (this is the Requirement Document of AD/T53/1 Amdt 1). Compliance: Unless already accomplished; in accordance with the schedules detailed in FAA AD 87-12-05 Paras (a) to (e) with effect from 20 July 1987. Background: The service cyclic life for the GPT disc and the PT second stage disc has been reduced and a cyclic life limit established for GPT and PT spacers. This Directive is issued to assure the timely removal from service of affected components to prevent uncontained engine failures.