COMMONWEALTH OF AUSTRALIA (Civil Aviation Regulations 1998), PART 39 - 106 CIVIL AVIATION SAFETY AUTHORITY SCHEDULE OF AIRWORTHINESS DIRECTIVES AlliedSignal (Lycoming) Turbine Engines - ALF502 and LF507 Series AD/ALF/3 Compressor Housing Support Assembly 2-103-070-07 - Inspection and Replacement 1/86 Applicability: Lycoming model ALF 502L-2 turbofan engine S/Nos. LF03020, LF03021, LF03038, LF03039. Document: 1. Lycoming SB No. ALF 502-72-0014; or 2. AD/LYC-T/20. Compliance: 1. Immediately upon receipt of this Directive and after each 100 hours of engine operation thereafter until affected support assemblies are replaced. 2. Affected compressor housing support assemblies must be replaced not later than 800 hours or 600 cycles time in service whichever occurs first. Background: This Directive is issued as the result of notification from the engine manufacturer that the affected engines were installed with the rear engine mount improperly assembled. With this condition, normal flight loads may have imposed excessive stress on the compressor housing support assembly engine mounting lugs. Affected mounting lugs must be periodically inspected for possible cracks until compressor housing support assembly is replaced.