COMMONWEALTH OF AUSTRALIA (Civil Aviation Regulations 1998), PART 39 - 106 CIVIL AVIATION SAFETY AUTHORITY SCHEDULE OF AIRWORTHINESS DIRECTIVES Pratt and Whitney Canada Turbine Engines - PT6A Series AD/PT6A/18 No. 2 Bearing Oil Pressure Tube 10/85 Applicability: PT6A-38, PT6A-41, PT6A-45A engines with S/Nos. as specified in the requirement document. Document: 1. Pratt & Whitney of Canada SB No. 3099, Rev. 2; or 2. AD/UAC-T/28A. Compliance: Within 100 hours time in service after 28 February, 1978. Background: This Directive is reissued in order to reflect the manufacturers latest reference document which completes the listing of engine serial numbers affected and clarifies new part assembly instructions.