COMMONWEALTH OF AUSTRALIA (Civil Aviation Regulations 1998), PART 39 - 106 CIVIL AVIATION SAFETY AUTHORITY SCHEDULE OF AIRWORTHINESS DIRECTIVES Lycoming Piston Engines AD/LYC/81 Amdt 3 Oil Pump Impellers 3/95 Applicability: All Lycoming piston engines other than; dual magneto 540 wide deck series engines built with high capacity oil pumps and O-320-H2AD, O-360-E1A6D, LO-360- E1A6D, TO-360-E1A6D and LTO-360-E1A6D 76 series engines. Requirement: Replace scintered iron oil pump impellers in accordance with Textron Lycoming Service Bulletin No. 456F. Compliance: Effective 2 March 1995: Unless previously accomplished in accordance with a previous issue of SB 456; 1. At next engine overhaul, bulk strip or 31 December 1995, whichever occurs first. 2. Prior to installation in an aircraft. 3. Prior to issue of an Australian Certificate of Airworthiness. Note: Previous compliance with the requirements of this Directive can be established by a review of the engine log books and/or engine records. Background: This Directive requires the replacement of sintered iron oil pump impellers in certain Lycoming engines. This amendment has been issued to reflect industry advice that the 76 series engines have a different oil pump and are therefore, not applicable. The amendment also includes a sunset clause in the compliance requirements. The change to the compliance requirements reflects advice of a recent major engine failure in a Cessna 172M/O-320-E2D. The engine had been last overhauled in the USA in 1986 and an investigation of the oil system related failure revealed sintered iron oil pump impellers were fitted.