Airworthiness Directives; Lycoming Engines (L)O-360, (L)IO-360, AEIO-360, O-540, IO-540, AEIO-540, (L)TIO-540, IO-580, and IO-720 Series Reciprocating Engines

요약

We propose to supersede an existing airworthiness directive (AD) that applies to the products listed above. The existing AD currently requires replacing certain crankshafts. Since we issued that AD, Lycoming Engines discovered that the start date of affected engine models in Mandatory Service Bulletin (MSB) No. 569A, is incorrect. This proposed AD would correct that start date. We are proposing this AD to prevent failure of the crankshaft, which will result in total engine power loss, in-flight engine failure, and possible loss of the aircraft.