Airworthiness Directives; Lycoming Engines (Formerly Textron Lycoming) AEIO-360, IO-360, O-360, LIO-360, LO-360, AEIO-540, IO-540, O-540, and TIO-540 Series Reciprocating Engines

The FAA is adopting a new airworthiness directive (AD) for certain Lycoming Engines (formerly Textron Lycoming) AEIO-360, IO-360, O-360, LIO-360, LO-360, AEIO-540, IO-540, O-540, and TIO-540 series reciprocating engines rated at 300 horsepower (HP) or lower. This AD requires replacing certain crankshafts. This AD results from reports of 12 crankshaft failures in Lycoming 360 and 540 series engines rated at 300 HP or lower. We are issuing this AD to prevent failure of the crankshaft, which could result in total engine power loss, in-flight engine failure, and possible loss of the aircraft.