Airworthiness Directives; Lycoming Engines (Formerly Textron Lycoming), Direct-Drive Reciprocating Engines

The FAA is adopting a new airworthiness directive (AD) that supersedes an existing AD, for Lycoming Engines (formerly Textron Lycoming), direct-drive reciprocating engines (except O-145, O-320H, O- 360E, LO-360E, LTO-360E, O-435, and TIO-541 series engines). That AD currently requires inspection of the crankshaft gear installation and rework or replacement of the gears where necessary after a propeller strike, sudden stoppage, at overhaul, or whenever gear train repair is required. This AD requires the same actions but makes the correction that the existing gear retaining bolt and lockplate be removed from service and new hardware installed, and revises the definitions for sudden stoppage and propeller strike. This AD results from a change to the definition of a propeller strike or sudden stoppage. We are issuing this AD to prevent loosening or failure of the crankshaft gear retaining bolt, which may cause sudden engine failure.