Airworthiness Directives; Teledyne Continental Motors GTSIO-520 Series Reciprocating Engines

The FAA is adopting a new airworthiness directive (AD) for Teledyne Continental Motors (TCM) GTSIO-520 series reciprocating engines. This AD requires initial and repetitive visual inspections of the starter adapter assembly and crankshaft gear. This AD also requires unscheduled visual inspections of the starter adapter assembly and crankshaft gear due to a rough-running engine. This AD also requires replacement of the starter adapter shaft gear needle bearing with a certain bushing. Also, this AD requires installation of a certain TCM service kit at the next engine overhaul, or at the next starter adapter replacement, whichever occurs first. This AD results from six service difficulty reports and one fatal accident report received related to failed starter adapter assemblies. We are issuing this AD to prevent failure of the starter adapter assembly and or crankshaft gear, resulting in failure of the engine and possible forced landing.