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

The FAA is superseding an existing airworthiness directive (AD) for Teledyne Continental Motors (TCM) GTSIO-520 series reciprocating engines. That AD currently requires initial and repetitive visual inspections of the starter adapter assembly and crankshaft gear and unscheduled visual inspections of the starter adapter assembly and crankshaft gear due to a rough-running engine. That AD also requires replacement of the starter adapter shaft gear needle bearing with a certain bushing and installation of a certain TCM service kit at the next engine overhaul, or at the next starter adapter replacement, whichever occurs first. This AD requires performing the inspection ordered in paragraph (h) of this AD every 100 hours time-in- service (TIS), or annually. This proposed AD results from an error discovered in AD 2005-20-04. We are issuing this AD to failure of the starter adapter assembly and or crankshaft gear, resulting in failure of the engine and possible forced landing.