Airworthiness Directives; Pratt & Whitney Canada PW206A and PW206E Turboshaft Engines

The FAA is adopting a new airworthiness directive (AD) for Pratt & Whitney Canada (PWC) PW206A and PW206E turboshaft engines. This AD requires initial and repetitive borescope inspections of compressor turbine and power turbine blades for blade axial shift, and replacement of blade retaining rivets and certain rotor air seals as terminating action for the repetitive borescope inspections. This AD is prompted by reports of engine shutdowns and emergency landings due to severe vibration and drops in engine torque, and an increase in internal engine temperature, triggering in-flight engine fire warnings. We are issuing this AD to prevent turbine blade axial shift, which could cause high levels of vibration, loss of engine torque, in-flight engine shutdown, and possible uncontained engine failure.