A new Airworthiness Directive (AD) will require initial and repetitive borescope inspections of some 300 PT6A engines and potentially cost operators as much as $18,106,200. Following reports of compressor turbine (CT) blade failures causing engine power loss, the FAA issued an AD Wednesday that requires replacement of blades that fail inspection with a newly developed blade. The purpose of the AD is to prevent failure of CT blades, which the FAA said "could result in damage to the engine and damage to the airplane." It becomes effective Oct. 8. Affected engines are Pratt & Whitney Canada (P & W) PT6A-114 and PT6A-114A engines.
This is a companion discussion topic for the original entry at https://www.avweb.com/ownership/potentially-expensive-new-ad-for-pt6-engines