AD 2014-17-08 79 FR 52172

We are adopting a new airworthiness directive (AD) for all Pratt & Whitney Canada Corp. (P&WC) PT6A-114 and PT6A-114A turboprop engines. This AD requires initial and repetitive borescope inspection (BSI) of compressor turbine (CT) blades, and the removal from service of blades that fail inspection. This AD was prompted by several incidents of CT blade failure, causing power loss, and engine failure. We are issuing this AD to prevent failure of CT blades, which could result in damage to the engine and damage to the airplane.