AD FAA-2015-0266

We are adopting a new airworthiness directive (AD) for all Pratt & Whitney Division (PW) PW6122A and PW6124A turbofan engines. This AD requires initial and repetitive borescope inspections (BSIs) of the high-pressure compressor (HPC) 7th stage integrally bladed (IB) rotor aft integral arm for cracks until replacement of the HPC 7th stage IB rotor using non-silver-plated nuts. This AD was prompted by reports of crack finds in the HPC 7th stage IB rotor. We are issuing this AD to prevent HPC 7th stage IB rotor fractures, which could lead to uncontained engine failure and damage to the airplane.