Airworthiness Directives; Pratt & Whitney Turbofan Engines

We are superseding an existing airworthiness directive (AD) for all Pratt & Whitney (PW) JT9D series turbofan engines. That AD currently requires revisions to the Airworthiness Limitations Section (ALS) of the manufacturer's Instructions for Continued Airworthiness (ICA) to include required enhanced inspection of selected critical life-limited parts at each piece-part opportunity. This new AD requires additional revisions to the JT9D series engines ALS sections of the manufacturer's ICA. This AD was prompted by the need to require enhanced inspection of selected critical life-limited parts of JT9D series engines. We are issuing this AD to prevent critical life-limited rotating engine part failure, which could result in an uncontained engine failure and damage to the airplane.