Airworthiness Directives; Pratt & Whitney PW4000 Series Turbofan Engines

The FAA is superseding an existing airworthiness directive (AD) for Pratt & Whitney (PW) PW4000 series turbofan engines. That AD currently requires revisions to the engine manufacturer's time limits section (TLS) to include enhanced inspection of selected critical life- limited parts at each piece-part opportunity. This AD modifies the airworthiness limitations section of the manufacturer's manuals and an air carrier's approved continuous airworthiness maintenance program by adding eddy current inspections for front compressor hubs installed in PW 4000-94" engine models. This AD also adds the PW4062A engine to the applicability. An FAA study of in-service events involving uncontained failures of critical rotating engine parts has indicated the need for mandatory inspections. The mandatory inspections are needed to identify those critical rotating parts with conditions, which if allowed to continue in service, could result in uncontained failures. 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.