Airworthiness Directives; Pratt & Whitney PW4000 Series Turbofan Engines

This amendment adopts a new airworthiness directive (AD) that is applicable to certain Pratt & Whitney (PW) PW4000 series turbofan engines that are equipped with the high pressure compressor (HPC) cutback stator (CBS) configuration and that are used on Boeing 747, Boeing 767, and McDonnell Douglas MD-11 series airplanes. This action requires Operators to limit the number of engines with the HPC CBS configuration to one per airplane, and prohibits installation of engines with HPC modules modified after the effective date of this AD to incorporate the HPC CBS configuration. This amendment is prompted by reports of HPC surges in engines that have the HPC CBS configuration. The actions specified in this AD are intended to prevent a multiple- engine power loss due to HPC surges, which could result in engine power loss at a critical phase of flight such as takeoff or climb.