Airworthiness Directives; Pratt & Whitney Division (PW) PW4000 Series Turbofan Engines

摘要

We are adopting a new airworthiness directive (AD) for certain PW4000 turbofan engines. This AD was prompted by an updated low-cycle fatigue (LCF) life analysis performed by PW. This AD requires removing certain part number (P/N) high-pressure turbine (HPT) stage 1 and HPT stage 2 airseals and HPT stage 1 airseal rings before their published life limit and establishes a new lower life limit for these parts. We are issuing this AD to prevent failure of these parts, which could lead to an uncontained engine failure and damage to the airplane.