Airworthiness Directives; Rolls-Royce Corporation (RRC) AE 3007A Series Turbofan Engines

This document publishes in the Federal Register an amendment adopting emergency airworthiness directive (AD) 2009-08-51 that was sent previously to all known U.S. owners and operators of RRC AE 3007A series turbofan engines. This AD requires performing an eddy current inspection (ECI) or surface wave ultrasonic test (SWUT) inspection on each affected high-pressure turbine wheel. This AD results from additional reports of cracks in the high-pressure turbine (HPT) stage 2 wheels identified from the required inspections in AD 2008-26-06. A revised risk assessment that includes these additional reports indicates we need to require a higher inspection rate. We are issuing this AD to prevent an uncontained failure of the HPT stage 2 wheel and damage to the airplane.