Airworthiness Directives; Rolls-Royce plc Tay 650-15 Series Turbofan Engines

This amendment adopts a new airworthiness directive (AD) that is applicable to Rolls-Royce plc Tay 650-15 series turbofan engines. This AD requires the establishment of cyclic life limits for stage 1 high pressure turbine (HPT) and stage 1 low pressure turbine (LPT) disks operating under new flight plan profiles. This amendment is prompted by reports that, on some engines, cracks in the stage 1 HPT and stage 1 LPT disks could initiate and propagate at a faster rate than forecast under the flight plan profiles originally published at the time the engine design was certified. The actions specified by this AD are intended to prevent crack initiation and propagation leading to turbine disk failure, which could result in an uncontained engine failure and damage to the aircraft.