Airworthiness Directives; Rolls-Royce plc Turbofan Engines

We are adopting a new airworthiness directive (AD) for all Rolls-Royce plc (RR) RB211-535E4-37, RB211-535E4-B-37, and RB211-535E4- C-37 turbofan engines. This AD requires recalculating the cyclic life for certain engine life-limited rotating parts and removing those parts that have exceeded their cyclic life limit within specified compliance times. This AD was prompted by a review of operational data that determined certain RR RB211-535E4-37 engines have been operated to a more severe flight profile than is consistent with the flight profile used to establish the cyclic life limits for the rotating parts. We are issuing this AD to prevent failure of life-limited rotating parts, uncontained parts release, damage to the engine, and damage to the airplane.