Airworthiness Directives; Rolls-Royce plc RB211 Series Turbofan Engines

This amendment supersedes an existing airworthiness directive (AD) applicable to certain Rolls-Royce plc (R-R) RB211 series turbofan engines. That AD currently requires the removal from service of intermediate pressure (IP) compressor stage 6-7 rotor shafts that exceed reduced cyclic life limits. This amendment requires further reduction of cyclic life limits and introduction of new reduced cyclic bands for rework. This action is prompted by additional stress analysis conducted following failure of an IP compressor stage 6 disk. The actions specified by this AD are intended to prevent an uncontained engine failure due to rupture of an IP compressor stage 6-7 rotor shaft.