Airworthiness Directives; Rolls-Royce plc RB211 Turbofan Engines

This amendment adopts a new airworthiness directive (AD), that is applicable to Rolls-Royce plc model RB211-535E4-37, RB211-535E4-B- 37, RB211-535C-37, RB211-535E4-B-75 and RB211-22B-02 turbofan engines. This amendment requires inspection of certain high pressure (HP) turbine disks, manufactured between 1989 and 1999, for cracks in the rim cooling air holes, and, if necessary, replacement with serviceable parts. This amendment is prompted by reports of cracks in two high life Trent 800 disk rim cooling air holes produced at the same manufacturing facility using the same tooling as the RB211 turbofan engine HP turbine disks. The actions specified by this AD are intended to prevent possible disk failure, which could result in an uncontained engine failure and damage to the aircraft.