Airworthiness Directives; Rolls-Royce plc RB211 Trent 800 Series Turbofan Engines

This amendment adopts a new airworthiness directive (AD) that applies to Rolls-Royce plc (RR) RB211 Trent 875-17, Trent 877-17, Trent 884-17, Trent 892-17, Trent 892B-17, and Trent 895-17 turbofan engines with high pressure (HP) compressor rotor rear stage 5 and 6 discs and cone shafts, part numbers (P/Ns) FK25230 and FK27899 installed. This amendment requires removal from service of these HP compressor rotor rear stage 5 and 6 discs and cone shafts, before reaching newly reduced life limits. This amendment is prompted by three reports of crack indications in the stage 5 and stage 6 blade loading slots, found during engine overhaul. We are issuing this AD to prevent stage 5 and 6 disc crack initiation and propagation leading to uncontained disc failure and damage to the airplane.