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

The FAA is superseding an existing airworthiness directive (AD) for Rolls-Royce plc 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. That AD currently 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 AD requires removing these parts at new reduced cycle limits. This AD results from Rolls-Royce plc reducing the lives of these parts and changing the life calculating method to use "Standard Duty Cycles" with "Multiple Flight Profile Monitoring" and "Flight Cycles" with "Heavy Flight Profile Monitoring". We are issuing this AD to prevent stage 5 and 6 disc crack initiation and propagation that might lead to uncontained disc failure and damage to the airplane.