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

The FAA is adopting 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 intermediate pressure (IP) turbine discs, part numbers (P/Ns) FK21117 and FK33083 installed. This AD requires removal from service of these IP turbine discs based on newly established reduced turbine disc life limits. This AD is prompted by reports of two IP turbine blade release incidents as a result of dust caps separating from the blades and subsequent improved modeling analysis. We are issuing this AD to prevent uncontained IP turbine disc failure and damage to the airplane.