Airworthiness Directives; Rolls-Royce plc Turbofan Engines

We propose to adopt a new airworthiness directive (AD) for certain Rolls-Royce plc (RR) RB211-22B and RB211-524 turbofan engines with low-pressure turbine (LPT) support roller bearing, part number (P/ N) LK30313 or P/N UL29651, installed. This proposed AD was prompted by a report of a breach of the turbine casing and release of engine debris. This proposed AD would require removal of certain LPT support roller bearings installed in RR RB211-22B and RB211-524 engines. We are proposing this AD to prevent failure of the LPT support roller bearing, loss of radial position following LPT blade failure, uncontained part release, damage to the engine, and damage to the airplane.