Airworthiness Directives; Rolls-Royce plc Turbofan Engines

We propose to adopt a new airworthiness directive (AD) for certain Rolls-Royce plc (RR) RB211-524B-02, RB211-524B2-19, RB211- 524B3-02, RB211-524B4-02, RB211-524B4-D-02, RB211-524C2-19, RB211- 524D4-19, RB211-524D4-39, and RB211-524D4X-19 turbofan engines. This proposed AD was prompted by several failures of affected high-pressure turbine (HPT) blades. This proposed AD would require removing affected HPT blades. We are proposing this AD to prevent failure of the HPT blade, which could lead to failure of one or more engines, loss of thrust control, and damage to the airplane.