Summary
The FAA proposes to adopt a new airworthiness directive (AD) for certain Rolls-Royce plc (RR) RB211-524 and -535 series turbofan engines. This proposed AD would require initial and repetitive fluorescent penetrant inspections (FPI) and borescope inspections of the high pressure (HP) compressor stage 1 and 2 rotor discs for cracks. This proposed AD results from reports of low-cycle-fatigue cracks found at overhaul in the interface weld between the HP compressor stage 1 and 2 rotor disc. We are proposing this AD to prevent uncontained engine failure and damage to the airplane.