Summary
The FAA proposes to adopt a new airworthiness directive (AD) for certain CFM International, S.A. (CFM) LEAP-1A model turbofan engines. This proposed AD was prompted by reports of two in-flight shutdowns (IFSDs) and subsequent investigation by the manufacturer that revealed cracks in the high-pressure turbine (HPT) rotor stage 1 blades. This proposed AD would require initial and repetitive borescope inspections (BSIs) of the HPT rotor stage 1 blades and HPT stator stage 1 nozzle set. Depending on the results of the BSIs, this proposed AD would require either additional BSIs at reduced intervals or replacement of the HPT rotor stage 1 blades or HPT stator stage 1 nozzle set. This proposed AD would also require sending the inspection results to CFM if any unserviceable finding is found. The FAA is proposing this AD to address the unsafe condition on these products.