Airworthiness Directives; CFM International, S.A. Turbofan Engines

The FAA is adopting a new airworthiness directive (AD) for certain CFM International, S.A. (CFM) LEAP-1A model turbofan engines. This 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 AD requires initial and repetitive borescope inspections (BSIs) of the HPT rotor stage 1 blades. Depending on the results of the BSIs, this AD requires either additional BSIs at reduced intervals or replacement of the HPT rotor stage 1 blades. This AD also requires sending the inspection results to CFM if any unserviceable finding is found. The FAA is issuing this AD to address the unsafe condition on these products.