Summary
The FAA proposes to adopt a new airworthiness directive (AD) for all CFM International, S.A. (CFM) LEAP-1B21, LEAP-1B23, LEAP-1B25, LEAP-1B27, LEAP-1B28, LEAP-1B28B1, LEAP-1B28B2, LEAP-1B28B2C, LEAP- 1B28B3, LEAP-1B28BBJ1, and LEAP-1B28BBJ2 model turbofan engines. This proposed AD was prompted by the detection of melt-related freckles in the billet, which may reduce the life of certain compressor rotor stages 6-10 spools, high pressure turbine (HPT) rotor mid seals, HPT rotor stage 2 disks, low pressure turbine (LPT) stage 2 disks, and LPT stage 3 disks. This proposed AD would require revising the airworthiness limitations section (ALS) of the applicable CFM LEAP-1B Engine Shop Manual (ESM), and the operator's existing approved continuous airworthiness maintenance program (CAMP) to incorporate reduced life limits for these parts. The FAA is proposing this AD to address the unsafe condition on these products.