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

FAA / Federal Register · 2022-00509

The FAA proposes to adopt a new airworthiness directive (AD) for all CFM International, S.A. (CFM) LEAP-1A23, LEAP-1A24, LEAP- 1A24E1, LEAP-1A26, LEAP-1A26CJ, LEAP-1A26E1, LEAP-1A29, LEAP-1A29CJ, LEAP-1A30, LEAP-1A32, LEAP-1A33, LEAP-1A33B2, and LEAP-1A35A 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 interstage seals, HPT rotor stage 2 disks, low pressure turbine (LPT) stage 1 disks, LPT stage 2 disks, LPT stage 3 disks, and LPT stage 4 disks. This proposed AD would require revising the airworthiness limitations section (ALS) of the applicable CFM LEAP-1A Engine Shop Manual (ESM) and the operator's existing approved continuous airworthiness maintenance program (CAMP) to incorporate reduced life limits for these parts. This proposed AD would also require the removal of certain LPT stage 4 disks identified by serial number (S/N) prior to their new life limits. The FAA is proposing this AD to address the unsafe condition on these products.