Proposed rule · 2025-06382

Airworthiness Directives; CFM International, S.A. Engines

The FAA proposes to supersede Airworthiness Directive (AD) 2023-23-12, which applies to all CFM International, S.A. (CFM) Model LEAP-1B21, LEAP-1B23, LEAP-1B25, LEAP-1B27, LEAP-1B28, LEAP-1B28B1, LEAP-1B28B2, LEAP-1B28B2C, LEAP-1B28B3, LEAP-1B28BBJ1, and LEAP- 1B28BBJ2 (LEAP-1B) engines. AD 2023-23-12 requires replacing certain high-pressure turbine (HPT) rotor stage 1 disks and a certain compressor rotor stages 6-10 spool. Since the FAA issued AD 2023-23-12, the manufacturer has identified additional parts that were manufactured from material suspected to have reduced material properties due to iron inclusion, which prompted this proposed AD. This proposed AD would retain the requirements to replace certain HPT rotor stage 1 disks and a certain compressor rotor stages 6-10 spool. This proposed AD would also expand the applicability to include additional affected HPT rotor stage 1 disks that were manufactured from the same material suspected to have reduced material properties due to iron inclusion. The FAA is proposing this AD to address the unsafe condition on these products.