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

The FAA is superseding Airworthiness Directive (AD) 2021-10-09 for certain CFM International, S.A. (CFM) CFM56-5B and CFM56-7B model turbofan engines with a certain high-pressure turbine (HPT) inner stationary seal installed. AD 2021-10-09 required removal, inspection, and replacement of the affected HPT inner stationary seal and, depending on the findings, replacement of the rotating air HPT front seal, HPT rotor blades, and No. 3 ball bearing. This AD was prompted by cracks found in the rotating air HPT front seal. After the FAA issued AD 2021-10-09, the manufacturer notified the FAA that the service information incorrectly lists the year of certain honeycomb repairs and that affected HPT inner stationary seals could potentially be installed on CFM CFM56-5C model turbofan engines. This AD requires removal, inspection, and replacement of the affected HPT inner stationary seal and, depending on the findings, replacement of the rotating air HPT front seal, HPT rotor blades, and No. 3 ball bearing. This AD also revises the applicability to add CFM CFM56-5C model turbofan engines. The FAA is issuing this AD to address the unsafe condition on these products.