Airworthiness Directive 2021-10-09
one-timeAirworthiness Directives; CFM International, S.A. Turbofan Engines
What this AD requires
The FAA is adopting a new airworthiness directive (AD) for all CFM International, S.A. (CFM) CFM56-5B and CFM56-7B model turbofan engines with a certain high-pressure turbine (HPT) inner stationary seal installed. This AD was prompted by cracks found in the rotating air HPT front seal. 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. The FAA is issuing this AD to address the unsafe condition on these products.
Which aircraft AD 2021-10-09 applies to
Applies only to engines with a high-pressure turbine (HPT) inner stationary seal, P/N 1808M56G01, installed with a serial number listed in CFM SB CFM56-5B S/B 72-0952, Revision 01 (dated January 15, 2020), or CFM SB CFM56-7B S/B 72-1054, Revision 01 (dated January 15, 2020); does not apply if that seal was later repaired per CFM56-5B ESM 72-41-03 REPAIR 003 or CFM56-7B ESM 72-41-03 REPAIR 003 after the year listed in the applicable SB table.
Whether AD 2021-10-09 actually applies to your aircraft (by serial and installed parts) and whether it’s already complied with comes from that aircraft’s records.
How AD compliance is recorded
A valid compliance record (14 CFR 43.9) states:
Tailplate reads a tail number’s logbooks and matches every applicable AD — including this one — to its compliance evidence, with recurring next-due dates computed.
Look up a tail number →Read the full directive (Federal Register)Applicability is derived from the FAA directive corpus and is advisory, not a legal airworthiness determination. Compliance is established only from an aircraft’s actual records.