Airworthiness Directive 2021-10-06
recurringAirworthiness Directives; CFM International, S.A. Turbofan Engines
What this AD requires
The FAA is adopting a new airworthiness directive (AD) for certain CFM International, S.A. (CFM) LEAP-1B model turbofan engines. This AD was prompted by multiple reports of pressure sub-system (PSS) unit faults due to pressure transducer corrosion following extended storage periods. For an engine in service, this AD requires checks for engine maintenance messages related to the pressure transducer and, depending on the results of the check, replacement of the PSS unit before further flight. The AD requires this repetitive check for faults prior to each flight until the PSS has accumulated at least 15 hours of electrical power. For an engine not in service, this AD requires applying electrical power to the PSS unit before further flight. The FAA is issuing this AD to address the unsafe condition on these products.
Which aircraft AD 2021-10-06 applies to
Applies only to engines with a pressure sub-system (PSS) unit installed having a serial number listed in CFM SB LEAP-1B-73-00-0038-01A-930A-D, Issue 002-00, dated April 25, 2021.
Whether AD 2021-10-06 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.