Airworthiness Directives; CFM International, S.A. Engines
Key claim: The FAA proposes to supersede AD 2018-26-01 for CFM56-7B engines to require improved initial and repetitive ultrasonic or eddy current fan-blade crack inspections and replacement of affected parts based on updated CFM service material.
Abstract
(Proposed Rule · Transportation Department, Federal Aviation Administration) The FAA proposes to supersede Airworthiness Directive (AD) 2018-26-01, which applies to all CFM International, S.A. (CFM) Model CFM56-7B engines. AD 2018-26-01 requires initial and repetitive ultrasonic inspections or eddy current inspections of certain fan blades for crack indications and, depending on the results of the inspections, replacement with parts eligible for installation. Since the FAA issued AD 2018-26-01, CFM issued updated service material providing improvements to the ultrasonic inspection procedures and expanding the inspection area. This proposed AD would require initial and repetitive ultrasonic inspections or eddy current inspections of certain fan blades for crack indications and, depending on the results of the inspections, replacement with parts eligible for installation. The FAA is proposing this AD to address the unsafe condition on these products.
Why this matters
CFM56-7B engines power the global 737NG fleet, so tightening fan-blade crack inspections directly targets the failure mode implicated in prior uncontained fan-blade-out events. The supersedure shows FAA continuing to iterate on inspection technique and scope as fleet data accumulates, rather than treating the 2018 AD as a settled fix.