Following Southwest accident, FAA orders inspections on certain CFM56-7B engines used in Boeing 737 aircraft within 20 days


The Federal Aviation Administration (FAA) issued an Emergency Airworthiness Directive (EAD) that requires operators to inspect fan blades on certain CFM56-7B engines within 20 days.

The directive is based on a CFM International Service Bulletin issued today and on information gathered from the investigation of Tuesday’s Southwest Airlines engine failure. The inspection requirement applies to CFM56-7B engines. Specifically, engines with more than 30,000 total cycles from new must complete inspections within 20 days.  The EAD becomes effective upon publication. The engine manufacturer estimates today’s corrective action affects 352 engines in the U.S. and 681 engines worldwide.


  1. The FAA’s AD contains a few odd points to me :
    Although CFMI Service Bulletin also recommends inspections by the end of August for fan blades with 20,000 cycles (on top of the same action as required by the AD), the FAA specifies :
    “CFM Service Bulletin CFM56-7B S/B 72-1033, dated April 20, 2018, provides actions for engines with fewer than 30,000 flight cycles, but this AD does not affect those engines.”

    Also, FAA specifies :
    “Although CFM Service Bulletin … specifies to report findings, this AD does not include that requirement.”

    Finally I found it a bit odd to read :
    “If any unserviceable indication …. is found during any inspection required by this AD, remove the affected fan blade from service before further flight.”
    Methinks that you won’t go far after having removed ONE fan blade ….

    The CFM56-7B is standard mount on all B737NGs.
    A320s are equipped with CFM56-5xx

    Note that another Southwest B737, N766SW, had also an uncontained engine failure in Aug 2016.
    The FAA can then be lauded for not having waited for the third incident before reacting ….



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