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FAA issues new airworthiness directive for all CFM56-7B engines in wake of Southwest 1380 accident
3 May 2018

The U.S. FAA issued a new airworthiness directive (AD) for all CFM International S.A. (CFM) Model CFM56-7B engines in the wake of the April 17 uncontained engine failure accident involving a Southwest Airlines Boeing 737-700.

The AD 2018-09-10 requires initial and repetitive inspections of the concave and convex sides of the fan blade dovetail to detect cracking and replacement of any blades found cracked.

The AD is effective May 14, 2018.

In response to the Southwest Airlines accident, the FAA issued Emergency AD 2018-09-51, to address certain high-time CFM56-7B engines, specifically including those with 30,000 or more total accumulated flight cycles since new. AD 2018-09-51 requires a one-time ultrasonic inspection (USI) of the concave and convex sides of the fan blade dovetail.
Since the issuance of that AD, the FAA states it has been working with CFM to develop an additional compliance plan to address the risk of fan blade failure for the entire CFM56-7B fleet. This AD addresses the unsafe condition affecting CFM56-7B engines by requiring initial and repetitive inspections of fan blades based on accumulated fan blade cycles.