A new FAA Airworthiness Directive responding to the recent engine failure on a Southwest 737 will require initial and repetitive inspections of the fan blades in CFM56-7B engines, based on the accumulated fan-blade cycles, the FAA said on Tuesday. The AD (PDF), scheduled to be published on Wednesday, aims to “address the risk of fan-blade failure for the entire CFM56-7B fleet.” The FAA had issued an NPRM, prior to the recent failure, to address an unsafe condition based on a similar event that occurred in 2016. That proposal will be withdrawn, the FAA said, because the new action “represents a more comprehensive corrective action plan than previously proposed.”
The new AD requires operators to perform detailed inspections of each fan blade before the fan blade accumulates 20,000 cycles since new, or within 113 days from the effective date of the AD, whichever occurs later, then repeat the inspection after no more than 3,000 cycles. The required inspections will take about two hours, the FAA said, and if a fan blade needs to be replaced, it will cost about $8,500. The FAA estimates the AD will affect 3,716 engines installed on U.S.-registered airplanes. The AD is in addition to one that wasissued last month in response to the Southwest accident.
