FAA Extends CFM56-7B Engine Inspections

The US FAA has published a new emergency airworthiness directive for the inspection of fan blades on CFM56-7B engines, bringing it into line with European safety regulators.

The new directive covers engines of the type involved in the fatal accident on a Southwest Airlines flight last month. One passenger died after the engine inlet cowl disintegrated causing debris to penetrate the fuselage with a resulting loss of cabin pressure and prompting an emergency landing.

The Federal Aviation Administration’s original directive, issued April 20, ordered inspections within 20 days of CFM56-7B fan blades with 30,000 or more total accumulated flight cycles since new. The directive affected 681 CFM engines worldwide, the FAA said at the time.

Since the that directive was issued, the FAA said it has been working closely with CFM “to develop an additional compliance plan to address the risk of fan blade failure for the entire CFM56-7B fleet.”

The new emergency directive requires initial and repetitive inspections of fan blades based on accumulated fan blade cycles. Operators will have to perform an initial inspection on each fan blade before it reaches 20,000 cycles since new, or within 113 days, whichever is later. The inspection will have to be repeated after no more than 3,000 cycles since the previous inspection.

The FAA estimates a total of 3,716 engines are affected in the United States by the new emergency directive. The cost of the inspections is estimated at USD$170 per engine, or $631,720 for the entire US fleet.