This week, Southwest flight 1380 lost an engine in midair when one of
its fan-blades cracked; it was the second time in recent years that this
happened to one of Southwest’s Boeing 737s.
In September 2016, Southwest 3472 was forced to make an emergency
landing due to an engine failure when one of its fan-blades cracked. The
manufacturer, CFM, subsequently announced that its fan-blades could
develop dangerous internal cracks and asked the National Transportation
Safety Board to enact a rule requiring frequent ultrasonic checks of the
blades to detect cracks before they could cause engine failures.
Southwest filed comments with the NTSB objecting to the proposal, saying
that they have so many Boeing 737s that are prone to the fault and that
this would present a hardship. They insisted that their own inspection
regime was sufficient to detect cracks before they became serious.
