Following the fatal engine failure that led to the mid-air accident of Southwest Flight 1380 earlier this week, the Federal Aviation Administration (FAA) has demanded a massive engine inspection, CNBC reports.
The FAA has issued an Emergency Airworthiness Directive (EAD) on Friday, April 20, regarding CFM56-7B engines — the same engine type on the Boeing 737 airplane involved in the Southwest accident on Tuesday, April 17.
According to the directive, airline operators are required to perform an inspection of the CFM56-7B engine fan blades, which in the case of Flight 1380, exploded at 32,000 feet, killing one passenger and forcing the Southwest Airlines airplane to make an emergency landing in Philadelphia.
“We are issuing this [airworthiness directive] because we evaluated all the relevant information and determined the unsafe condition described previously is likely to exist or develop in other products of the same type design,” notified the FAA.
The EAD applies to certain CFM56-7B engines, specifically those that have been used for more than 30,000 total cycles. A cycle is a unit measure for airplane use and runs from take-off to shut down after landing, CNBC notes.
Furthermore, the directive states that operators must complete this verification within 20 days.
The FAA will issue an airworthiness directive (AD) in the next two weeks requiring an ultrasonic inspection of fan blades of certain CFM56-7B turbofan engines https://t.co/5jINaM0oXv https://t.co/aM9NyZy5gH
— NelsonGarcíaPolanco (@NelsonGarciaPol) April 20, 2018
The EAD comes after the CFM56-7B engine manufacturer, CFM International, released a service bulletin calling for more rigid testing of this type of engine, the FAA explained.
The airline regulator also mentioned that data from the investigation on Boeing 737 engine failure factored into Friday’s emergency directive.
The CFM bulletin, also issued on Friday, recommends that the CFM56-7B fan blades be examined with an ultrasonic probe — a procedure that lasts for four hours per each of the airplanes’ engines and which can be performed without removing the engines from the aircrafts’ wings.
The reason why CFM is suggesting that operators conduct the CFM56-7B engine verifications via ultrasonic probe is that the fan blades might hide tiny cracks, which would not be detected with the naked eye.
According to CFM estimates, the inspection order will affect some 352 engines in the U.S. and 681 worldwide, specified the FAA.
— jason milligan (@jasonmi02398705) April 19, 2018
In addition, the engine manufacturer also recommends that operators verify the CFM56-7B engines with about 20,000 cycles as well. This will be applicable to an estimated 2,500 engines, states CFM.
The CFM56-7B engine is one of the most widely used airplane engines worldwide. Tuesday’s tragic failure of the popular engine model resulted in the first passenger fatality on a U.S. airline in the last nine years and the first accident-related passenger death ever recorded in the history of Southwest Airlines.