What We Already Know About the Southwest Airlines Engine That Failed

[thackney]

What We Already Know About the Southwest Airlines Engine That Failed
https://www.popularmechanics.com/flight/airlines/a19853760/southwest-airlines-flight-1380-engine-that-failed/
Apr 18, 2018

...NTSB Chair Robert Sumwalt said agency experts made a preliminary examination of the engine and found that “there’s evidence of metal fatigue where the blade separated from the hub." He added that a chunk of the engine cowling was discovered some 60 miles away from the airport....

...But while this type of incident is rare, the engine involved is one of the most widely used in commercial aviation—a fact that is causing concern in the industry as well as among the traveling public. The CFM56 engine, made by a joint venture of GE and France’s Safran SA, is used by 300 airlines on approximately 6,700 planes. A jet equipped with one of these engines takes off somewhere in the world about every two minutes.

Following two worrying incidents in 2016—one also involving a Southwest 737-700, the same model in this week’s accident—GE issued a service bulletin in June 2017 advising airlines to inspect the engines. At the time, Southwest said it would step up its schedule of planned maintenance checks on all CFM56 engines. The carrier operates more than 700 Boeing 737 jets of varying model types, 500 of which are the -700 series. United and Delta said today that they will be speeding up checks of similar engines in their fleets....

...However, he says, federal investigators will study at whether the schedule for mandatory inspections had slipped. There is precedent. Around ten years ago, the FAA launched a major audit of several airlines, including Southwest, for not performing required maintenance checks. The probe revealed a culture of coziness between government inspectors and the airlines they were monitoring.

Another factor to consider is the number of takeoff and landing cycles that a plane and its engines endure. More cycles means more wear and tear. Southwest is known for keeping its planes in the air more hours in the day than other major airlines, and it specializes in frequent service on its bread-and-butter short and medium-length routes....

[thackney]

The FAA will issue an Airworthiness Directive (AD) within the next two weeks that will require inspections of certain CFM56-7B engines. The directive will require an ultrasonic inspection of fan blades when they reach a certain number of takeoffs and landings. Any blades that fail the inspection will have to be replaced.

https://www.faa.gov/news/updates/?newsId=90105

[thackney]

Southwest Fatality Creates Rush For Ultrasound Inspections
https://aerospaceamerica.aiaa.org/southwest-fatality-creates-rush-for-ultrasound-inspections/

When the FAA sought public comment last year on a proposed rule requiring inspections of certain airliner engine fan blades, Southwest Airlines resisted, saying it would need 18 months to schedule and inspect the 732 affected engines in its fleet.

Southwest will now try to achieve that in one month, following Tuesday’s deadly accident in which a blade in the left engine of a Southwest Boeing 737-700 broke off, spraying debris and leading to the death of a passenger. The engine cowling was found in Bernville, Pennsylvania. Southwest Flight 1380 was flying from New York to Dallas when it had to make an emergency landing at Philadelphia International Airport.

CFM International, the joint venture of Safran Aircraft Engines and GE Aviation that makes the CFM56-7B engines, announced Wednesday that it will work with Southwest to complete “accelerated” ultrasonic inspections of the blades within 30 days. About 40 GE and Safran Aircraft Engines technicians will assist Southwest with the inspections.

The stakes are high for Southwest, because as CEO Gary Kelly noted in a Tuesday press conference, the airline’s entire fleet consists of 737-700s, each equipped with two CFM56-7B engines.

CFM has long been worried about the state of fan blades on these engines, some of which have many thousands of flight cycles, defined as the period from when the engine is started to when it is shut off. Last year, CFM recommended in a service bulletin that airlines remove certain fan blades and inspect them with ultrasonic devices “as soon as possible,” and no later than Sept. 24, 2017. The recommendation applied to engines with more than 15,000 flight cycles....

[thackney]

Click to enlarge

[WingNot]

This was from 2016 the planed landed in Pensacola.