BA Boeing Co

By Robert Wall and Doug Cameron 

The engine failure that killed a passenger aboard a Southwest Airlines Co. flight puts the spotlight on one of the industry's most commonly used engines.

CFM International -- a joint venture between General Electric Co. and France's Safran SA -- makes engines that have become a mainstay of commercial aviation. The engines power most of Boeing Co. and Airbus SE's single-aisle planes, the workhorses of the industry.

On Tuesday, one of two CFM56-7B engines ruptured on a Boeing 737-700 operated by Southwest. The engine broke apart while Southwest Flight 1380 was at cruising altitude, flying from New York's LaGuardia Airport to Dallas Love Field, with 149 passengers and crew aboard. Metal pieces struck the fuselage, though the details of what happened inside the cabin are still unclear.

Southwest two years ago suffered a similar failure on another CFM56 engine, forcing the plane to land but not resulting in injuries.

A probe of that incident showed evidence of fatigue cracks in some of the blades. In response, the Federal Aviation Administration last year proposed enhanced inspections of certain CFM engines. It hasn't yet made the safety fix mandatory. The National Transportation and Safety Board said it would examine whether there were any common factors connecting the two CFM56 incidents at Southwest.

The airline, meanwhile, said late Tuesday it was stepping up inspections of the CFM56s used in its fleet. CFM International said it was sending a team of experts to aid the NTSB probe.

The widespread use of the engine and its unusually dramatic failure are likely to spur more scrutiny across fleets around the globe. European air-safety regulators said Wednesday they were "assessing the situation" and working with U.S. counterparts.

On average, a CFM56-powered plane takes off somewhere in the world every two seconds. The CFM56-7B version involved in Tuesday's incident has been in service since 1997 and is used in more than 6,700 airliners.

Engine failures are rare but aren't unheard of. Robert Sumwalt, chairman of the NTSB, said investigators see about three to four incidents each year.

An Airbus A380 superjumbo operated by Air France in September suffered an engine failure on a flight from Paris to Los Angeles. The plane diverted to Goose Bay, Canada. The accident investigation hasn't been completed.

The engine of a Boeing 767 operated by American Airlines Group Inc. blew up in 2016 on takeoff from Chicago O'Hare International Airport because of unexpected component wear-and-tear. Passengers suffered injuries during the plane's evacuation.

Engines are the often-overlooked lifeblood of the aviation industry. Engine makers spend billions of dollars to eke out small-percentage improvements in fuel efficiency to woo airliner buyers.

Airlines and plane makers have endured a recent run of operational headaches because of problems with these mini power plants. British aircraft-engine maker Rolls-Royce Holdings PLC last week warned that some of its engines powering Boeing 787 Dreamliner long-haul planes would require more frequent inspections because components were wearing out faster than expected. U.S. regulators, as a precaution, have required airlines that use those engines to chart courses that bring planes closer to airfields to which they could divert.

Airlines that uses those engines have had to ground planes and cancel flights because of an earlier round of checks on them. Rolls-Royce, no longer affiliated with the luxury-car maker, has said it could take until at least 2021 to fix all the engines.

Pratt & Whitney, a unit of United Technologies Corp., has struggled with the development and production of its new geared turbofan engine. The engine maker has halted shipments to Airbus as it works to fix the design of components, which have been wearing out too soon. Airlines have had to idle planes in response to actions taken by European air-safety regulators. Pratt has said it is working to fix the problem.

CFM also is struggling with its newest engine, the Leap used on Boeing's new 737 Max narrow-body and some Airbus A320 models. GE Aviation President David Joyce last month said the company was about six weeks late on engine deliveries to Boeing and Airbus.

Write to Robert Wall at robert.wall@wsj.com and Doug Cameron at doug.cameron@wsj.com

(END) Dow Jones Newswires

April 18, 2018 08:28 ET (12:28 GMT)

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