The exploded engine of the Southwest Airlines flight that left one passenger dead.

PARIS: US Federal Aviation Administration said on Wednesday that it would order the inspection of 220 jet engines after investigators said a broken fan blade was the cause of an engine explosion on a Southwest Airlines flight that shattered a window and killed a passenger.

The order, called an air-worthiness directive, would require an ultrasonic inspection within the next six months of the fan blades on all CFM56-7B engines that have accrued a certain number of takeoffs.

Global airlines, too, began inspecting some Boeing 737 engines on Wednesday.

Engine-maker CFM says there are more than 8,000 of its CFM56-7B engines in operation on Boeing 737 passenger jets.

Although no cause has been ruled out, the first fatal US airline accident since 2009 is expected to focus attention on metal fatigue in engine accidents, which are rare.

An early review of Tuesday's failed Southwest engine found preliminary evidence of metal fatigue where a fan blade had broken off, Mr Robert Sumwalt, chairman of the US National Transportation Safety Board, told reporters.

"We are very concerned," Mr Sumwalt said, referring to the overall challenge of detecting slow-developing metal fatigue.

Completing the latest investigation will take about 12 to 15 months, he said.

Korean Air, Japan Airlines, Ireland's Ryanair and Canada's WestJet all said they are carrying out checks. Not all airlines operating 737s are affected.</s>The FAA has ordered inspections on engine fan blades like the one that snapped off a Southwest Airlines plane, leading to the death of a woman who was partially blown out a window.

The Federal Aviation Administration's announcement late Wednesday comes nearly a year after the engine's manufacturer recommended the additional inspections, and a month after European regulators ordered their airlines to do the work.

Pressure for the FAA to act grew after an engine on a Southwest plane blew apart on Tuesday, showering the aircraft with debris and shattering a window.

A woman sitting next to the window was partially blown out and died of her injuries. The plane, which was headed from New York to Dallas, made an emergency landing in Philadelphia.

Investigators said a blade that broke off mid-flight and triggered the fatal accident was showing signs of metal fatigue - microscopic cracks that can splinter open under the kind of stress placed on jetliners and their engines.

The National Transportation Safety Board also blamed metal fatigue for an engine failure on a Southwest plane in Florida in 2016.

That led manufacturer CFM International, a joint venture of General Electric Co. and France's Safran SA, to recommend last June that airlines conduct the inspections of fan blades on many Boeing 737s.

The FAA proposed making the recommendation mandatory in August but never issued a final decision.

On Wednesday, the FAA said it would issue a directive in the next two weeks to require ultrasonic inspections of fan blades on some CFM56-7B engines after they reach a certain number of takeoffs and landings. Blades that fail inspection would need to be replaced.

It was not immediately clear how many planes would be affected. Last year, the FAA estimated that an order would cover 220 engines on U.S. airlines. That number could be higher now because more engines have hit the number of flights triggering an inspection.

Southwest announced its own program for similar inspections of its 700-plane fleet over the next month. United Airlines executives said Wednesday that they had begun inspecting some of their planes.

American Airlines has about 300 planes with that type of engine, and Delta Air Lines has about 185. It will not be clear until the FAA issues its rule how many will need inspections.

Tuesday's emergency broke a string of eight straight years without a fatal accident involving a U.S. airliner.

"Engine failures like this should not occur," Robert Sumwalt, chairman of the NTSB, said Wednesday.

Sumwalt expressed concern about such a destructive engine failure but said he would not yet draw broad conclusions about the safety of CFM56 engines or the entire fleet of Boeing 737s, the most popular airliner ever built.

Federal investigators were still trying to determine how a window came out of the plane. The woman sitting next to it, identified by family members as 43-year-old Jennifer Riordan, was wearing a seat belt. Philadelphia's medical examiner said the banking executive and mother of two from Albuquerque, New Mexico, died from blunt impact trauma to her head, neck and torso.

It is unknown whether the FAA's original directive would have forced Southwest to quickly inspect the engine that blew up. CEO Gary Kelly said it had logged only 10,000 cycles since being overhauled.

Before Wednesday's announcement, critics accused the FAA of inaction in the face of a threat to safety.

Robert Clifford, a lawyer who is suing American Airlines over another engine explosion that caused a fire that destroyed the plane, said the FAA should have required the inspections - even if it meant grounding Boeing 737s.

"There is something going on with these engines," he said, "and the statistical likelihood of additional failures exists."

William Waldock, a safety expert at Embry-Riddle Aeronautical University, predicted the FAA's decision. He said the scope of FAA action will depend on whether investigators find fatigue in other fan blades on the broken engine.

"The first thing they probably are going to do is pull every single one of those other blades off and X-ray them to see if they've got a similar type of failure waiting to happen," he said.

The Southwest CEO protested that it is too soon to say whether Tuesday's accident is related to any other engine failures.

Kelly said the plane was inspected on Sunday and nothing appeared out of order. A spokeswoman said it was a visual inspection and oil service of the engines. The NTSB's Sumwalt said, however, that the kind of wear seen where the missing fan blade broke off would not have been visible just by looking at the engine.</s>(Reuters) - The National Transportation Safety Board on Wednesday was inspecting the wrecked engine of a Southwest Airlines Co jet that blew up in mid air, killing a passenger in the first deadly U.S. commercial airline accident in nine years.

NTSB officials retrieved the flight data recorder from the Boeing 737-700, which will be sent to Washington for review, as airlines around the world stepped up inspection of engines on that model of aircraft.

Southwest Flight 1380, which took off from New York for Dallas, Texas, with 144 passengers and five crew members aboard, made an emergency landing in Philadelphia on Tuesday after an engine on the plane ripped apart, killing bank executive Jennifer Riordan, 43.

It was the second incident involving a failure of the same sort of engine, the CFM56, made by a partnership of France’s Safran and General Electric, on a Southwest jet in the past two years.

Passengers described scenes of panic as a piece of shrapnel from the engine shattered a window on the aircraft, almost sucking a female passenger out.

“All I could think of in that moment was, I need to communicate with my loved ones,” passenger Marty Martinez told ABC’s Good Morning America on Wednesday. During the incident, he logged on to the plane’s in-flight WiFi service to send messages to his family.

“I thought, these are my last few moments on Earth and I want people to know what happened,” Martinez said.

Southwest Airlines experienced an unrelated safety incident early on Wednesday when a Phoenix-bound flight was forced to land at Nashville airport shortly after takeoff because of bird strike.

The airline said it would inspect the fan blades of CFM56 engines on all of its 737 jets within 30 days. Minimal flight disruptions may result, it said.

NTSB Chairman Robert Sumwalt said on Tuesday at the Philadelphia airport that a preliminary investigation found an engine fan blade missing, having apparently broken off, and that there was metal fatigue at the point where it would normally be attached.

Sumwalt said the investigation could take 12 to 15 months to complete.

In August 2016, a Southwest flight made a safe emergency landing in Pensacola, Florida, after a fan blade separated from the same type of engine and debris ripped a hole above the left wing. That incident prompted the U.S. Federal Aviation Administration to propose last year that similar fan blades undergo ultrasonic inspections and be replaced if they failed.

Riordan’s death was the first in a U.S. commercial aviation accident since 2009, according to NTSB statistics.

Riordan was a Wells Fargo banking executive and well-known community volunteer from Albuquerque, New Mexico, according to a Wells Fargo official, who spoke on condition of anonymity.</s>NEW YORK: The US Federal Aviation Administration said it is set to issue new guidelines to inspect jet engines like the one that ruptured during a recent Southwest Airlines flight.

Within the next two weeks rules requiring "an ultrasonic inspection of fan blades" of certain jet engines "when they reach a certain number of takeoffs and landings" will be issued, the FAA said in a late Wednesday statement.

Blades that fail the inspection will have to be replaced, the FAA said.

The directive comes after the left engine of Southwest Airlines Flight 1380 suddenly blew apart during a Tuesday flight from New York to Dallas. The shrapnel shattered a window and depressurised the cabin, partially sucking a woman out of the plane.

Fellow passengers pulled the woman - identified as Jennifer Riordan, 43 - back in, but she later died of her injuries.

Robert Sumwalt, head of the National Transportation Safety Board (NTSB), said that a first inspection of the Boeing 737's damaged engine showed that an engine fan blade was missing, apparently broken due to metal fatigue.

The incident damaged the engine external covering, known as cowling, where several blade fragments were discovered once the plane landed, Sumwalt said on Wednesday.

"I'm very concerned about this particular event," Sumwalt said.

The CFM56-7B jet engine in question, made by CFM International - a joint venture of General Electric and France's Safran - is widely used around the world on Boeing 737s and has a solid record of safety.

"If we feel there is a deeper issue, we have the capability to issue urgent safety recommendations," Sumwalt added.

Southwest earlier announced extra inspections of the CFM-56 engines in their fleet, which should be completed within 30 days.

A similar accident on a Southwest Airlines flight in August 2016 forced the aircraft, also a 737 equipped with the CFM-56 engine, to make an emergency landing in Florida.

There were no casualties in that accident.

CFM International has called on airlines to carry out additional engine inspections, according to US media reports.

The captain of SW Flight 1380, Tammie Jo Shults - one of the first women fighter pilots in the US Navy - was widely praised as an American hero for calmly landing her stricken jet after the midair engine explosion.

Shults and her co-pilot, Darren Ellisor, said in a statement late Wednesday that they are focusing on work and not conducting media interviews.

"We all feel we were simply doing our jobs," they said, referring to the accident.

"On behalf of the entire crew, we appreciate the outpouring of support from the public and our coworkers as we all reflect on one family's profound loss."</s>A preliminary investigation into the exploded jet engine from this week's disastrous Southwest Airlines flight has revealed signs of "metal fatigue" that could have caused the incident.

The plane was flying from New York to Dallas when the engine explosion forced it into an emergency landing on Tuesday.

Shrapnel from the engine smashed a window and almost sucked out passenger Jennifer Riordan, who tragically died after the event.

Now, the US National Transport Safety Board has examined the blown engine of the Boeing 737.

According to chairman Robert Sumwalt, the engine's fan blades were separated and missing. The blade was separated at the point where it would come into the hub and there was evidence of "metal fatigue".

Metal fatigue occurs when prolonged stress is put on the material and can be exacerbated through structural damage caused by accumulated small cracks.

The examination of the engines will continue and officials believe the full investigation into what happened could take between 12 and 15 months.

The U.S. Federal Aviation Administration has said it will order inspection of about 220 aircraft engines as a result of the findings.

The regulator said late on Wednesday it plans to finalize the air-worthiness directive within the next two weeks. The order, which it initially proposed in August following an incident in 2016, will require ultrasonic inspection within the next six months of the fan blades on all CFM56-7B engines that have accrued a certain number of takeoffs.

Airlines said that because fan blades may have been repaired and moved to other engines, the order would affect far more than 220 of the CFM56-7Bs, which are made by a partnership of France's Safran and General Electric.

The CFM56 engine on Southwest flight 1380 blew apart over Pennsylvania on Tuesday, about 20 minutes after the Dallas-bound flight left New York's LaGuardia Airport with 149 passengers aboard.

Southwest has said it will inspect all similar engines in its fleet over the next 30 days.

Meanwhile, tributes continue to pour in for Jennifer Riordan, 43, who died following the event.

The mum-of-two's cause of death was confirmed as blunt impact trauma to her head, neck and torso.

Spokesman James Garrow of the Philadelphia Department of Public Health said Mrs Riordan's death was ruled accidental.

Seven additional passengers were treated for minor injuries.</s>PHILADELPHIA -- U.S. airline regulators have ordered inspections on engine fan blades like the one that snapped off a Southwest Airlines plane, leading to the death of a woman who was partially blown out a window.

The Federal Aviation Administration's announcement late Wednesday comes nearly a year after the engine's manufacturer recommended the additional inspections, and a month after European regulators ordered their airlines to do the work.

Pressure for the FAA to act grew after an engine on a Southwest plane blew apart on Tuesday, showering the aircraft with debris and shattering a window. A woman sitting next to the window was partially blown out and died of her injuries. The plane, which was headed from New York to Dallas, made an emergency landing in Philadelphia.

Investigators said a blade that broke off mid-flight and triggered the fatal accident was showing signs of metal fatigue -- microscopic cracks that can splinter open under the kind of stress placed on jetliners and their engines.

The National Transportation Safety Board also blamed metal fatigue for an engine failure on a Southwest plane in Florida in 2016.

That led manufacturer CFM International, a joint venture of General Electric Co. and France's Safran SA, to recommend last June that airlines conduct the inspections of fan blades on many Boeing 737s.

The FAA proposed making the recommendation mandatory in August but never issued a final decision.

On Wednesday, the FAA said it would issue a directive in the next two weeks to require ultrasonic inspections of fan blades on some CFM56-7B engines after they reach a certain number of takeoffs and landings. Blades that fail inspection would need to be replaced.

It was not immediately clear how many planes would be affected. Last year, the FAA estimated that an order would cover 220 engines on U.S. airlines. That number could be higher now because more engines have hit the number of flights triggering an inspection.

Southwest announced its own program for similar inspections of its 700-plane fleet over the next month. United Airlines executives said Wednesday that they had begun inspecting some of their planes.

American Airlines has about 300 planes with that type of engine, and Delta Air Lines has about 185. It will not be clear until the FAA issues its rule how many will need inspections.

Tuesday's emergency broke a string of eight straight years without a fatal accident involving a U.S. airliner.

"Engine failures like this should not occur," Robert Sumwalt, chairman of the NTSB, said Wednesday.

Sumwalt expressed concern about such a destructive engine failure but said he would not yet draw broad conclusions about the safety of CFM56 engines or the entire fleet of Boeing 737s, the most popular airliner ever built.

Federal investigators were still trying to determine how a window came out of the plane. The woman sitting next to it, identified by family members as 43-year-old Jennifer Riordan, was wearing a seat belt. Philadelphia's medical examiner said the banking executive and mother of two from Albuquerque, New Mexico, died from blunt impact trauma to her head, neck and torso.

It is unknown whether the FAA's original directive would have forced Southwest to quickly inspect the engine that blew up. CEO Gary Kelly said it had logged only 10,000 cycles since being overhauled.

Before Wednesday's announcement, critics accused the FAA of inaction in the face of a threat to safety.

Robert Clifford, a lawyer who is suing American Airlines over another engine explosion that caused a fire that destroyed the plane, said the FAA should have required the inspections -- even if it meant grounding Boeing 737s.

"There is something going on with these engines," he said, "and the statistical likelihood of additional failures exists."

William Waldock, a safety expert at Embry-Riddle Aeronautical University, predicted the FAA's decision. He said the scope of FAA action will depend on whether investigators find fatigue in other fan blades on the broken engine.

"The first thing they probably are going to do is pull every single one of those other blades off and X-ray them to see if they've got a similar type of failure waiting to happen," he said.

The Southwest CEO protested that it is too soon to say whether Tuesday's accident is related to any other engine failures.

Kelly said the plane was inspected on Sunday and nothing appeared out of order. A spokeswoman said it was a visual inspection and oil service of the engines. The NTSB's Sumwalt said, however, that the kind of wear seen where the missing fan blade broke off would not have been visible just by looking at the engine.</s>April 18 (UPI) -- The National Transportation Safety Board said the faulty engine on a Southwest Airlines plane that made an emergency landing in Philadelphia -- and killed a woman -- was missing a fan blade.

The Dallas-bound Boeing 737 from New York was forced to land in Philadelphia on Tuesday when an engine exploded with 143 passengers and five crew members aboard.

Jennifer Riordan was partly expelled from the fuselage through a broken window, due to the rapidly escaping air pressure. She died later at a Philadelphia hospital.

NTSB Chairman Robert Sumwalt said at a press conference Tuesday that a fan blade was missing from the engine assembly and there was evidence of "metal fatigue" where it separated.

"There's much more to be done on this," Sumwalt said.

Metal fatigue typically begins with a small surface fracture or hole and slowly grows in size.

Riordan's was the first death for Southwest Airlines.

"On behalf of the entire Southwest family, I'd like to extend my sincerest sympathies," Southwest CEO Gary Kelly said in a statement. "I am immensely grateful there are no other reports of injuries."

The 43-year-old mother of two served as the vice president of community relations at Wells Fargo Bank in Albuquerque, N.M. She'd managed the volunteer service of more than 1,000 employees since 2008.

Albuquerque Mayor Tim Keller said in a statement that Riordan was a "thoughtful leader" who had been "part of the fabric of our community."

One of her past employers, the University of New Mexico Health Sciences Center, described Riordan as an "amazing community leader, team member, wife and mother."

The pilot of the aircraft, Tammie Jo Shults, was praised for her actions during the crisis. At 32,000 feet, she kept the plane steady as she planned the emergency descent -- not long after the flight had departed LaGuardia International Airport.

Passenger Diana McBride Self wrote on Facebook, "Her grace and knowledge under pressure were remarkable. She came through the plane personally to check on us after she landed our crippled airplane. ... We were truly all in amazing hands."

Another passenger praised Shults for "nerves of steel."

Shults was among the first female U.S. military fighter pilots and the first woman to fly an F/A-18 Hornet for the U.S. Navy.</s>(Reuters) - The U.S. Federal Aviation Administration said it will order inspections of at least 220 aircraft engines as investigators are focusing on a broken fan blade in an engine that exploded Tuesday on a Southwest Aiirlines flight, killing a passenger.

The regulator said late on Wednesday it plans to finalize the air-worthiness directive within the next two weeks.

The order, which it initially proposed in August following an engine failure in 2016 on another Southwest Airlines Co flight, will require ultrasonic inspection within the next six months of fan blades on all CFM56-7B engines that have accrued a certain number of takeoffs, while others will need inspections within 18 months.

Airlines said that because fan blades may have been repaired and moved to other engines, the order would affect far more than 220 of the CFM56-7Bs, which are made by a partnership of France’s Safran and General Electric.

An FAA official acknowledged the total number covered may be higher. Some critics have questioned why the FAA did not move faster, when European regulators issued an April 2 directive ordering similar CFM56-7B inspections within nine months.

The CFM56 engine on Southwest flight 1380 blew apart over Pennsylvania on Tuesday, about 20 minutes after the Dallas-bound flight left New York’s LaGuardia Airport with 149 people on board. The explosion sent shrapnel ripping into the fuselage of the Boeing 737-700 plane and shattered a window.

Bank executive Jennifer Riordan, 43, was killed when she was partially pulled through the gaping hole as the cabin suffered rapid decompression. Fellow passengers were able to pull her back inside but she died of her injuries.

Videos posted on social media showed passengers grabbing for oxygen masks and screaming as the plane, piloted by Tammie Jo Shults, a former U.S. Navy fighter pilot, prepared for the descent into Philadelphia.

Shults and the first officer in a joint statement declined media interviews. “We all feel we were simply doing our jobs. Our hearts are heavy,” the pair said.

On Wednesday, National Transportation Safety Board (NTSB) Chairman Robert Sumwalt said the incident began when one of the engine’s 24 fan blades snapped off from its hub. Investigators found that the blade had suffered metal fatigue at the point of the break.

Sumwalt said he could not yet say if the incident, the first deadly passenger airline accident in the United States since 2009, pointed to a fleet-wide problem in the Boeing 737-700.

Southwest crews were inspecting similar engines the airline had in service, focusing on the 400 to 600 oldest of the CFM56 engines, according to a person with knowledge of the situation.

It was the second time this kind of engine had failed on a Southwest jet in the past two years, prompting airlines around the world to step up inspections.

A NTSB inspection crew was also combing over the Boeing 737-700 for signs of what caused the engine to explode.

Investigators expected to remain on the scene into the weekend but the NTSB did not plan any media update on Thursday. The NTSB investigation could take 12 to 15 months to complete, Sumwalt said.

Sumwalt said the fan blade, after suffering metal fatigue where it attached to the engine hub, has a second fracture about halfway along its length. Pieces of the plane were found in rural Pennsylvania by investigators who tracked them on radar. The metal fatigue would not have been observable by looking at the engine from the outside, Sumwalt said.

The GE-Safran partnership that built the engine said it was sending about 40 technicians to help with Southwest’s inspections. Southwest said it expected to wrap up its inspection of the engines it was targeting in 30 days.

In August 2016, a Southwest flight made a safe emergency landing in Pensacola, Florida, after a fan blade separated from the same type of engine and debris ripped a hole above the left wing. That incident prompted the FAA to propose last year that similar fan blades undergo ultrasonic inspections and be replaced if they failed.</s>PHILADELPHIA (AP) - A preliminary examination of the blown jet engine of the Southwest Airlines plane that set off a terrifying chain of events and left a businesswoman hanging half outside a shattered window showed evidence of "metal fatigue," according to the National Transportation Safety Board.

Passengers scrambled to save the woman from getting sucked out the window that had been smashed by debris. She later died, and seven others were injured.

The pilots of the twin-engine Boeing 737 bound from New York to Dallas with 149 people aboard took it into a rapid descent Tuesday and made an emergency landing in Philadelphia. Oxygen masks dropped from the ceiling and passengers said their prayers and braced for impact.

"I just remember holding my husband's hand, and we just prayed and prayed and prayed," said passenger Amanda Bourman, of New York.

The dead woman was identified as Jennifer Riordan, a Wells Fargo bank executive and mother of two from Albuquerque, New Mexico. The seven other victims suffered minor injuries.

The National Transportation Safety Board sent a team of investigators to Philadelphia.

In a late night news conference, NTSB chairman Robert Sumwalt said one of the engine's fan blades was separated and missing. The blade was separated at the point where it would come into the hub and there was evidence of metal fatigue, Sumwalt said.

The engine will be examined further to understand what caused the failure. The investigation is expected to take 12 to 15 months.

Photos of the plane on the tarmac showed a missing window and a chunk gone from the left engine, including part of its cover. A piece of the engine covering was later found in Bernville, Pennsylvania, about 70 miles (112 kilometers) west of Philadelphia, Sumwalt said.

As a precaution, Southwest said Tuesday night that it would inspect similar engines in its fleet over the next 30 days.

Passengers praised one of the pilots, Tammie Jo Shults, for her cool-headed handling of the emergency. The former Navy pilot was at the controls when the plane made the emergency landing. She walked through the aisle and talked with passengers to make sure they were OK after the aircraft touched down.

"She has nerves of steel. That lady, I applaud her," said Alfred Tumlinson, of Corpus Christi, Texas. "I'm going to send her a Christmas card, I'm going to tell you that, with a gift certificate for getting me on the ground. She was awesome."

In a recording of conversations between the cockpit and air traffic controllers, an unidentified crew member reported that there was a hole in the plane and "someone went out."

Tumlinson said a man in a cowboy hat rushed forward a few rows to grab the woman and pull her back in.

"She was out of the plane. He couldn't do it by himself, so another gentleman came over and helped to get her back in the plane, and they got her," he said.

Passengers struggled to somehow plug the hole while giving the badly injured woman CPR.

As the plane came in for a landing, everyone started yelling to brace for impact, then clapped after the aircraft touched down safely, Bourman said.

Southwest CEO Gary Kelly said there were no problems with the plane or its engine when it was inspected on Sunday.

The jet's CFM56-7B engines were made by CFM International, jointly owned by General Electric and Safran Aircraft Engines of France. CFM said in a statement that the CFM56-7B has had "an outstanding safety and reliability record" since its debut in 1997.

Last year, the engine maker and the Federal Aviation Administration instructed airlines to make ultrasonic inspections of the fan blades of engines like those on the Southwest jet. The FAA said the move was prompted by a report of a fan blade failing and hurling debris. A Southwest spokeswoman said the engine that failed Tuesday was not covered by that directive, but the airline announced it would speed up ultrasonic inspections of fan blades of its CFM56-series engines anyway.

"There's a ring around the engine that is meant to contain the engine pieces when this happens," said John Goglia, a former NTSB member. "In this case it didn't. That's going to be a big focal point for the NTSB - why didn't (the ring) do its job?"

In 2016, a Southwest Boeing 737-700 blew an engine as it flew from New Orleans to Orlando, Florida, and shrapnel tore a 5-by-16-inch hole just above the wing. The plane landed safely. The NTSB said a fan blade had broken off, apparently because of metal fatigue.

Koenig reported from Dallas. Associated Press writers Kristen de Groot and Claudia Lauer in Philadelphia; Susan Montoya in Albuquerque, New Mexico; and Matthew Barakat in Washington, contributed to this story, along with AP researchers Monika Mathur and Jennifer Farrar.</s>
• Southwest Airlines Flight 1380 suffered an uncontained failure of its left engine on Tuesday.
• In August 2016, Southwest Airlines Flight 3472 also suffered an uncontained failure of its left engine.
• Both engines are CFM56 turbofans and failed when one of its fan blades snapped off mid-flight.

A Southwest Airlines Boeing 737-700 suffered a catastrophic failure of its left engine on Tuesday and was forced to make an emergency landing in Philadelphia. Unfortunately, the incident resulted in the death of passenger Jennifer Riordan of Albuquerque, New Mexico.

According to the National Transportation Safety Board, investigators believe the left engine on Southwest Flight 1380 failed when one of its 24 titanium alloy fan blades snapped off mid-flight. The violent event caused the front cowling of the engine to disintegrate, firing shrapnel into the cabin of the aircraft.

The resulting loss of engine power and depressurization for the crew of Flight 1380 to make an emergency landing on the plane’s remain engine.

An initial examination of the engine found evidence of metal fatigue at the point where the blade failed.

For investigators, this is something they’ve seen before.

In August 2016, Southwest Airlines Flight 3472, another Boeing 737-700, also suffered an uncontained failure of its left engine that ripped off its front cowling. In this case, shrapnel also pierced the fuselage causing decompression forcing the flight to make an emergency landing Pensacola, Florida.

In both cases, the planes were powered by CFM International CFM56 turbofan engines. NTSB investigators believe that engine also failed when one of its fan blades snapped during flight. Again, metal fatigue is believed to have played a role in the 2016 incident.

Fortunately, the similarities end there. According to NTSB records, Flight 3472 resulted in no known injuries or fatalities among its 104 passengers and crew.

The CFM56 is one of the most popular commercial jet engines in the world and can be found on more than 6,700 aircraft. CFM International is a joint venture between GE Aviation and France’s Safran Aircraft Engines.

Read More about the Southwest Incident:
• Southwest passenger’s death was the first in a US passenger airline accident in more than 9 years
• Southwest pilot to air traffic control before emergency landing: ‘There’s a hole and someone went out’
• Southwest passenger says there was ‘blood everywhere’ after ‘terrifying’ emergency landing
• Southwest passenger who died after major engine failure has been identified as a Wells Fargo VP and mother of two
• Investigators found a major clue to what may have caused Southwest jet’s engine failure
• The type of engine that blew apart on Southwest plane was a growing concern for regulators
• The pilot who made the Southwest flight emergency landing is a former fighter pilot and one of the first women to fly an F-18
• Southwest passenger’s torso was sucked out of plane after engine explosion busted open aircraft window
The United States National Transportation Safety Board declares metal fatigue caused a fan blade failure that killed a passenger on April 16, the same issue behind a similar accident on another Southwest Airlines Boeing 737 in 2016. The Federal Aviation Administration announces mandatory ultrasonic inspections on fan blades fitted to CFM56-7B engines of which around 8,000 are flying worldwide.