Airline regulators have ordered inspections on engine fan blades like the one that snapped off a Southwest Airlines plane and led to the death of a woman who was partially sucked out of a window on a New York City-to-Dallas flight earlier this week. That incident prompted the FAA to propose previous year that similar fan blades undergo ultrasonic inspections and be replaced if they failed.
"Engine failures like this should not occur", Robert Sumwalt, chairman of the NTSB, said Wednesday.
The National Transport and Safety Board (NTSB) said it would launch a full investigation into the incident on Tuesday morning.
An NTSB inspection crew pored over the Boeing (BA.N) 737-700 and its CFM56 engine, made by a partnership of France's Safran (SAF.PA) and General Electric (GE.N).
They were developed by French-US joint venture CFM International, which says it is the "world's leading supplier of jet engines for single-aisle aircraft".
Manufacturers regularly inspect engines for hidden cracks using X-ray machines or ultrasound devices - the same kind of technology doctors use to check the health of expectant mothers.
Investigators also said the plane landed at unusually high speed because the pilots feared losing control if they flew slower.
Southwest flight 1380 was traveling from NY to Dallas with 144 passengers and five crew members on Tuesday when it was forced to land in Philadelphia after one of the Boeing 737's engines exploded, blowing out a window. The woman who was almost sucked out of the plane's broken window Tuesday was wearing a seatbelt. "I feel for her two kids, her husband, the community that they lived in", an emotional Needum told reporters.More news: Ariana Grande's Cryptic Tweet Has Got Everyone Confused
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Videos posed on social media showed passengers grabbing for oxygen masks and screaming as the plane, piloted by 56-year-old Tammie Jo Shults, a former fighter pilot for the U.S. Navy, prepared for its descent into Philadelphia.
"Nobody got injured, but it was hauntingly parallel to what happened yesterday", CNN aviation analyst Miles O'Brien said. "There was a lot of blood because she was hit by some of the shrapnel coming off the engine after it exploded".
Cockpit recordings show how calmly Ms Shults dealt with the situation as the aircraft plunged towards the ground. "The cause that we're listing and have written on the death certificate sounds consistent with what has been reported", he said, but he could not say whether the injuries were caused by "the fuselage or the air or the window or debris".
Passengers praised Shults for her professionalism during the emergency.
"This is a sad day and our hearts go out to the family and the loved ones of the deceased customer", he said.
"I've always said, you give me a good person, I can make a good firefighter out of him". Twenty-two minutes later, Shults managed to land the Boeing 737 safely.
A second bang followed, said Marty Martinez, a 29-year-old digital marketing specialist heading home to Dallas. "Southwest 1380 it doesn't matter we will work it out there".
"We have part of the aircraft missing so we're going to need to slow down a bit", she said, adding that some passengers had been hurt.