Federal investigators are probing the loss of a fan blade in a deadly Southwest engine failure.
One passenger was killed Tuesday on a Dallas-bound Southwest flight after an engine exploded, causing shrapnel to cut into the Boeing 737-700's fuselage, or the body of the plane. It blew out out a window and depressurized the cabin.
Passengers aboard Southwest Flight 1380 had rushed to pull the victim back into the plane after she was partially sucked out of a window, witnesses said. It was the first fatality on a U.S. airline since 2009.
The plane was climbing past 32,500 feet when indicators on the left engine started falling to zero and vibration significantly increased, said National Transportation Safety Board Chairman Robert Sumwalt. The cabin altitude warning started going off "shortly thereafter," which Sumwalt says usually occurs around 14,000 feet.
The plane made an unprompted roll on its left side at a 41 degree angle, he said, adding that rolls are rarely greater than 20 to 25 degrees. The plane made an emergency landing without using the usual amount of flaps, which help it slow down. It touched down at around 190 miles per hour, Sumwalt said, faster than the typical 155 miles per hour.
The entire event lasted twenty-two minutes, he said.
A missing fan blade appears to have cracked in two places, Sumwalt said. Investigators have evidence of an initial fatigue fracture on the inside of a blade near the hub that appears to have caused a second fracture about halfway down.