Updated: Wed, 10 Jul 2013 20:31:42 GMT | By M. Alex Johnson, Staff Writer

Investigators want to know whether pilots of crashed Asiana flight were fatigued

Investigators are looking closely at whether the pilots may have been fatigued when their Asiana Airlines flight crashed on landing last weekend in San Francisco, killing two passengers and injuring scores more.

Both of the main pilots told investigators that they had had plenty of rest, including eight hours of sleep, before the flight took off from Seoul, South Korea, Deborah Hersman, chairman of the National Transportation Safety Board, said at a news conference. 

They had an additional five-hour break during the flight, resuming control from a relief crew about 90 minutes before the Boeing 777 clipped the seawall at San Francisco International Airport on Saturday, shearing off the plane's tail. 

"We do, in our investigations, look at pilots' 72-hour history — their work and rest history —  to try to understand if they were fatigued [and] what conditions they were working under," she said.

Hersman said flight data also indicated that the pilots entered numerous commands into the plane's automated systems as it approached San Francisco. It wasn't immediately clear why, she said, saying investigators wanted to determine whether they understood the data they were getting.

Twenty people remained in San Francisco-area hospitals, four of them in critical condition, and some could face many months of recovery.

One of those critically injured is a child who is being treated at San Francisco General Hospital, the hospital said.

Questions so far have centered on the jet's air speed and alignment as it approached the runway. At least one of the pilots has told investigators that the crew was struggling to line the jet up properly and hadn't noticed that their air speed had fallen.

The pilot, Lee Kang Guk — a veteran behind the stick of other jetliners — was only halfway through the certification training process for the 777. He was being trained by another veteran pilot — was making his first trip as an instructor, the NTSB said.

The two passengers who were killed were both 16-year old Chinese girls who were on their way to summer camp in the U.S. China's consul general in San Francisco has set up a liaison office in the hotel where most of the Chinese survivors of the crash are staying, the Foreign Ministry said.

During opening remarks of talks between U.S. and Chinese leaders in Washington, Vice President Joe Biden expressed his condolences and offered sympathies to the victims' families Wednesday. 

"I want to start by expressing my sadness [and] the sadness of, quite frankly, the American people in the loss of two beautiful young lives, young Chinese students, in the Asiana plane crash on Saturday," Biden said. "Loss of those two young lives is, for families, the most devastating thing that happens in their lives."

For some of those remaining under treatment, the road to recovery could be a long one, doctors said.

Three patients in intensive care at San Francisco General could be there "for months," Margaret Knudson, the hospital's chief of surgery, told Business Week in a telephone interview Wednesday.

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Some of the patients have fractured spines, stretched ligaments and head injuries, painting a picture of people who were badly bounced around as the plane hit short of the runway and tumbled, Geoff Manley, vice chairman of neurological surgery at the University of California-San Francisco, told NBC News.

As the plane hit the ground, passengers would have been thrust forward, backward, up and down. 

"This is whiplash to the nth degree," Manley said. "People were being flipped forward and back as the plane crashed. When you bend forward or backward like that, you can literally crush" the vertebrae.

Ami Schmitz of NBC News contributed to this report.


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