A burned Boeing Co. 777, operated by Asiana Airlines Inc., sits on the runway after it crashed landed at San Francisco International Airport (SFO) in San Francisco, California, U.S., on Saturday, July 6, 2013. The plane, on a flight from Seoul, South Korea, crashed while making a routine landing at San Francisco International Airport, killing two and burning as passengers escaped down emergency slides. Photographer: David Paul Morris/Bloomberg via Getty Images
(USA Today) -- Federal crash investigators revealed Wednesday that the pilot flying Asiana Airlines flight 214 told them that he was temporarily blinded by a bright light when 500 feet above the ground.
Deborah Hersman, chairwoman of the National Transportation Safety Board, said it wasn't clear what could have caused the problem. Asked specifically whether it could have been a laser pointed from the ground, Hersman said she couldn't say what caused it.
"We need to understand exactly what that is," Hersman said. "It was a temporary issue."
RAW VIDEO: Man records plane crash in real time
Her comments came during a daily press briefing on the Saturday crash of Asiana Flight 214 that left two dead and another 168 injured.
Federal crash Investigators previously said that pilots recognized they were too low and not lined up precisely with the runway while still 500 feet from the ground. At 500 feet, pilots recognized that they were low as the Boeing 777 was going 134 knots and was 34 seconds from impact. They continued to make adjustments until hitting the seawall at the end of the runway at San Francisco International Airport.
Slideshow: Boeing 777 crashes while landing in San Francisco
Evacuation of the plane didn't begin immediately. Airlines must certify that they can evacuate fully loaded planes within 90 seconds. But in this case, a pilot told flight attendants not to begin the evacuation immediately when the plane came to rest.
But after about 90 seconds, a flight attendant near the second door reported seeing fire outside a window in the middle of the plane. He relayed that information to the cockpit and then the evacuation began.
Hersman said evacuations don't always begin immediately. But she said once the crew was aware of the fire, evacuations began.
"We need to understand what they were thinking," Hersman said.
Rescue trucks arrived within two minutes and began fighting the fire outside the plane within three minutes. Investigators found the right engine leaked oil where part of the fire was located.
Two flight attendants were pinned by evacuation slides that inflated inside the cabin, at the first and second doors from the front on the right side of the plane, Hersman said. One broke her lower leg, Hersman said.
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"Those flight attendants needed assistance to get out from underneath those slides," Hersman said. "They couldn't do it alone."
A total of three flight attendants were ejected from the plane after the tail was torn off, Hersman said. She had said Tuesday that at least two flight attendants were ejected. All three remain hospitalized and haven't been interviewed by investigators.
The flight also marked the first time that Lee Gang Guk had flown with Lee Jeong-Min, a trainer making his first trip as an instructor pilot.
"The question is why did it land short," said Kees Rietsema, a dean at Embry-Riddle Aeronautical University. "Obviously the captain is responsible, and in this case it's the instructor in the right seat who is responsible."
Investigators are now examining the working relationship of the two, and whether junior officers were comfortable challenging their managers, and whether senior pilots will welcome that feedback, Hersman said.
"That's what the airline needs to do, be responsible so that in the cockpit you're matching the best people, especially when you're introducing someone to a new aircraft," NTSB Chairman James Hall said.
Contributing: The Associated Press