Pilots twice called to abort the landing of Asiana Flight 214 in the last few seconds before it crashed at the San Francisco airport last weekend, federal investigators said Thursday.
It was previously reported that a crew member called to abort the landing about 1.5 seconds before the crash Saturday at San Francisco International Airport. But Deborah Hersman, chairman of the National Transportation Safety Board, revealed in a briefing for reporters Thursday that there was also a previous call for a "go-around" — abandoning the landing attempt — about 3 seconds before impact.
Why the plane clipped a seawall at the airport remains a mystery. Hersman said reviews of the automated pilot system, the automated throttles and the flight director systems all showed "no anomalous behavior." And yet, two of the pilots were seeking in the final seconds to abort the landing.
Two Chinese teenagers were killed and about 180 other passengers were injured when the Boeing 777 crashed. Seventeen people remained in area hospitals Thursday, three of them — two adults and a child — in critical condition.
Most of the damage was toward the rear of the plane, whose tail was ripped off. That's where the two passengers who were killed were seated.
There was so little damage at the front of the plane that a firefighter told investigators that "if you just fluffed the pillows, you could turn the airplane around and it could go out on its next flight."
"As he walked back through the aircraft, it became more and more damaged as he moved aft," Hersman said.
The NTSB is trying to answer several questions. Hersman cleared up one of those earlier Thursday — telling NBC Bay Area that a flash of light the pilot reported having seen about 34 seconds before the crash wasn't a laser, which the Federal Aviation Administration says "can completely incapacitate pilots." Pointing one at an aircraft is a federal crime.
Hersman said later at the briefing that the light, which could have been a reflection of the sun, didn't affect the pilot's vision.
Another mystery is why the plane wasn't immediately evacuated. Hersman said Wednesday that the doors weren't opened until about 90 seconds after the plane had come to a full stop. The standard is to have the plane fully evacuated within 90 seconds.
It also remains unclear why the plane's evacuation chutes prematurely opened inside the cabin on the plane's second impact — they're supposed to open outward.
And investigators also want to know why flight data indicated that the plane's automated systems recorded multiple "autopilot and autothrottle modes" as it approached San Francisco.
"There is automation there to support the pilots, but pilots also have to fly the airplane," Hersman told NBC News on Wednesday. "They have to monitor, and they have to fly."
Hersman dismissed speculation that the use of cellphones or other electronic devices by passengers — which are supposed to be turned off once a plane descends below 10,000 feet — might have played a role.
"There is no indication at this point in time that any personal electronics interfered with the performance of the aircraft," Hersman said Thursday.
The Federal Aviation Administration told NBC News last month that it will likely relax that ban.
Runway could reopen
Officials said debris from the airliner has been cleared from the runway, which could reopen as soon as Sunday.
Hersman said the NTSB has returned the runway to the jurisdiction of officials at San Francisco International Airport, but she said a grassy area where the plane's fuselage rests remained under NTSB control.
Doug Yakel, a spokesman for the airport, told NBC News it would probably take a few days before Runway 28 Left was operational again, which could be late Sunday or early Monday.
Separately, emergency agencies are defending their response to the crash after recordings of passengers' and witnesses' calls to 911 reflected frantic concern that there weren't enough emergency crews on the scene.
Fire officials told NBC's TODAY that ambulances responded within 13 minutes and that private ambulances were already on the scene. The incident commander initially told them to keep away from the plane because of fears it could explode, they said.
A spokesman for American Medical Response, which provides ambulance services in 42 states, said ambulances had gone to a staging area before continuing to the wreckage in groups of five in accordance with a crash response plan.
Tom Costello and Ami Schmitz of NBC News contributed to this report.