Asiana Airlines Flight 214 crashed July 6, 2103, at San Francisco International Airport. The National Transportation Safety Board will release its report into what caused the crash Tuesday, with recommendations to avoid another. / Marcio Jose Sanchez, AP
WASHINGTON - Nearly a year after the fatal crash of Asiana Airlines Flight 214 in San Francisco, federal investigators will determine Tuesday what caused the accident and make recommendations to avoid another.
The National Transportation Safety Board will release its report on the results of its investigation into the July 6, 2013, crash that killed three people and injured more than 200.
Investigators have already said the Boeing 777-200ER was flying lower and slower than intended when it slammed into the seawall at the end of the runway, spun around and burst into flames.
The board will vote on probable causes of the crash and then make non-binding recommendations, which are keenly awaited in the industry because of the expertise of the board and its staffers.
"We really look forward to seeing that report. We work not in the 'what happened,' but 'why it happened,'" said Michael Barr, who teaches aviation safety at the University of Southern California and has a commercial pilot's certificate. "The why is what's going to prevent the next accident."
The Asiana flight from Seoul was traveling about 119 mph, despite a goal of 158 mph, when it hit the seawall on a sunny morning. The airline acknowledged in documents filed in March that a "probable cause" of the accident was the pilots flying too slow.
But the pilots also said "inconsistencies" with the autothrottle contributed to the crash, which manufacturer Boeing dismissed in its filings. The problem was that after a change in an autopilot setting about 1,600 feet off the ground, the autothrottle went into "hold" mode that kept the engines idling, rather than maintaining speed, which the pilots didn't realize.
Asiana said in its filing the navigation equipment "led the crew to believe that the autothrottle was maintaining the airspeed set by the crew" and instead the equipment "disabled the aircraft's minimum airspeed protection" without an audible warning. The airline also said test pilots had trouble landing under the same conditions in simulators.
But Boeing said in its submission that the plane and all its systems were functioning as expected before the crash and "did not contribute to the accident." Boeing said Asiana pilots should have aborted their landing 500 feet off the ground - as stated by the airline's own policy - because of numerous cues that the plane's speed was lowering, the thrust setting was incorrect and the plane was flying too low.
Asiana said the pilots had plenty of experience, but the crash raised questions about whether pilots need more training to monitor sophisticated technology aboard planes.
At a December NTSB hearing, investigators said the flying pilot, Lee Kang Kuk, was landing for the first time at San Francisco and he had spent just 43 hours flying the 777, although he had clocked 9,684 hours on a variety of other jets. Another pilot serving as an instructor on the flight, Lee Jung Min, had spent 3,208 hours flying 777s out of 12,307 total flying hours.
Barr said the NTSB's conclusions are respected because they serve as a moderator in determining what went wrong, while an airline and manufacturer strongly assert their own positions.
"The NTSB has no dog in that fight," Barr said. "They will come down as close as they can to what can be proven."
Other key elements include survivability of the crash. Testimony at an NTSB hearing in December said the plane largely held together, despite coming down harder than certified to land, and seats remained intact until fire swept through the cabin.
But two of the evacuation slides made by Air Cruiser opened inside the cabin, pinning a flight attendant temporarily. The company was going to further test the equipment.
A firetruck ran over one of the three people who died as a result of the crash, 16-year-old Ye Meng Yuan, when she was covered in firefighting foam on the ground. Fire officials said the priority was to save hundreds of people inside the plane.
Barr, who called himself a big fan of rescue personnel, said crash investigations show what happens in practice rather than just in planning and engineering.
"There are things you can learn and take corrective action from that," Barr said of crash reports. "Nothing is wasted."
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