Three young Chinese citizens died and 182 people suffered injuries when Asiana Flight 214 from Seoul clipped a sea wall with its landing gear, then crashed and burst into flames, in the first commercial airliner disaster in the United States since 2009.
"In this investigation, we have learned that pilots must understand and command automation, and not become over-reliant on it," yesterday said acting chairman Christopher Hart of the National Transportation Safety Board (NTSB).
While the Boeing 777 was in the hands of "a seasoned flight crew with a good safety record, they misunderstood the automated systems at their command," Hart said.
The NTSB, which never explicitly assigns blame, refrained from explicitly accusing the Asiana crew of pilot error.
Also Read
Instead, it cited a long and varied list of contributing factors, from the Boeing 777's automated throttle system to pilot fatigue and jet lag after an otherwise routine 10-1/2 hour trans-Pacific hop.
Doing so put the auto-throttle on hold, meaning it would no longer automatically control airspeed, explained investigator-in-chief Bill English.
When the jet dipped below the correct glide path, Lee reacted by pulling the nose up -- but the auto-throttle, still on hold, failed to deliver an expected burst of engine power that would have enabled the airliner to make the runway.
"But the more complex automation becomes, the more challenging it is to ensure that pilots adequately understand it," he added.
English said Asiana, established in 1988 as a rival to Korean Air, emphasized "maximum use of automation" by its pilots, including the use of autopilots at as low as 330 meters from the ground.