In the spring of 2013, an Asiana captain with nearly 10,000 flying hours, converting to the Boeing 777, watched a demonstration in the simulator. The autopilot and autothrottle were switched off, the thrust levers pulled back to idle, and the jet was left to slow toward a stall. Nobody touched anything. Then the autothrottle woke up by itself, added power and brought the speed back.
He later told investigators he was “astonished.”
The demonstration came from Boeing’s 777 training manual. It left something out. In some modes the wake-up does not happen. Those exceptions were listed in a different Boeing manual, not the training one, and Asiana’s course slide said simply that “autothrottles engage automatically (if armed).” The National Transportation Safety Board would later conclude that the demonstration likely gave him false confidence that the autothrottle would protect his speed at all times.
On July 6, 2013, he sat in the left seat of Asiana Flight 214 from Seoul, bringing 291 passengers into San Francisco late on a morning of good visibility. He was halfway through his supervised line training on the 777 and had 33 hours on the type. In the right seat, in command, sat his instructor, on his first flight as an instructor. A relief first officer watched from the jumpseat. The electronic glideslope for runway 28L was out of service for construction, so the descent was flown by eye. The trainee later said he was “stressed” about that. The cockpit recording has no sign he told the instructor.
They came in high and fast. About 3.5 nautical miles out, trying to get down, he selected a mode that instead started a climb. He clicked off the autopilot and pulled the thrust levers to idle. That put the autothrottle into HOLD, a mode in which it does not control speed. The four letters appeared on both pilots’ displays. None of the three pilots recalled seeing them.
From the jumpseat, the relief first officer twice called “sink rate sir.” At 500 feet the speed had fallen to exactly the 137 knots they wanted, and a little lower the instructor said “on glide path sir.” But the thrust levers sat at idle and the jet was sinking too fast, which under Asiana’s procedures already called for a go-around. Nobody called one. At about 220 feet the four lights beside the runway all turned red: too low. The instructor said “it’s low.” The trainee said “yeah” and pulled the nose up. Without thrust, that could not fix it.
It was a training flight, not a test. Still, the trainee later recalled thinking that if the lights went to four red, he would fail the flight and be embarrassed. He also believed only the instructor, as pilot in command, could order a go-around. The instructor believed it was the trainee’s call. The NTSB said the trainee’s deference to authority likely played some role.
At 11:27:39 a chime sounded and an “airspeed low” caution appeared. The jet was at 124 feet and 114 knots, eleven seconds from the seawall. At about 90 feet the instructor said “speed” and shoved the thrust levers forward. NTSB testing found that a go-around started at 124 feet would likely have cleared the seawall. Below 100 feet, the airplane could no longer climb out in time.
The landing gear and tail hit the seawall short of the runway, and the tail broke off. Three passengers died and 49 people were seriously injured.
Afterward, the trainee told investigators that as long as the autothrottle was on, it would always keep the selected speed.