What they don’t yet know is whether the pilot’s inexperience with the type of aircraft and San Francisco’s airport played a role.
Investigators looking into the jetliner’s crash in San Francisco, which killed two young girls and sent more than 180 to hospitals, said they were also focusing on whether the airport or plane’s equipment also could have malfunctioned.
The South Korea government announced officials will inspect engines and landing equipment on all Boeing 777 planes owned by Asiana and Korean Air.
San Mateo County Coroner Robert Foucrault said he was investigating whether one of the two teenage passengers killed actually survived the crash but was run over by a rescue vehicle rushing to aid victims fleeing the burning aircraft.
Remarkably, 305 of 307 passengers and crew survived the crash and more than a third didn’t even require hospitalisation. Only a small number were critically injured.
Investigators said that the weather was unusually fair for foggy San Francisco. The winds were mild, too.
During the descent, with their throttles set to idle, the pilots never discussed having any problems with the plane or its positioning until it was too late.
Seven seconds before the Boeing 777 struck down, a member of the flight crew made a call to increase the jet’s lagging speed, National Transportation Safety Board chief Deborah Hersman said at a briefing based on the plane’s cockpit and flight data recorders.
Three seconds later came a warning that the plane was about to stall.
Two-and-a-half seconds later, the crew attempted to abort the landing. The air traffic controller guiding the plane heard the crash that followed almost instantly, Hersman said.
While investigators from both the US and South Korea are in the early stages of an investigation that will include a weeks-long examination of the wreckage and alcohol tests for the crew, the news confirmed what survivors and other witnesses had reported: a slow-moving airliner flying low to the ground.
“We are not talking about a few knots” difference between the aircraft’s target landing speed of 137 knots, or 250km/h, and how fast it was going as it came in for a landing, Hersman said.
Pilots normally try to land at the target speed, in this case 137 knots, plus an additional 5 more knots, said Bob Coffman, an American Airlines captain who has flown 777s. He said the briefing raises an important question: “Why was the plane going so slow?”
The airline said the pilot at the controls had little experience flying a 777 and was landing one for the first time at that airport.
Asiana spokeswoman Lee Hyomin said Lee Gang-guk, who was at the controls, had nearly 10,000 hours flying other planes but only 43 in the 777, a plane she said he still was getting used to.
Another pilot on the flight, Lee Jeong-min, had about 12,390 hours of flying experience, including 3,220 hours on the 777, according to the Ministry of Land, Infrastructure, and Transport in South Korea. Lee was the deputy pilot, tasked with helping Lee Gang-guk get accustomed to the 777, according to Asiana Airlines.
Two other pilots were aboard, with teams rotating at the controls.
The two teenage Chinese victims were best friends and promising students, reports said. Wang Linjia, 17, and Ye Mengyuan, 16, studied together at high school in Jiangshan in the province of Zhejiang, the Beijing Morning Post said, citing Ye’s relatives, who speculated they may have sat in the same row on the plane.
A picture of Wang was stuck in a hedge outside her school, surrounded by flowers.