Federal investigators are describing what appears to be a lack of air speed from the Asiana Airlines flight that crash landed at San Francisco International Airport Saturday.
Stressing the investigation is still in its early stages, Deborah Hersman, the head of the National Transportation Safety Board, said just before the crash, one of the crew members is heard on the plane’s cockpit voice recorder calling for more air speed:
“ A call by one of the crew members to increase speed was made approximately seven seconds prior to impact.”
According to Hersman, one of the crew apparently realized the plane did not have enough power or was about to stall, and called to abort the landing, also known as a “go-around”:
“A call to initiate a go-around occurred 1.5 seconds before impact.”
During the final seconds of the flight, the flight data recorder showed the Boeing 777’s air speed was “below target” as it approached the runway. This caused one of the plane’s warning devices to activate just four seconds before the crash.
The warning device, or stick-shaker, provides a warning to the pilots that the aircraft is about to stall.
At about this time, Hersman said the plane’s throttles were “advanced” and the engines appeared to have responded normally.
Hersman also said visibility was clear and there were not reports of strong winds, wind shear or any other adverse conditions at the time of the crash:
“(The landing) appeared routine until the controllers noticed the aircraft hit the seawall.”
Despite the information gathered from the cockpit voice recorder and the flight data recorder, Hersman said investigators have not determined what caused the crash.
Investigators still must examine the engines, including electronic modules that record engine problems, as well as interview survivors and review the debris field left by the skidding plane.
They will also interview crew members, something they hope to do in the next few days.