On Saturday, the 6th of July, 2013, an Asiana Airlines flight from Seoul crashed on landing at San Francisco airport, hitting the sea wall in front of the runway.
Two passengers were killed, more than 160 were injured, and dozens of frightened passengers and crew had to evacuate the heavily damaged aircraft before it was engulfed in smoke and flames.
So what caused the Asiana Airlines crash? And what could have been done to prevent it?
Asiana Airlines Crash: What Was the Cause?
There has been speculation that the cause of the crash was that the aircraft was travelling at a speed significantly below its required approach speed.
According to Deborah Hersman, Chairwoman of the U.S. National Transportation Safety Board, information collected from the plane’s cockpit voice recorder and flight data recorder indicated that there were no signs of trouble until seven seconds before impact, when the crew tried to accelerate.
Apparently, a stall warning sounded four seconds before impact, and the crew tried to abort the landing and initiate what is known as a ‘go around’ manoeuver (missed approach) just 1.5 seconds before crashing. Hersman said that “air speed was significantly below the target airspeed.”
Why Would This Cause the Aircraft to Crash?
All aircraft from small four-seater piston aeroplanes to massive jet airliners rely primarily on lift in order to fly. Airflow over the wings produces lift, which means the engines must produce enough power for the aircraft to travel fast enough to produce the required lift to keep the plane aloft.
Every aircraft has a stated speed for approach to landing. If the speed is reduced too much below this, there will not be enough lift to keep the plane in the air. If this happens the wing ‘stalls’. This is not at all the same as an engine stall in a car – what it means is that the lift over the aircraft becomes too low, and the aircraft begins to literally fall out of the sky.
All aircraft have a ‘stall warner’, usually an auditory signal, which warns the pilot to increase speed to prevent a stall. If the speed isn’t increased, the aircraft will crash.
Decoding Science. One article at a time.