Reports are in that the pilot of Asiana 214 tried to abort the landing just 1.5 seconds before the crash at San Francisco International Airport on Saturday. The subsequent crash-landing resulted in the death of two teenage girls from China and wounded 168 passengers, eight of which remain in critical condition.
Investigators reported that the plane descended at a dangerously slow speed, which resulted in the pilots running out of time to correct their approach. National Transportation Safety Board Chairman Deborah Hersman released a statement on Sunday confirming that the plane was traveling significantly below its target speed of 137 knots. The information was gathered from initial data in the aircraft’s cockpit voice recorder and flight data recorder.
While there has yet to be a definitive ruling on the cause of the accident, pilot error is being looked at as a factor. Lee Gang-kuk, the pilot during the crash, had only 43 hours flying the Boeing 777; however, he did have close to 10,000 hours total flying experience. It was also his first attempt at landing at SFO with a 777, though he had successfully landed a Boeing 747 at SFO. Gang-kuk did have an experienced pilot assisting him with the landing: Deputy Pilot Lee Jeong-min had 12,390 hours flying time with 3,220 on the 777. Also onboard were two additional pilots who had been rotating shifts during the 10.5 hour flight from Seoul.
Right now, National Transportation Safety Board (NTSB) investigators and South Korea Transportation Ministry workers have interviewed all four pilots. Korean officials caution that we can not assume pilot error until there is a complete report evaluating all data and evidence.
The Associated Press reported that a pilot had stated that the instrumental landing system (ILS) for the runway was shut down. When functioning properly an ILS is used to set up a 3-D glide scope for pilots to follow in setting up a landing.
A commercial pilot of 28 years, who currently flies for a major U.S. Airline, noted the potential for pilot and mechanical error in the approach:
Landing at SFO is a walk in the park. It’s a super easy airport to land at and doesn’t require a difficult approach. In a perfect world, for a perfect FAA landing, you touch down with 1000ft left on the runway…and at SFO you can have that.
There are a couple possibilities on landing – ideally, you want to come in “super dirty,” meaning you have full flaps, gear down and 60-70% power in your engines. Jet engines have a lag time in response coming from idle, so having them fired up ensures any move you make results in an instantaneous response. Coming in idle doesn’t mean you’re in an awful situation, it just means that say 5 miles out you were “hot” or too high. Normally from 5 miles out we want to be all dialed in – super dirty. On a 3 to 1 glide slope, meaning for every mile out you’re 300 feet off the ground — you drop about 800 feet a minute. If you are too high, bringing the engines to idle allows you to glide the plane down like a space shuttle, which lands without engines using their own energy. Now you can descend 4000 – 5000ft a minute, until you get back to that normal glide slope. You’re correcting, and everyone in the cockpit knows you’re trying to get it down.
If you’re not on it, textbook and regulated response is to go around again, but it’s hard to make yourself do it knowing you can get it down…you can visualize that slope and find it again. If it was pilot error vs mechanical error, not finding that slope in time seems like a possibility.
It looks like the airplane was actually low and very slow….like it was stalling. I have no idea how the pilots wouldn’t correct that if everything was working.
With 4 pilots you get a break to sleep, but depending on the order of your break, you might not be able to sleep more than an hour or two. You’re flying all night and your body clock is upside down. You can feel your brain wanting to go to sleep.
For more information regarding this incident, check out Peter’s blog, What We Know & Don’t Know About the Asiana 214 Crash.
By Lily J. Kosner for Peter Greenberg.com