Thursday, November 21, 2013

How does a plane land at the wrong airport?

A good friend sent me a story from CNN about a 747 that landed at the wrong airport last night and asked how it could happen. The short answer is that it's not as hard as it seems, especially under the circumstances.

For a while now, when teaching about situational awareness, I have used the example of this C-17 Globemaster crew that landed at Peter O. Knight airport in Tampa instead of MacDill Air Force Base where they had intended:


Thanks to the 747 crew, I have a second example of how easy it is to chase the wrong patch of concrete. Keep in mind that both of these examples happened to professional crews using modern equipment and avionics. (Update: USA today has a short rundown of how many times this has happened in just the last 10 years.)

When I started to read the story my friend sent me, I originally thought, "Oh, they must have landed at Mid-Continent instead thinking it was McConnell AFB. Both of them have long parallel runways heading in the same direction." I've been to Mid-Continent (center-left underneath the "WICHITA" below) and I remember when I was looking at the sectional chart during my flight planning I made a mental note as to how much McConnell looks like Mid-Continent and to double-check I was pointed at the right one once I got there.

Chart from vfrmap.com
Both of these incidents had several things in common:
  1. crew going to a military, towered field lands at a non-towered field
  2. runways in similar configuration
  3. you actually heard about it happening
Regarding (1), until I had a chance to spend a lot of time in a control tower taking students for visits to one, I wondered how the person in the tower wouldn't have gotten a wee bit concerned about why the plane's altitude was so much lower than one would expect if they were landing at the correct airport. After seeing how they operate and getting a better understanding of their place within the system, I can see how such a thing could be missed.

Tower controllers have lots of other things they're doing at the same time. The usual depiction of controllers as people staring at a radar screen unblinkingly with nothing else in front of them is only true of either center controllers or approach controllers. You've seen these time after time, including in the funny but underappreciated movie Pushing Tin with John Cusack, Billy Bob Thornton, and Angelina Jolie:



That stereotypical image isn't even remotely true of tower controllers because their job isn't to get aircraft from Point A to Point B. The aircraft has already made it almost to Point B and their job is to sequence them in line with other aircraft that may already be landing (or waiting to take off), and it's up to the pilot to actually land it. They might notice if the aircraft's blip (called a data block) drops off the radar early, but in this case they were in an area where radar coverage goes all the way to the ground (as the dotted magenta line surrounding AAO, the airport the 747 crew landed at, shows above). If the aircraft is in distress or the pilot tells the tower controller on initial contact that they're a student pilot, the controller will watch the display very closely, but for a routine flight flown by a highly experienced crew (no one just hops into one of the front seats of a 747 without thousands and thousands of hours) in the middle of the night with no other traffic around, its very easy to see why this wouldn't be noticed. After all, controllers can't fly the airplane, and they expect the people who are to do the job right.

Regarding (2), the only thing that surprised me about the C-17 in Tampa is that it hadn't happened even earlier or more often. Peter O. Knight looks much like a miniature version of MacDill, and it is directly in line for final with one of MacDill's runways. This is very similar to an environment the 747 crew was put in, as you can see by this sectional chart excerpt:

Chart from vfrmap.com

In the Wichita chart excerpt above, I drew a cyan line connecting the two to emphasize how both runways go in the same direction and line up with the flight path of the 747 almost perfectly. At any time, but especially at night, these airports wouldn't look all that different from one another. Since I don't have the time to hop in the plane and fly the 700+ miles to take a good, real picture, here's a view of what the arrangement looks like at night in Microsoft Flight Simulator X from an altitude and distance they were likely to be at:

Click image to embiggen.

There's the airport they landed at, from 4,000 feet and 10 miles out, which is my best educated guess at where they were. (Update 11/22: I dug up the flight's track log on FlightAware and that was one outstanding guess. That's pretty close to where they were at one point.) Did you notice the darker patch in the background? Yeah, they probably didn't either. That's because they were in the right vicinity, the heading was about right, the altitude was about right, and there was an airport right about where one should be. With that in mind, once the pilot flying saw the airport, his mind locked on to it and he concentrated only on flying safely down to it. Once the airport is in sight, even GPS or the FMS gets ignored, because the point of navigation systems is to get you to the point where you have the airport in sight.

The concentration required on approach forces the mind into a sort of tunnel vision. This isn't something that more training would fix, and it's not something only a "stupid" pilot would do: this is a basic, unavoidable fact of human nature and the human brain. Screening out distractions and focusing solely on the task at hand is an excellent skill and one of the things that makes a good pilot a good pilot. Unfortunately, in this case, one of the "distractions" was the airport he actually meant to land at.

I've had flight students take me to the wrong county before, even when there is no other airport within 20 miles. That's because I sprung an "emergency" diversion on them right in the middle of their nicely-planned cross-country flight, they focused on an airport that they thought was the one I told them to divert to, and concentrated on flying to the airport they saw. It wouldn't be hard to go to the wrong one when there are 4 airports within 10 miles that all look a lot alike, as is the case with the 747 crew here.

Regarding (3), this doesn't happen every day or every month, but it does happen plenty of times that you don't hear about. Many general aviation pilots have picked the wrong airport, and small regional airliners have done the same on several occasions. The difference with them is that because they're much smaller aircraft, they simply blush, taxi back to the ample runway, and take off again without anyone ever being the wiser. (Except in the case of the regional airliners, because the onboard ACARS or similar system automatically reports landing and takeoff events to the airline office, so those pilots might get a bit of a raised eyebrow from the company without making headlines.)

Another friend pointed out this incident from NASA's Callback bulletin from October 2004 called "Lost, Alone, and in the Dark" that you probably didn't hear about because it didn't make the news:
I preflighted the plane for a return flight to [another airport in Wisconsin]. The lighting on the instrument panel seemed faint, but the airport ramp was well lit. I adjusted the rheostat on the panel and departed. Once aloft, I could not easily read the instruments. Relying only on the compass, I became lost. I could not read the clock and lost track of time. After searching for an airport to put the plane down, I saw one with a runway open. I saw a plane approaching and, maintaining a safe distance, followed it in and landed. I took the first taxiway off the runway and shut down. I had not declared an emergency and was not in contact with the tower. It was O'Hare.

In the end, the Air Force concluded its investigation of the C-17 incident by stating the cause as pilot fatigue. While it will be quite some time before the facts of this current incident come out, I suspect that in the end the final cause will boil down to a simple matter of human imperfection. It's easy to second-guess and Monday morning QB, but in reality good pilots are always trying to learn from the mistakes of others (you can't live long enough to make all of them yourself) without copping an attitude of, "That would never happen to me." That's a lesson that—like so may others—transfers well from the cockpit to everyday life.

2 comments:

  1. Thank you so much! When i saw the story I knew you would set me straight. I'm glad it inspired you to share your thought with everyone.

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  2. I'm glad I could help. You gave me another thing to put in the instructional tool bag. I've found that hours of lectures on situational awareness or other aviation subjects is nowhere near as effective as five minutes of "This is what happens when you don't pay attention to [insert subject here]" stories.

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