Originally posted at The Sky Behind Me blog January 14th 2014.
Oooops… Recently (and once again) a commercial airliner landed at the wrong airport. Southwest flight #4013 from Chicago enroute to Branson Missouri landed at a nearby college airstrip instead. This is reminiscent of a cockpit mistake in a similar incident many years ago in Columbus Ohio, my home town. In that episode, a Trans World Airlines 707 landed at Ohio State University’s Don Scott Field, fifteen miles northwest of Port Columbus, the plane’s scheduled destination. Why does this continue to happen? What can prevent it? Here’s one reason it happens, and one way to lower the possibilities.
Planes land at different airports a lot more often than we might think. Full disclosure, it happened to me once, many years ago, when I landed at Akron (Ohio) Municipal airport believing I was on approach to Akron-Canton. I was operating a single-pilot aircraft, weather was clear, with unlimited visibility and I’d never landed at either airport. Oddly enough, one of the reasons pilots land at the wrong place is that weather conditions are clear, with no restriction to visibility, and yes, they’re unfamiliar with the field. The weather factor may seem counterintuitive: in clear weather, pilots ought to be able to see where they’re headed, and land at the right place. The issue here is guidance, and the Air Traffic Control system’s limited amount of it in clear weather. The ATC system is designed to separate planes in the national airspace system, and to direct pilots into landing airports. The bulk of this activity is done for reasons of poor visibility. In clear weather, the ATC system turns many of the orientation and landing tasks back over to pilots in cockpits, clearing them for “visual approaches” to their destination fields.
Runways are built with prevailing winds in mind. Across the country, when runways are built, routine winds determine which direction the asphalt is laid, because planes need to take off and land into the wind as much as possible. If prevailing winds are from the west, the runway is constructed east-west, to optimize takeoff and landing. Thus, all runways in a given geographic area are oriented much the same. The FAA stipulates color, placement, intensity and operation of runway lighting, to maintain uniformity. Thus, all airports look alike at night, especially in clear weather. And they point the same direction. When a pilot is cleared for a visual approach into an airport, ATC releases that pilot from its guidance and the pilot takes over. If the weathe were poor, visibility limited, ATC would follow the plane all the way to the ground. So with SouthWest flight 4013, it’s speculation of course, but it appears that if weather had been an issue, visibility bad, the pilots would have landed at the right airport.