In case you were wondering.... (Updated)

... the Northwest Airlines flight that apparently "missed" the Minneapolis-St Paul airport today and overshot it by 150 miles did not make an ordinary mistake, like missing Exit 32A on a busy freeway and having to get off on Exit 32B.This is more like ... well, it's hard to think of a comparison, because it's pretty startling.

Once when I was flying westward toward the Rapid City airport in South Dakota, I found myself lining up 25 miles away instead with the much bigger runway of Ellsworth Air Force Base nearby. I must not have been the first one to do so, because the controller said in a routine way, "What you're probably heading for is Ellsworth. You want to turn your head ten degrees to the left and look for a little airport that's closer. That's where you want to go." This was embarrassing enough, and it was just my wife and me, not a bunch of paying passengers. (Below, Google Earth's view of what caused my problems. The runways have similar orientation, and Ellsworth is the first one you see from a distance. And this is from straight overhead! I was looking from a slant, into a setting sun, from a relatively low altitude, way off in the distance. It's a miracle I saw either of them!)

In contrast, from the air you really cannot miss a big, busy, international airport. It's unlike anything else you see -- especially when controllers are talking you every step of the way, as they are required to with airliners. Rather, I guess you can miss it, but it's a surprise.

Glad everyone is safe. Will be interesting to hear the pilots' account. I have my own hypotheses, but it's fairer to wait.

UPDATE: To avoid being coy about my "hypothesis," it's hard to imagine how this could have happened if the pilots were awake. There is too much going on in the last 45 minutes of a flight -- with procedures for arrival, approach, and landing, many checklists -- just to be "distracted." So most likely either they both fell asleep in the normal sense or, weirdly, were both disabled in a way they then recovered from. After a cockpit crew on Go! airlines fell asleep for fifteen minutes in Hawaii last year while their plane was headed out toward the open ocean, one of the Honolulu Star-Bulletin's readers offered this possible explanation:

"Aliens I say. They took the pilots to their spaceship, then put them back in the plane. They were gone for 2 weeks, but only 15 minutes Earth time." 

Bonus analysis point: on top of the Colgan crash in Buffalo early this year, plus that previous Hawaiian sleeping-pilots problem, we are bound to see more serious political attention to the question of work rules, fatigue, pilot training, etc under the new operating realities of the airline industry. Thanks to M. Griffith for the Go! tip.