Years ago, there were stories about a software bug that caused F-16 fighter jets to flip upside down when they crossed the equator. When you first hear such a story, it’s bound to make you laugh; but I suspect that the fighter pilot didn’t think it was very funny. I haven’t been able to track down the details of this apocryphal story, but you can find a mention of it here and here; the original article was allegedly published in ACM Software Engineering Notes, Vol. 5, Number 2, in April 1980. But it doesn’t appear in the table of contents for that issue, and I haven’t yet been able to track down; if you are clever enough to find it, please send me a note so I can let everyone know where it is..

In any case, it appears that a similar software problem has appeared in a newer, state-of-the-art military plane: an article in today’s Slashdot, entitled “Software Bug Halts F-22 Flight,” says:

“”The new US stealth fighter, the F-22 Raptor, was deployed for the first time to Asia earlier this month. On Feb. 11, twelve Raptors flying from Hawaii to Japan were forced to turn back when a software glitch crashed all of the F-22s’ on-board computers as they crossed the international date line. The delay in arrival in Japan was previously reported, with rumors of problems with the software. CNN television, however, this morning reported that every fighter completely lost all navigation and communications when they crossed the international date line. They reportedly had to turn around and follow their tankers by visual contact back to Hawaii. According to the CNN story, if they had not been with their tankers, or the weather had been bad, this would have been serious. CNN has not put up anything on their website yet.”

All of which should remind us to be very humble: we have much better technology than we did in 1980, but we’re building much larger, more complex systems. And even though you would think that programmers would write their code to behave appropriately when a plane crosses the equator or the international date line, and even though you would think the QA people would remember to include this as part of their testing regimen, there are still some very unhappy pilots out there.