The 12-hour flight marked the first international deployment of the F-22, which is destined to replace the aging F-15 Eagle as the Air Force's top fighter plane. But about a third of the way through the Feb. 10 flight, anomalies began affecting the Global Positioning System and communications links on the jets, Air Force officials say. While one pilot was able to contact prime contractor Lockheed Martin during the flight to try to fix the problem, the planes were nevertheless forced to return to Hickam Air Force Base in Hawaii. They forlornly had to follow the KC-135 aerial tankers that were to have refueled them during the trans-Pacific flight.
It turns out that despite its 1.7 million lines of computer code on board, there was nothing telling the jets what to do when they crossed the International Date Line. That sent their avionics into a electronic tailspin. GPS receivers on the planes use signals from orbiting satellites to determine their location, altitude and speed, and require precise time and dates to work. "The International Date Line is the imaginary line on the Earth that separates two consecutive calendar days," the U.S. Naval Observatory says on its website. "That is, the date in the Eastern hemisphere, to the left of the line, is always one day ahead of the date in the Western hemisphere... Without the International Date Line travelers going westward would discover that when they returned home, one day more had passed than they thought, even though they had kept careful tally of the days. This first happened to Magellan's crew after the first circumnavigation of the globe."
So, like the intrepid Magellan, the Air Force pilots were flummoxed by the time-space continuum. In the pilots' case, the problem was fixed within 48 hours when Lockmart developed a software patch. It's not much different from the one you've recently received so your computer can adapt to the earlier arrival of Daylight Saving Time.