The U.S. Air Force is testing new drugs to cope with pilot fatigue. A major problem in modern warplane operations is pilot fatigue. This is particularly the case in the U.S. Air Force, which often sends aircraft out on missions that can take 12, 24 or more hours to complete. Actually, the problem is an old one, dating back to World War II. Then, as now, the cure has been dextroamphetamine (speed). Air force pilots have come to call this drug go pills, and they are basic equipment for pilots who operate long range aircraft. But one problem with the go pills is that they make some pilots more aggressive. For heavy bomber and transport pilots, this is not much of a problem. But for fighter pilots it can cause some errors in judgment (as with the F-16 bombing Canadian troops in Afghanistan two years ago.) So the air force is testing new drugs. One that recently went through some extensive tests is Modafinil (sold as Provigil). This stuff is described as a mood-brightening and memory-enhancing psychostimulant which enhances wakefulness and vigilance. It sounded promising, and the tests showed that pilots that took Modafinil saw their performance degraded 15-30 percent, versus 60-100 percent for those who took nothing at all after 24 hours of being awake. These tests had pilots in simulated cockpits for up to 37 hours, and performing realistic flight chores periodically (which were measured, producing a rating for pilot performance). While the Modafinil did a pretty good job, the dextroamphetamine was still a bit better. So the air force is making Modafinil available as an acceptable alternative to dextroamphetamine, particularly for fighter pilots (who might need their moods brightened, in addition to being kept awake.) Pilots were also warned that Modafinil often works without users being aware that they are cranked (as one tends to be when taking speed.) So the search for the perfect go pill continues.