July 8, 2008: An investigation concluded that the crash of a U.S. F-16 last March, during an air combat training exercise, was due to the pilot blacking out from the high g-forces generated by tight turns. This has been a growing problem over the last half century, as aircraft become more powerful, and capable of more powerful maneuvers.

An additional problem is that new helmets (the JHMCS, or Joint Helmet Mounted Cueing System) weigh 4.3 pounds, which is about fifty percent more than a plain old helmet. That extra weight may not seem like much, but when making a tight turn, the gravitational pull (or "Gs") makes the helmet feel like it weighs 38 pounds. In response, the U.S. Air Force introduced a new neck muscle exercise machine in air force gyms frequented by fighter pilots, because you need stronger neck muscles to deal with the heavier helmet. For decades now, fighter pilots have had to spend a lot of time building upper body strength in the gym, in order to be able to handle the G forces. Otherwise, pilots can get groggy, or even pass out in flight, as well as land with strained muscles.

Accidents like the one last March remind all pilots how real this danger is. The dead pilot was a former enlisted airman, who qualified for officer training and flight school. Training for new pilots has always been the most dangerous period of a pilots career. As you spend more time in the air, you learn more about how to handle the high g-forces, and how much you can endure before losing consciousness.

The air force has been working on flight control software that would quickly take over if it sensed the pilot had blacked out, and return the aircraft to level flight. But UAVs may replace manned fighters before that lifesaving blackout software shows up.