August 11, 2007: The U.S. Air Force pays close attention to what happens to commercial air freight aircraft. That's because, while 42 percent of U.S. Air Force aircraft are over twenty years old, over eighty percent of those freighters are. Operating aircraft this old is unexplored territory, because this is the first time in history that so many large, and fast, aircraft have gone on flying for so long.

The basic problem is that, despite constant maintenance and careful monitoring unexpected failures still occur with elderly aircraft. Nothing that is cause for alarm. Older aircraft are grounded if any unexpected failure seems imminent. While that just about eliminates these aircraft having fatal failures while in the air, it also makes older aircraft less available for service. But so far, it's been more cost effective to keep the old birds flying, than to buy new ones. Even growing fuel economy problems can be solved by installing new (more fuel efficient) engines.

While this is fine for transports (including the decades old KC-135 aerial tankers), it doesn't work so well for fighters. These aircraft do things transports don't, mainly violent maneuvers that induce stresses transports never have to put up with. What to do?

Air forces that can afford it, buy new fighters. But this is very expensive, costing $30-$80 million each (not even counting really high end aircraft like the Eurofighter or F22). A more attractive proposition is upgrading older fighters with new radars and long range missiles. This enables you to shoot down enemy fighters before they get so close you have to engage in violent maneuvers.

Many air force generals are simply being practical, and only getting as much aerial combat power as they need, taking into account what the neighbors, or any other likely foe, has. That attitude has resulted in a sharp drop off in jet fighter purchases in the 1990s. With the Cold War over, many nations no longer had any justification for buying expensive new jet fighters. Thus American fighters averaged about eight years old at the end of the Cold War, but has since climbed to nearly twenty years old. Thus the U.S. Air Force is anxious to get lots of new aircraft into the air, before there are some nasty surprises, because of the unpredictable way jet fighters age.