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)
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.