DEFENSE - Aging tankers stay in air amid replacement bid - Boeing and Northrop vie for a huge contract as crews fly jets built with 1950s technology.

EDWARDS AIR FORCE BASE — Cruising at 35,000 feet above the Mojave Desert, Staff Sgt. Cy Eckhardt peered out the back of a KC-135 aerial refueling tanker and spotted the approaching F-22 fighter jet.

Using two joysticks attached to a cockpit-like panel, Eckhardt remotely lowered a long telescopic boom from the tanker's rear and gingerly guided it to a fuel receptacle behind the fighter jet's canopy.

"Appreciate you guys hanging out here. Need about 10-K," the F-22 pilot said to Eckhardt over the radio, signaling 10,000 pounds of fuel. If it were gasoline and not kerosene-like jet fuel, that would be enough to fill 100 cars.

"No worries," Eckhardt said last week before topping off the F-22, which had been tethered to the tanker for about five minutes as the two craft sailed along at a relatively leisurely 350 miles per hour.

For more than half a century, fighters, bombers and other military aircraft have been refueled this way as they've traveled great distances on missions. The flying gas stations and their capability to refuel aircraft in mid-air have been mainstays -- albeit less visible than other weapons -- in projecting U.S. military might overseas.

But the planes were built during the Eisenhower and Kennedy administrations in the late 1950s and early 1960s, long before many of their current pilots were born.

Now, they're showing their age and the Air Force has made replacing them its top priority, ahead of the traditionally prized fighter jets.

"There is a saying out there that 'you can't kick ass without tanker gas,' " Sue Payton, the Air Force's acquisition chief, said at a defense seminar recently. But "we have tankers that should be flying around with an AARP card."

The move to update the tanker fleet has led to one of the most intense competitions in a decade, pitting two of the nation's largest defense contractors against each other, Chicago-based Boeing Co. and Century City-based Northrop Grumman Corp. At stake is a contract worth $40 billion with the potential to grow to at least $100 billion.

"It could be the biggest purchase in the first half of this century," said Loren Thompson, defense policy analyst for the Lexington Institute.

The local effect is likely to be significant. Hundreds of suppliers in Southern California are aligned with one or the other or, in some cases, both.

Suppliers on the winning team could be making parts for the new tanker for two generations or more.