WICHITA - In the skies over Kansas at 21,000 feet on a recent morning, two McConnell Air Force Base crews were on an air-to-air refueling training mission in KC-135 tankers.
The Stratotankers - often called "gas stations in the sky" - fly just 50 feet from another aircraft when they offload fuel.
"It's basically a ballet act," Lt. Tim Hickman, a KC-135 navigator, said from his post inside the cockpit.
On this day, however, a hydraulic fluid leak would not allow the boom to operate properly. That part of the training mission was scrubbed.
The problem typifies a growing issue with the Air Force's tankers: More and more, the fleet shows its age.
Plans to replace the planes have been delayed by contract disputes and political squabbling.
When the fleet will be replaced - and by whom - will have a huge impact on Wichita.
Boeing and Northrop Grumman are battling for an initial $35 billion aerial refueling contract. A Boeing win could mean jobs for Wichita.McConnell Air Force Base, which has a $408.8 million economic impact on the community, is the largest tanker base in the world. By September, the number of tankers there will grow to 48.
McConnell's tankers are flown by the 22nd Air Refueling Wing and the U.S. Air Force Reserve 931st Air Refueling Group.
The KC-135s were built in the late 1950s and early 1960s, during the Cold War.
McConnell officials compare the fleet to a 1957 Chevy.
"At some point,'' said Col. James Vechery, commander of the 22nd Air Refueling Wing,". . . you make the decision to replace it.''
A force multiplier
Tankers are critical to the military. In 2008, they completed more than 18,000 missions and offloaded 1.1 billion pounds of fuel.
"Nobody over Iraq or Afghanistan would be flying or transporting people or cargo or patients if it wasn't for the tanker," said Capt. Tiffany Taylor, a KC-135 pilot at McConnell, who at 29 is two decades younger than the aircraft she flies. "There's gas overhead for those guys 24-7.''
Tankers keep fighter planes in the fight, get the wounded to care faster and allow air patrols to linger longer.
"Tankers are an absolute force multiplier," said Col. Edsel Frye, commander of the 931st Air Refueling Group.
When not refueling, they are used to haul cargo and crews, or for search and rescue, communications and medical evacuations.
Every hour of flight time requires seven to 10 hours of maintenance.
At McConnell, hundreds of personnel work every day to keep the tankers maintained and flying, and more than 1,000 people at Tinker Air Force Base in Oklahoma work toward that same goal.
"We're going to take care of business, no matter what," Vechery said. "We're getting it done."
However, he conceded, "It's harder to get it done."
Time is not on their side. Aircraft that old run into numerous age-related problems, said Loren Thompson, a defense analyst at the Lexington Group.
"The most common problem is metal fatigue, which requires things like the skins to be replaced," he said.
Corrosion problems are growing. And it's increasingly difficult to get parts and components. At times, maintenance crews have waited up to two years for parts, officials said.
McConnell officials worry that a major defect will surface and cause the entire fleet to be grounded.
"If we have to ground the whole fleet, where would we be?" Vechery said.
In the Middle East, the fleet's usage is high. Each tanker flies six to eight hours at a time refueling multiple aircraft, said Taylor, the pilot. The planes rest only four hours before another crew takes them up again.
They're flown in searing desert heat and subzero temperatures.
"That's a lot of stress on that old aircraft," Frye said.
KC-135 crews say they learn to expect problems.
"I've not met another KC-135 pilot or navigator who hasn't had some kind of . . . malfunction," Taylor said. "It's just another day in the life for 135 pilots."
A problem during a training mission in Kansas is not a big deal. Overseas, a problem can cause missions to be delayed and force hard choices.
"We have to figure out who needs the fuel the worst," said Master Sgt. Paul Jacobs, a boom operator at McConnell.
Even if a contract to revamp the fleet were in place today, it would take more than 30 years to replace the planes. That will keep some KC-135s flying past their 80th birthdays.
"The biggest challenge we have is to keep this airplane around," said Gaddis Gann, chief engineer for the KC-135 at Tinker Air Force Base's Oklahoma City Air Logistics Center. "No one's ever flown an airplane for 80 years."
Replacing the aerial refueling fleet is one of the Air Force's top priorities.
U.S. Defense Secretary Robert Gates has said he plans to try again sometime this summer to pick a contractor to build a replacement. That has proven difficult so far.
There's a fierce rivalry between Boeing and Northrop Grumman, which is teaming with the European Aeronautic Defence and Space Co. -the parent company of Airbus - for the contract, which could grow to $100 billion.
And there's heavy influence from members of Congress, especially those from Kansas and Washington, who point to the jobs that would be lost if Boeing is not the winner.
But congressional delegates from several Southern states say a Northrop Grumman-EADS win also will mean thousands of jobs for their states. Northrop and Airbus plan to build a new plant in Alabama to assemble the tankers if they win.
The replacement program has had many fits and starts.
A plan to lease tankers from Boeing was halted in 2003 after a top Pentagon procurement official, Darleen Druyun, went to jail on corruption charges; she had been accused of favoring Boeing, where she had accepted a job.
Boeing's chief financial officer, Michael Sears, was also sentenced to four months in prison. Boeing CEO Phil Condit resigned soon afterward.
Last year, the Air Force awarded a contract to the Northrop-EADS team, but the contract was overturned after government officials found that the Air Force unfairly penalized Boeing's smaller 767 aircraft for use as the tanker's platform.
In a new round of bidding, Northrop Grumman has said it would likely again offer an Airbus A330 as its base for the tanker.
Boeing has said it wants to see the contract guidelines before it discusses its bid.
In the last competition, Boeing said that its Wichita facility would become a finishing center for the tankers if it was the successful bidder, a move that would have meant 300 to 500 jobs.
A Boeing win also would have meant another 500 jobs for Wichita suppliers.
At Tinker Air Force Base, more than 1,000 people and 2.4 million square feet of space are devoted to KC-135s.
Every tanker comes in every four to five years for intensive nose-to-tail inspections and repair.
"We get into areas of the aircraft that nobody sees," said Gann, the KC-135 chief engineer.
The time the tankers spend there has increased from an average of 180 days two years ago to 241 days. One tanker recently stayed for 500 days, nearly a year and a half.
Last year, 12 tankers needed significant structural repair. Corrosion and cracking are common, Gann said.
The biggest challenge is "the uncertainty and variability we have to deal with," Gann said. "Every airplane doesn't have the same combination of repairs.''
And many of the parts that need to be changed were never meant to be replaced.
Replacing one particular fitting in the rear of a tanker, for example, means carefully jacking up the airplane, cutting through bolts and removing a section of the floor to gain access.
Currently, decades-old fuel bladders under the flooring are being replaced. The bladders have "patches on top of patches," Gann said.
One of the biggest problems is due to the materials and methods used in the 1950s to assemble the planes.
Each tanker was basically hand-built, relying on the knowledge and skill of the mechanics on the floor. But there are no detailed drawings.
At the time they were built, no sealant was used on metal overlaps or on steel fasteners, and there is a lot of spot welding on the tankers. That leads to corrosion, Gann said.
Today, tankers are repaired using the latest technologies and better, lighter-weight, noncorrosive materials. The tankers also have been revamped with new engines and avionics.
Getting parts can be difficult. The suppliers are diminishing. At times, parts must be custom-built.
"Whatever it takes, I'll figure out a way to keep them around," Gann said.
Despite the problems, Jacobs, the McConnell boom operators, has faith in the tankers.
"I'm never worried," he said. "I'm always confident it's going to bring me home."