The mother of the last KC-135 pilot has probably not yet been born.

So says former Air Mobility Command (AMC) chief Gen. Duncan McNabb, who led the U.S. command that oversees the airlift, refueling tanker and aeromedical evacuation aircraft from 2005-07. He now heads the Transportation Command, which includes ground cargo and sealift.

As a result of a series of bad oversight decisions by the Pentagon and Congress, procurement mismanagement and politicking on the part of would-be tanker contractors and lawmakers eyeing work for their districts, there appears to be no more clarity now on the way forward to modernize the fleet—whose average age is 45 years—than there was in 2001.

Meanwhile, at AMC, planners are wrangling with how to keep the KC-135s flying until as late as 2043. “We have tremendous maintainers and air crews, so I am not concerned in the next few years about how the KC-135 performs,” says Gen. Arthur Lichte, outgoing AMC chief. Lichte points out that maintenance crews sometimes work 7 hr. for every hour of KC-135 flight. Gen. Raymond Johns will replace the retiring Lichte this year.

Refuelers—critical elements of U.S. military strategies—are needed to quickly deploy combat aircraft overseas in the event of war. To sustain such operations as those in Iraq and Afghanistan, tankers enable fighter and intelligence aircraft to fly beyond the limits of their fuel tanks. Additionally, future war plans, especially those addressing threats from North Korea and China, rely heavily on tankers because of what strategists call the “tyranny of distance” in projecting forces across the vast expanse of the Pacific Ocean.

However, without new tankers to replace old ones, anticipated costs to continue the mission are growing dramatically. “Every year we don’t get tankers, it is costing us $55 million right off the top,” Lichte says. “When you get out to about 2018 and 2020, what started out as about $2 billion a year to maintain the KC-135 fleet goes all the way up to $6 billion.”

This spike in maintenance charges has AMC planners worried. U.S. Air Force officials anticipate spending about $3.5 billion per year from its procurement account buying new KC-X tankers for the foreseeable future, and this amounts to 12-18 aircraft per year with an estimated per unit cost of $200 million. This means a significant portion of the Air Force’s budget for the next couple of decades will be designated solely for the refueling mission. Assuming $6 billion in annual maintenance cost for the KC-135 fleet, plus another $3.5 billion to buy KC-Xs, the yearly cost of the refueling mission is projected to exceed the total annual budget of the Missile Defense Agency at its peak during then-President George W. Bush’s administration.

The increase in projected maintenance costs is attributable mostly to planned improvements to keep the fleet safe. Dave Merrill, AMC’s deputy director of strategic plans, programs and requirements, says two areas of concern are behind that estimate. “We know that there will be needed depot-level maintenance actions on fuselage skin and wiring,” he says, noting that this amounts to a “mountain of requirements” late in the next decade.

“Obviously, the biggest fear is a catastrophic failure,” Lichte says. “We want to make sure we prevent that. And, so we continue to do everything we can to make sure don’t have an Aloha Airlines where the skin peels back or a TWA 800 [type incident] where frayed wires cause an explosion in the fuel tank.” Lichte says the “unknowns” of flying a fleet of half-century-old aircraft worry him.

Corrosion management remains a primary focus for the KC-135 fleet. As much as 30-50% of the programmed depot maintenance addresses corrosion issues, AMC officials say. In total, aging-related costs are expected to add at least $17.8 billion to the price of maintaining the KC-135 for 40 years. This is the equivalent of about five years’ worth of KC-X procurement at the $3.5-billion annual estimate.