But at that height, the pilots are vulnerable to altitude sickness and must wear spacesuits and astronaut-style fishbowl helmets. An hour before taking off, they are put on a regimen of pure oxygen to reduce the amount of nitrogen in their blood.
In a worst-case scenario, a pilot’s blood could boil at peak altitude.
Pureed, meal-in-a-tube versions of everything from sloppy joes to apple pie are supplied to the pilots but must be sucked through straws.
“Our main concerns are hydration and decompression sickness,” said the pilot who made the landing during the tour and who asked to be identified only as Maj. Carl. “It’s extremely hard to fly.”
To make the plane lighter, and thus able to fly higher, two “pogos” — wheel gear fixed to either wing — automatically detach when it roars off the runway, meaning that when it comes back down the pilot must land on only two sets of wheels along the fuselage.
At Osan, U-2 pilots in white Pontiac G8 “chase cars” race down the runway at speeds of more than 120 miles per hour to meet each landing and guide the pilot down.
They estimate the plane’s distance from the ground in feet and radio that to the pilot — “Five … five … four … three … three” — until the plane is brought to a stall with about 2 feet to go and essentially drops down to the ground.
The Air Force has 31 U-2s in active duty. NASA operates two more.
Though detachments also are located in Cyprus and southwest Asia, the key role the aircraft plays in monitoring North Korea is keeping the legendary plane from the chopping block.
The plane, which took crucial photos of the Soviet buildup that touched off the Cuban missile crisis in 1962, has proved to be surprisingly versatile. The Air Force has given it a $1.7 billion makeover since 1994, transforming it into an essentially new aircraft in all but name.
Its sensors can function day or night in any weather. The data it gleans can be relayed via satellite link in near real time to troops on the ground.
“Most of the aircraft are really quite young,” the U-2 commander said. “The ones we are flying here are from the 1980s. They have been re-engined, rewired, new cockpits, advanced avionics. Of course, the sensors are continuously being updated. This airplane is cutting-edge, absolutely.”
Still, the Air Force has hinted for years that the U-2’s days are numbered.
It was scheduled to be phased out by 2015 in favor of the Global Hawk, which was used extensively in Iraq and Afghanistan. But the U-2 gained a reprieve last month when the Air Force decided that replacing it with the drone would be too expensive.
Aviation analyst Loren Thompson of the Arlington, Va.-based Lexington Institute, said retaining the U-2 indicates the Air Force is more concerned with North Korea — and cost-saving — than monitoring areas farther away.