Killer at 70,000 Feet

The occupational hazards of flying the U-2

A pilot takes a self-portrait aboard the U-2. The Air Force is retrofitting the airplane’s cockpit so it is pressurized to a more comfortable 15,000-foot equivalent. (Lt. Col. (Ret.) Jeff Olesen)
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Kimbrough was one of the first U-2 pilots to experience central nervous system DCS, also called Type II DCS. In the following months more cases cropped up. The Air Force took notice, but because flight doctors still didn’t understand exactly how and why DCS affects pilots, they were slow to find ways of coping with the new threat. Air Force physiologists pored over Kimbrough’s equipment, trying to find out why the normal pre-breathe precautions had failed. Pilots were told to pre-breathe for a longer time, but they weren’t given more rest between flights. The wars in Iraq and Afghanistan continued, the missions stayed long, and pilots continued to get sick.

According to Jersey, the Air Force’s attitude toward DCS changed significantly in 2006. He thinks the squadron was overconfident in the attention they were paying DCS prevention, “until Kevin Henry really woke everybody up.”

Henry had already vomited into his pressure-sealed helmet by the time his squadron commander got on the data link, the U-2’s upgraded version of a radio. Henry had to take off the helmet so he could see, exposing his body to the much lower pressure in the cabin and further accelerating the development of symptoms. He tried putting coordinates for his home base into the autopilot, then realized he had forgotten how to use the device. Lieutenant Colonel Dave Russell, the squadron commander, had just gotten out of bed back in California, and began to talk Henry through the process of getting home.

Over the next three hours, with Russell’s guidance, Henry managed to steer his U-2 toward a friendly air base in the Middle East. His short-term memory was gone; all he had to rely on was the muscle memory he’d developed as a young trainee. “I could still do basic airmanship stuff,” he says, “you know, push forward on the yoke and the houses get bigger.”

But even simple tasks were getting harder. As Henry neared the runway, Russell told him to put the landing gear down. When he reached for the handle, it wasn’t there. He’d developed several blind spots in his vision, and had to grope around in the area where he knew the handle should be.

“Nothing made any sense,” he says. “I had horns and lights going off, and I go, That means something important—I can’t remember what that light means.”

Henry doesn’t remember the last 45 minutes of the flight. People watching from the ground later described to him the way he plummeted toward bunkers and hangars, sending ground crews running. When it became clear that Henry didn’t know what to do next, a pair of Mirage jet fighters from the local air force helped to guide him down toward the runway.

After a number of unsuccessful landing attempts, Henry blacked out again, this time while headed straight for the ground.

“It was almost like it faded in,” he says about the scene in front of him. “And there was a bunker in the middle of the windscreen. And just instinctively [I] did a traffic pattern stall recovery. You know, stuff that you learn from day one flying.” An adrenaline rush momentarily cleared his head, and he pulled the airplane around and landed it in the middle of the runway. When the U-2 came to a stop, pilots on the ground had to drag Henry’s limp body from the cockpit.

He wasn’t out of the woods yet. Nitrogen gas had already ravaged his body; the treatment for people suffering from DCS is usually administered much earlier in the process. He was placed in a hyperbaric chamber, a pressurized room where a gradual shift from low to high pressure gives nitrogen gas time to dissolve back into the blood. For several days, he was in and out of the chamber, still in a haze and unable to remember simple things, like how to fasten a seat belt. Despite having been close to death, Henry recovered fully from his physical symptoms. The only visible evidence of his ordeal are scars that the bubbling nitrogen left on his skin.


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