|Life-support team puts pressure on high-flying pilots
by Master Sgt. Michael A. Ward
380th Air Expeditionary Wing Public Affairs
3/24/2005 - SOUTHWEST ASIA (AFPN) -- People feeling too much pressure may say something like, "You make my blood boil." If high-flying U-2 reconnaissance aircraft pilots lose cabin pressure, their blood literally could boil.
U-2 pilots fly in the rarified atmosphere more than 60,000 feet above the earth, and a loss of cabin pressure could be fatal. For their safety at that altitude, they wear a space suit similar to the ones astronauts wear.
"The suit is their life," said Staff Sgt. Craig Hawley, launch and recovery supervisor of the physiological support division of the 99th Expeditionary Reconnaissance Squadron. "That's where we come in. We take care of the suits; we take care of the pilots."
"The pilots trust us to do this technical job, and they trust us to make sure we've made the right decisions and do everything correctly on the suit," said Staff Sgt. Shann Elmore, a physiological life-support technician.
The cabin of the U-2 is pressurized, and pilots could fly without wearing the 90-pound suit, Sergeant Hawley said. However, if depressurization did occur, they would be in deep trouble with nowhere to go and nothing to turn to.
"If the cabin pressure fails, a controller on the suit will inflate it to an atmosphere of about 35,000 feet," Sergeant Hawley said. "If that fails, a second system will inflate it to about 37,000 feet. As a last resort, the helmet will create an atmosphere of about 39,000 feet. That's a high altitude, but it's better than 63,000 feet where they can't survive."
At 63,000 feet, blood boils because there is not enough pressure to sustain oxygen in the blood stream, Sergeant Hawley said.
"The nitrogen comes out of solution and starts boiling in their system. Bubbles start floating to places like the heart, brain, joints and bones, and that's not good for them," he said.
Nitrogen causes decompression sickness, also known as the bends. As a precaution, high-flying pilots also breathe 100 percent oxygen for one hour before flight to try and rid the blood of most of its nitrogen, officials said.
The suit is also necessary because the cabin is pressurized to almost 30,000-feet.
"At that altitude they need pure oxygen from the helmet just to be coherent enough to fly," Sergeant Hawley said.
The three-layered suits are made of Nomex material.
"The suit has a comfort liner that makes the pilots feel like they are getting into a form-fitted sleeping bag," Sergeant Hawley said.
Although the suits are designed to inflate, they do leak. The physiological team tests the suits often to make sure the rate of leakage does not exceed parameters, officials said.
"Every time I fly high, I put my life in the hands of these technicians," said Maj. Cory Bartholomew, a U-2 pilot. "Their professionalism instills confidence. I've never once worried that the suit might fail."
The space suits come in about 12 different sizes. Pilots select a suit based on their body size, and it is custom fitted with adjustable panels in the torso, arms and legs. Each pilot has two suits, and each one costs about $125,000, officials said.
The suits are bulky. It takes three people to get the pilot suited up, checked out and strapped into the aircraft.
"Getting suited up requires a little flexibility, a little patience and a lot of faith," Major Bartholomew said. "Once I step out of the locker room, I basically let the technicians do all the work."
Pilots climb into the suit through an opening in the back. It takes about fifteen minutes to get the pilot dressed and run through the leak checks. At the aircraft, a technician straps the pilot into the ejection seat and makes all the connections to oxygen, cooling air and communications.
"The suit is not uncomfortable per se, but the U-2 pilots typically fly missions in excess of nine hours, and anything you are sitting in for that long can become uncomfortable," Sergeant Hawley said. "The pilots are fatigued, tired, and sweaty when they return, and they just want to get out of the aircraft and stretch out after being cramped in it for hours."
"When the pilots come down and they say that everything worked fine, that's almost like a thanks to me," Sergeant Elmore said. "At the debrief we ask if the equipment was OK. If they give us thumbs up, that's good enough for me."
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