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BRAIN LESIONS IN SPY PLANE PILOTS? - Upgrades in U-2 target decompression sickness

A U-2 "Dragon Lady" takes off from the Osan Air Base, South Korea, flightline Oct. 21, 2009, during the base Air Power Day air show. (U.S. Air Force photo/Staff Sgt. Brian Ferguson)

An U-2 Dragon Lady takes off from Osan Air Base, South Korea. The spy plane flies at altitudes above 70,000 feet, which poses unique risks to its pilots. (U.S. Air Force photo/Staff Sgt. Brian Ferguson)

C.J. Gaecke, a Lockheed Martin structure mechanic, explains Cockpit Altitude Reduction Effort modifications made to a U-2 airframe on June 25, 2013 at Beale Air Force Base, Calif. This aircraft was the last of 22 to receive such modifications at Beale. The upgrades virtually eliminate the risk of decompression sickness and hypoxia. (U.S. Air Force photo by Airman 1st Class Bobby Cummings/Released)

C.J. Gaecke a Lockheed Martin structure mechanic, explains Cockpit Altitude Reduction Effort modifications made to an U-2 airframe on June 25 at Beale AFB, Calif. This aircraft was the last of 22 to receive such modifications at Beale. The upgrades seek to eliminate the risk of decompression sickness and hypoxia. (U.S. Air Force photo by Airman 1st Class Bobby Cummings/Released)

Staff Sgt. Nikolina Kreager, a life support specialist with the 99th Expeditionary Reconnaissance Squadron at an air base in Southwest Asia, ensures a U-2 Dragon Lady pilot is set for the day's mission by checking the flight suit to make sure it can pressurize properly at high altitudes.  (U.S. Air Force photo/Senior Airman Levi Riendeau)

Staff Sgt. Nikolina Kreager a life support specialist with the 99th Expeditionary Reconnaissance Squadron at an air base in Southwest Asia, ensures an U-2 Dragon Lady pilot is set for the day’s mission by checking the flight suit to ensure it can pressurize properly at high altitudes. (U.S. Air Force photo/Senior Airman Levi Riendeau)

BEALE AIR FORCE BASE, Calif. (ACCNS) -- There are a multitude of potential risks that exist while flying at more than 70,000 feet, and many of them have substantial consequences. Decompression sickness and brain
lesions were two of the chief concerns for U-2 "Dragon Lady" pilots flying within an arm's reach of the stars.

Commonly referred to as DCS, decompression sickness generally begins with the formation of nitrogen bubbles in blood or body tissues, and is caused by inadequate elimination of this dissolved gas after exposure to extreme pressures.

Between May 2011 and October 2012, the Air Force conducted MRIs on 105 U-2 pilots, ranging in age from 26 to 50, said Dr. Stephen McGuire, a neurologist and retired Air Force colonel who led the study. Of those pilots, 75 percent had more brain lesions than they should for their age and current health, according to a report in the Air Force Times. These are the same type of lesions caused by repeated head trauma, the report said.

Thanks to an Air Force-wide effort, Cabin Altitude Reduction Effort (CARE) modifications have been implemented into 27 U-2 airframes, reducing the altitude equivalent within the cockpit from 29,500 feet, roughly the height of Mt. Everest, to 15,000 feet, while at altitude. The CARE modification reinforces the airframe structure, replaces valves, changes the bleed air system logic, and alters cockpit controls.

DCS was a major concern U-2 pilots faced prior to the CARE modification, according to Lt. Col. Brian Musselman, 9th Physiological Support Squadron commander.

The total cost of the CARE program for the 22 aircraft that received modifications here was $8.7 million.

"It's heartening to know even in these financially constrained times money is being utilized to ensure the safety of our pilots," said Lt. Col. Colby Kuhns, 1st Reconnaissance Squadron commander. "Since the CARE modifications have occurred, there have been no reported DCS incidents."

U-2 pilots reported an increased number and severity of neurological DCS incidents during 2002-2009 compared to earlier periods. The CARE modification seeks to eliminate the risk of DCS.

"To eliminate the risk of DCS for U-2 pilots is phenomenal," Musselman said. "It's an operational solution for a human performance issue."

Lockheed Martin maintenance crews worked 10-hour shifts for six days a week from September 2012 to June 2013. To complete the project, an additional five airframes received CARE modifications at Program Depot Maintenance in Palmdale, Calif.

Each aircraft modification took 33 days to complete. At any given time, four aircraft were simultaneously receiving modifications, which minimized aircraft available for missions.

"Maintaining the health of our pilots is paramount," said Col. Chad Clifton, 9th Maintenance Group commander. "An unhealthy pilot force would have substantial negative effects on mission capability. The CARE modifications are a game-changer for the U-2 community."