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

  • Published
  • By Airman 1st Class Bobby Cummings
  • 9th Reconnaissance Wing Public Affair
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."