Upgrades target decompression sickness in U-2 pilots

by Airman 1st Class Bobby Cummings
9th Reconnaissance Wing Public Affairs

8/15/2013 - BEALE AIR FORCE BASE, Calif.  -- 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 was one of the chief concerns for U-2 "Dragon Lady" pilots flying within 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.

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 which 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 the number of available aircraft for missions.

"It was a huge team effort from the maintenance squadrons here and Lockheed Martin to maintain combat mission readiness for our pilots," said Col. Chad Clifton, 9th Maintenance Group commander. "Before CARE started, we were conducting 141 sorties per month. Once CARE commenced, we were still able to conduct 140 sorties per month, and we are very proud of that."

Thanks to the CARE modifications, the risk of DCS is decreased.

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