John Columbia, a U.S. Air Force loadmaster with the 15th Special Operations Squadron, inspects his oxygen mask during a flying mission for Emerald Warrior 2011 at Hurlburt Field, Fla., March 1, 2011. Emerald Warrior is an annual two-week joint/combined tactical exercise sponsored by U.S. Special Operations Command designed to leverage lessons learned from operations Iraqi and Enduring Freedom to provide trained and ready forces to combatant commanders.