A U.S. Air Force crew chief from the 125th Fighter Wing, waits for an F-15 Eagle to taxi during the Trident Warrior exercise at Langley Air Force Base, Va., July 18, 2013. During testing, the pilots were divided into two teams titled “Blue Force” and “Red Force,” in simulated aerial combat. (U.S. Air Force photo by Staff Sgt. John D. Strong II / Released)