Lt. Col. Barry Hutchinson, 28th Bomb Wing chief of plans, records control readings during a hot pit refuel of a B-1 bomber at Ellsworth Air Force Base, S.D., Feb. 12, 2013. Hot pit refueling, usually performed in a combat environment, is a carefully controlled process during which two engines continue running, which reduces maintenance turn time for the aircraft. (U.S. Air Force photo by Airman 1st Class Alystria Maurer/Released)