A B-1 bomber thunders down the flightline during the start of a training mission at Ellsworth Air Force Base, S.D., July 24, 2012. B-1 aircrews consisting of two pilots and two weapon systems officers complete training sorties to meet flight certifications and to have their skills to ensure they are ready for any combat situation anywhere around the world. (U.S. Air Force photo by Airman 1st Class Zachary Hada/Released)