Airmen assigned to the 28th Aircraft Maintenance Squadron perform pre-flight checks on a B-1 bomber assigned to the 34th Bomb Squadron at Ellsworth Air Force Base, S.D., July 24, 2012. The 28th AMXS is the largest squadron in the 28th Bomb Wing with more than 700 Airmen, supporting 28 combat coded B-1 bombers. (U.S. Air Force photo by Airman 1st Class Zachary Hada/Released)