Col. Joseph Sheffield, the 28th Bomb Wing commander, left, Col. Nathan Mitchell, the 28th Maintenance Group incoming commander, middle, and Col. Chad Heyen, the 28th Maintenance Group outgoing commander, right, stand for the playing of the Air Force song during a change of command ceremony on Ellsworth Air Force Base, S.D., August 4, 2021. The 28th Maintenance Group is responsible for fixing and providing maintenance on 21 B-1B Lancers,as well as associated support equipment. (U.S. Air Force photo by Airman 1st Class Jonah Fronk)