U.S. Air Force Col. Helen Brasher, 20th Maintenance Group commander, passes the unit guide-on to Maj. Michael Fields, incoming commander for the 20th Aircraft Maintenance Squadron, Shaw Air Force Base, S.C., June 17, 2013. Changes of command are military tradition that represents the transfer of responsibilities from the presiding officials to the upcoming official. (U.S. Air Force photo by Airman 1st Class Ashley L. Gardner/Released)