Col. Joe Lindsey, 319th Mission Support Group commander, hands the 319th Operations Support Squadron guidon to Lt. Col. Jonathan Castellanos in a change-of-command ceremony, June 7, 2013, at Grand Forks Air Force Base, N.D. Castellanos formerly served as the 319th Air Base Wing chief of safety, and will now lead the 319th OSS, which is responsible for air traffic control, radar control, base operations, life support, tower operations and airfield management. The change-of-command ceremony is a time-honored military tradition where the outgoing commander relinquishes the unit flag to the incoming commander, symbolizing continuity of command. (U.S. Air Force photo/Staff Sgt. Susan L. Davis)