Col. Shaun McGrath (left), 20th Operations Group commander, presents Lt. Col. Jason Plourde, 79th Fighter Squadron (outgoing) commander with the Meritorious Service Medal for his actions in the line of duty during a change of command ceremony, Shaw Air Force Base, S.C., April 12, 2013. A change of command is a military tradition that represents the transfer of responsibilities from the presiding official to a qualified selected official. (U.S. Air Force photo by Airman 1st Class Daniel Blackwell/released)