Secretary of Defense Chuck Hagel shakes hands with Ricki Selva, the wife of U.S. Air Force Gen. Paul J. Selva, during a change of command ceremony May 5, 2014, at Scott Air Force Base, Ill. Selva assumed command of U.S. Transportation Command from Gen. William M. Fraser III, who retired from the Air Force after 40 years of service. (DoD photo by Mass Communication Specialist 1st Class Daniel Hinton, U.S. Navy/Released)