Secretary of Defense Chuck Hagel, left, passes the U.S. Transportation Command colors to Air Force Gen. Paul J. Selva during a change of command ceremony May 5, 2014, at Scott Air Force Base, Ill. Selva assumed command from Gen. William M. Fraser III, right, 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)