U.S. Air Force Gen. Paul J. Selva walks between Navy sideboys as he arrives for a change of command and retirement ceremony for Gen. William M. Fraser III, background, May 5, 2014, at Scott Air Force Base, Ill. Selva assumed command of U.S. Transportation Command from Fraser, 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)