U.S. service members salute during a rendition of the national anthem at the 633rd Air Base Wing change of command ceremony Joint Base Langley-Eustis, Va., June 22, 2017. U.S. Air Force Col. Sean Tyler assumed command of the unit, which provides installation support to more than 18,000 Airmen, Soldiers and civilians across two major command headquarters, 13 operational wings and Army brigades, and more than 20 associate units. (U.S. Air Force photo/Staff Sgt. R. Alex Durbin)