U.S. service members stand in formation during the 633rd Air Base Wing change of command ceremony at Joint Base Langley-Eustis, Va., June 22, 2017. The incoming commander, U.S. Air Force Col. Sean Tyler, previously served at Langley in a variety of positions throughout his career, including as a flight commander, executive officer and deputy group commander. (U.S. Air Force photo/Staff Sgt. R. Alex Durbin)