Col. Paul Gates, 434th Air Refueling Wing vice commander, left, administers the oath of office to Col. Brian Hollis, 434th Operational Support Squadron commander, during Hollis’ promotion ceremony at Grissom Air Reserve Base, Ind., April 7, 2018. Hollis is among one percent of Air Force officers who make the rank of colonel during their military career. (U.S. Air Force photo/Tech. Sgt. Benjamin Mota)