U.S. Air Force Lt. Col. Joseph D. Wall, the new 79th Air Refueling Squadron commander, speaks during a change of command ceremony at Travis Air Force Base, Calif., Jan. 7, 2017. Wall promised transparency, competence and commitment to excel by leveraging the combined experience and talents of the Citizen Airmen under his charge. (U.S. Air Force photo by Senior Airman Chris Massey)