Viper in the visor Published Jan. 29, 2015 931st Air Refueling Group MCCONNEL AIR FORCE BASE, Kan. -- Tech. Sgt. John Bui, a refueling boom operator assigned to the 18th Air Refueling Squadron, 931st Air Refueling Group, McConnell Air Force Base, Kan., peers through his helmet visor while refueling an F-16 Fighting Falcon assigned to the Colorado Air National Guard's 140th Fighter Wing, Jan. 27, 2015. Reservists from the 931st Air Refueling Group operate and maintain the KC-135 Stratotanker in support of Air Mobility Command's worldwide air refueling mission, meeting the air refueling needs of all U.S. Air Force, Navy, Marine, and selected allied nations' aircraft. (U.S. Air Force photo by Senior Airman Sierra Dopfel.)