181010-F-WZ808-0053
U.S. Air Force Staff Sgt. Juan Upegui, 351st Air Refueling Wing boom operator, conducts pre-flight checks prior to an air refueling mission for a large forces exercise, at RAF Mildenhall, England, Oct. 10, 2018. RAF Lakenheath hosted the exercise, which took place in the U.S. European Command area of operations. (U.S. Air Force photo by Staff Sgt. Christine Groening)