170829-F-YH293-0004
U.S. Air Force Lt. Col. Christopher Hawn, 489th Bomb Group commander, tests his oxygen mask at RAF Fairford, U.K., Aug. 29, 2017. Hawn was preparing to go on a mission for Exercise Ample Strike, which is a Czech Republic-led exercise offering advanced air/land integration training to forward air controllers, joint terminal attack controllers and close air support aircrews. (U.S. Air Force photo by Master Sgt. Ted Daigle)