U.S. Air Force Staff Sgt. Jacob Durham, 307th Aircraft Maintenance Squadron crew chief, works on the hydraulic system of a B-52 Stratofortress at RAF Fairford, England, Sept. 8, 2019. The process is part of routine maintenance conducted between sorties. The aircraft was being prepared for a mission to support both Exercise Ample Strike 19 and Exercise Cobra Warrior. Both exercises provide critical training, improve interoperability, and enhance cooperation between the U.S. military and its NATO partners and allies. (U.S. Air Force photo by Master Sgt. Ted Daigle)