U.S. Air Force Tech. Sgts. Tim Chase, foreground, and Danny Bogan prepare to fly on an Afghan air force Mi-17 helicopter on Hamid Karzai International Airport, Kabul, Afghanistan, Dec. 7, 2015. Chase is a flight engineer and Bogan is an aerial gunner assigned to the Train, Advise, Assist Command-Air. U.S. Air Force photo by Staff Sgt. Corey Hook