A U.S. Air Force HH-60 Pave Hawk drops off troops during a search and rescue demonstration at the Seoul International Aerospace and Defense Exhibition (ADEX) 2017 at Seoul Air Base, Republic of Korea, Oct. 21, 2017. The Seoul ADEX is the largest, most comprehensive event of its kind in Northeast Asia, attracting aviation and aerospace professionals, key defense personnel, aviation enthusiasts and the general public alike. (U.S. Air Force photo by Staff Sgt. Alex Fox Echols III)