Staff Sgt. David Morales, 51st Operations Support Squadron airfield management operations supervisor, monitors the flightline while an A-10 Thunderbolt II assigned to the 25th Fighter Squadron lands Nov. 3, 2015, at Osan Air Base, Republic of Korea. Morales is responsible for ensuring the flightline is operational for every aircraft participating in the peninsula-wide readiness exercise Vigilant Ace 16. Vigilant Ace 16 is a large-scale exercise designed to enhance the interoperability of the U.S. and Republic of Korea Air Forces. (U.S. Air Force photo/Staff Sgt. Benjamin Sutton)