Staff Sgt. Nathan Rookstool, 8th AMXS dedicated crew chief, watches as an engine run test is underway at Kunsan Air Base, Republic of Korea, Dec. 15. 2011. Rookstool was one of three Airmen who received training on the proper way to perform an engine run test this past week from the 8th Maintenance Operations Squadron maintenance training flight. (U.S. Air Force photo/Senior Airman Benjamin Stratton/Released)