U.S. Air Force Staff Sgt. Michael Hoffman wipes away residual oil from an HC-130 Combat King II cargo aircraft during a Vigilant Ace 16 aeromedical evacuation training mission on Osan Air Base, South Korea, Nov. 5, 2015. Hoffman is a crew chief assigned to the Alaska National Guard’s 176th Aircraft Maintenance Squadron. U.S. Air Force photo by Staff Sgt. Benjamin Sutton