Air Force Senior Airman Tim Johnson evaluates the engine of a C-130H Hercules while it is running at the 179th Airlift Wing in Mansfield, Ohio, June 26, 2018. Johnson is an aerospace propulsion specialist assigned to the Ohio Air National Guard’s 179th Airlift Wing Maintenance Group. The diagnostic test requires the engine to be running for the airman to identify the cause of the issue. Ohio Air National Guard photo by Capt. Paul Stennett