https://l450v.alamy.com/450v/P8MC8F/senior-airman-tim-johnson-and-senior-airman-hunter-mitchell-aerospace-propulsion-specialist-179th-airlift-wing-maintenance-group-evaluates-an-engine-of-the-c-130h-hercules-while-it-is-running-june-26-2018-at-the-179th-airlift-wing-mansfield-ohio-june-26-2018-the-diagnostic-test-requires-the-engine-to-be-running-for-the-airman-to-properly-identify-the-cause-of-this-particular-issue-and-is-also-known-by-aircraft-mechanics-as-man-on-the-stand-us-air-national-guard-photo-by-capt-paul-stennettreleased-P8MC8F.jpg