U.S. Air Force Staff Sgt. Christopher Hudson, 7th Component Maintenance Squadron test cell craftsman, completes performance adjustments on a B-1B Lancer/F101 engine after an idle engine check Dec. 22, 2015, at Dyess Air Force Base, Texas. Before testing the engine at a high RPM rate, test cell Airmen first run the engine at idle to check performance at lower settings. After making performance adjustments at idle, engine run personnel perform another idle engine check, and test the engine at its peak RPM levels. (U.S. Air Force photo by 2nd Lt. Lauren Linscott/Released)