Abstract: A redundant engine starting system is disclosed that includes at least first and second sub-starters that rotate corresponding sub-starter output shafts affixed by a joining gear to rotate an engine starter shaft to start the engine. Each sub-starter includes a speed sensor for detecting rotational speed of the sub-starter, and a control valve to control rotational speed of the sub-starter. A system control intelligence interprets sensed rotational speeds of the sub-starters and commands the control valves, so that the control valve of an operative sub-starter is commanded to allow increased rotational speed of the sub-starter and therefore its corresponding output shaft whenever the system control intelligence interprets the sensed rotational speed of an inoperative sub-starter.