Controllability Limit of a Human Pilot

The limit of a human pilot's capability in controlling an unstable second-order system, hereafter called an element, is theoretically analyzed; the transfer function of the human pilot is assumed, and the stability boundary of the closed system consisting of the human pilot and the controlled element is analyzed. The boundary thus obtained is considered to suggest the theoretical controllability limit of the human pilot. In connection with the theoretical analysis, fixed-base flight simulator tests are conducted; the analogous controlled element is set in the simulator, and the controllability limit is investigated by an experienced pilot. The physical interpretation of the experimental data \vith respect to the theoretical results shows good insight into the controllability limit of the human pilot.