A Study of Maximum Range Flight of Gliders.

By using of the optimal control theory, the optimal controls of the lift coefficient and the related flight paths of gliders are obtained to find the maximum flight range for given initial and final conditions. The results show that without ground effect the steady gliding flight at the maximum lift-to-drag ratio occupies a greater part of the flight path, but with the ground effect, the unsteady horizontal flight at the minimum allowable height takes the place of the steady gliding flight.