Lateral Flight-Path Control by Rudder Steering under Holding Roll Angle

Most airplanes use their ailerons to compensate the lateral displacement deviation from a reference flight-path. This study proposes a method of lateral flight-path control due to the rudder steering under constraint of automatic roll angle hold. This control method is estimated analytically to produce quicker lateral displacement response than the control due to aileron. Then, experiments using a flight simulator are carried out to evaluate the control characteristics on the task of holding the flight path. The pilot’s evaluation results show that, the rudder steering method gives better flying qualities than aileron steering method. Furthermore, as the more practical control measures, the mixture type of method is worked out, which is transferred from aileron steering to rudder steering depending on the lateral displacement deviation from a reference flight-path.