A Mathematical Model for Helicopter Flight Path Control

This article presents a new mathematical model for helicopter flight path control with the features of flexibility and mathematical simplicity. The model presents a control system for achieving flight along a selectable flight path angle in the accelerating or decelerating flight of a VTOL aircraft such as a helicopter, particularly in take off or landing maneuvers covering the range between the hovering mode and safe airspeed. The selectable flight path angle guidance is provided by cooperative use of a novel flight director system and the thrust and pitch attitude controls of the aircraft; thrust control being employed to maintain a selected flight path angle, while pitch attitude is used to control accelerating or decelerating of the craft to a constant speed which is a function of the selected flight path angle.