Minimum Time Turn of a Helicopter

Using a point mass approximation, two and three dimensional minimum time turn problems of a helicopter are formulated as the nonlinear optimal control problems. Optimum solutions are obtained numerically by SCGRA and MQA. The rotor is modeled as an ideal aerodynamic force generator which provide the thrust and the lift as well as control forces of the vehicle without any inertia effect. It is clarified the minimum time turn performances of the helicopter are consisted with bang-bang controls of the angle of attack of the rotor and the engine power and largely dependent on its autorotation capability. It is also revealed that for a rotary wing aircraft such as a helicopter, proper inclusions of the rotor induced power are essential for its maneuverability optimization.