PURPOSE: To improve control performance by applying a corrective pitch and a cyclic pitch to rotor blades, generating moment by means of pitch changes of the blades, and controlling behaviors via the cooperation with the moment from air streams.

CONSTITUTION: When both the corrective pitch and cyclic pitch of counter- rotating rotors 16, 18 are controlled, nose-up moment MS as shown in the figure is generated in the lift or moment generating characteristic of a fuselage 12. When the air inflow quantity becomes maximum at the O-position or rear position of the duct 54 of the fuselage 12 by cyclic pitch control, nose-down moment MR countering the nose-up moment MS is generated, and it cooperates with the nose-down moment MR generated by the rotor 16. A relation shown in the figure exists among the cyclic pitch angle, nose-up moment MS and nose-down moment MR, and the behaviors of a flight vehicle are controlled by the control of the cyclic pitch angle.