Stable flight can be achieved without the need for a complicated throttle operation by a pilot even when part or all of control surfaces malfunction. A computer (15) calculates a thrust control signal for controlling engine thrust and a deflection angle control signal for controlling control surfaces based on state information regarding an airframe and an operation command signal from an operation end. An engine control unit (17) drives an engine based on the thrust control signal. An actuator (16) moves the control surfaces based on the deflection angle control signal.