The control apparatus acquires an ideal velocity characteristic of a control surface, and the temperature of pressure oil of the actuator to be tested and the operating speed of the control surface when the actuator is attached to the control surface. The control apparatus corrects the ideal velocity characteristic of the control surface by using the pressure oil temperature and the control surface operating speed. The control apparatus sets an upper limit and a lower limit by using a predicted value for a fluctuation range for a fluctuation factor that causes a fluctuation of the control surface operating speed, with reference to the corrected ideal velocity characteristic, measures the pressure oil temperature and the operating speed by actuating the control surface, with the actuator to be tested placed in a damping mode, and determines whether the measured value falls within the range between the upper limit and the lower limit.