PURPOSE: To attain a flight in the atmosphere and outside the atmosphere without using a propellant by utilizing the moment force against space (reaction force from the mass field) generated when the rotation axis of a rotor or the calculational rotation axis is uniformly displaced against the mass center.

CONSTITUTION: A rotor 1 having the actual rotation axis 2 is rotated, the rotation axis 2 is properly displaced by a moving device 3 symmetrically with the symmetrical axis 4, then the moment force against space (reaction force from the mass field) is generated. The moment force against space is utilized to generate thrust via the combination of the direction of the rotating mass field and the displacement direction, and an airframe is flown. The airframe can be flown in the atmosphere or outside the atmosphere without using a propellant.