US Patent 8256705 Torque production vehicle and method

A torque production vehicle includes a plenum body having a wall with a central port and a radial port formed within the wall, an impeller disposed within the plenum body to move air through the central port, an engine coupled to the impeller to rotate the impeller about an axis, at least one arm coupled to the plenum body, and a plurality of foils disposed in the radial port to direct air about the plenum body to provide a torque force about the plenum body.