Each of the two blades was attached to the rotor hub by means of a metal sheet bent so as to form an angle. Movements of this 'blade attaching angle', which could (as it were) be twisted, controlled pitch changes. There was thus no need for bearings, hinges, dampers, etc.
In addition, as stated above, lateral and longitudinal control were effected by changing the centre of gravity. By using a stick attached at its lower end to a swivel fitting to the fuselage structure, the pilot could displace his cabin, which was mounted on links, forwards, backwards or to either side.
This helicopter made its maiden flight on 20th September 1947.
P.Lambermont "Helicopters and Autogyros of the World", 1958
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Technical data for Seibel S-3
Engine: 1 x 65hp Franklin , rotor diameter: 7.62m, loaded weight: 365kg, empty weight: 245kg, cruising speed: 112km/h, inclined climb: 275m/min, absolute ceiling: 3660m