The SO.1100 Ariel (I) first flew tethered on 14 May 1947. A Mathis piston engine drove a compressor feeding air to burners at the rotor tips. In its original form it also had a pusher propeller and a stub wing with endplates, in order to fly as an autogyro in cruise. Rebuilt as seen as a pure helicopter with a tailboom it first flew on 7 March 1949. Through the SO.1110 Ariel II and SO.1120 Ariel III, development eventually led to the SO.1221 Djinn. Photo from: Nationaal Archief (Netherlands)