|Sud-Ouest SO.1100 "Ariel"|
Early company interest in the development of rotary wing aircraft led to design and construction of the Sud-Ouest S.O.1100 Ariel I, an all-metal helicopter with an enclosed cabin for two. The company had sought simplicity by the use of a single three-blade torqueless rotor, driven by tip jets. Thus its powerplant comprised a 164kW Mathis G8 engine driving a Turbomeca compressor, providing low-pressure air which was fed through the hollow rotor blades to the combustion chambers of the tip jets, where the air was mixed with fuel and ignited electrically. In its original form as the Ariel I, first flown in 1947, the helicopter had a stubby tail boom incorporating twin vertical surfaces.
The improved S.O.1110 Ariel II, flown on 23 March 1949, was of generally similar configuration but had revised twin tail surfaces. However, the two-unit powerplant of these first two prototypes was heavy, and in the improved S.O.1120 Ariel III it was replaced by a much lighter weight 205kW Turbomeca Arrius turbine-compressor unit, the weight saving making it possible to accommodate an additional passenger. The Ariel III also differed from its predecessor by having a tail unit that was basically a single fin and rudder, but supplemented in its steering capability by the efflux from the turbine. This was ducted to the tail and could be discharged on either side under the control of deflector vanes coupled to the conventional rudder. The Ariel was not to be built as a production helicopter, but the data gained from this powered rotor system was to be of value in development of the S.O.1220 Djinn.
D.Donald "The Complete Encyclopedia of World Aircraft", 1997
Two-seat helicopter with rotor-tip jet propulsors powered by Compressor from a 220hp Mathis G8 engine. Pod fuselage with tricycle u/c and shrouded rear prop. Later modified with a tail boom. One Prot. F-WFKM FF 14 May 1947.
R.Simpson "Airlife's Helicopter and Rotorcraft", 1998
This two-place jet helicopter, developed by Societe Nationale de Constructions Aeronautiques du Sud-Ouest, of France, and flown in 1947, was the predecessor of the SO.1110 "Ariel II" and SO.1120 "Ariel III" helicopters, all powered by turbo-jets which supply compressed air to tip burners.