Yves Chasle, who is a stress engineer with Sud, has designed and built the YC-12 Tourbillon single-seat light aircraft, which made its first flight on 9th October 1965. Following flight trials, certain modifications were incorporated in the tail-plane and the height of the vertical surfaces increased slightly. The fuselage is of plywood-covered wood construction and the wings are of similar fabrication with girder-type ribs. All-wood ailerons are fitted as well as three-position slotted flaps. The tail unit has swept vertical surfaces and the prototype had an automatic anti-tab on the horizontal surfaces which was controllable in flight, but production aircraft have a fixed tailplane with conventional elevators. The undercarriage is of the non-retractable tailwheel type, with a steerable tailwheel linked with the rudder.
The prototype Tourbillon had a 65-h.p. Rolls-Royce Continental A65 four-cylinder engine driving a two-blade propeller, and production aircraft are available with 95- h.p. Continental (YC-122) and 105-h.p. Potez 4E (YC-123) engines as well as the original 65-h.p. engine in the YC-121.
The production version of the aircraft varies slightly in overall dimensions from the prototype and these are quoted here together with data relevant to the YC-121 Tourbillon. Span is 22 ft., length 19 ft. 6 in., empty weight 628 lb. and maximum take-off weight 952 lb. Maximum speed is 146 m.p.h. and cruising speed 127 m.p.h. Rate of climb at sea-level is 905 ft./min., take-off run 855 ft. and range 500 miles. Estimated top speeds of the YC-122 and YC-123 versions are 168 m.p.h. and 176 m.p.h. respectively.
Type YC-12 Tourbillon
Engines 1 x 65 h.p. Continental (YC-121) or 95 h.p. Continental (YC-122) or 105 h.p. Potez 4F (YC-123)
Span 22 ft 0 in.
Overall Length 19 ft. 6 in.
Max. Take-off Weight 952 lb.
Take-off run 855 ft.
Range 500 miles