His YC-100 Hirondelle is a largely wooden framed and fabric covered single-seat sports aircraft of conventional pusher layout.
The fuselage of the Hirondelle is a slender, rectangular cross-sectioned beam with the pilot's seat upon it ahead of the wing leading edge.
Behind the pilot a central structure supports the wing just above head level; on its trailing edge, one of several types of small piston engine, with power outputs typically around 20 kW (27 hp), drives a pusher propeller.
[1] Its first flight was on 1 May 1985, powered by a 18 kW (24 hp) König SC 430 engine, a 430 cc (26.2 cu in), air-cooled, three-cylinder radial.
The second prototype, built in Brazil, had a 16 kW (22 hp) JPX PUL 425/503 engine, a 212 cc (12.9 cu in) air-cooled flat-twin two stroke.