The 1909 Demoiselle, designed by Brazilian aviation pioneer Alberto Santos-Dumont, is one of the earliest successful light aircraft. Known for its delicate and elegant appearance, the Demoiselle (“dragonfly” in French) was one of the first airplanes intended for sport and personal flying. It was a true ultralight for its time, constructed from bamboo and wire with fabric-covered wings, and it became an icon of early aviation innovation.
The Demoiselle was powered by small lightweight engines, typically between 20 to 35 horsepower, and could reach speeds of up to 37 mph. Remarkably simple in design, it featured a minimal frame, a forward-mounted engine, and tail surfaces for control. Its accessibility and ease of construction even inspired published plans, allowing amateur builders to replicate the aircraft.
Although fragile by modern standards, the Demoiselle represented an important step toward practical, recreational aviation and is celebrated as one of the world’s first truly “personal” airplanes.
DEMOISELLE NOTES
One of the earliest ultralight aircraft, the Demoiselle embodied the dream of accessible, personal flight and remains a symbol of aviation’s pioneering spirit.
PRODUCTION
• Number Built: Fewer than 50 (including amateur builds)
• Year Produced: 1909–1910
• Designer: Alberto Santos-Dumont
MEASUREMENTS
• Length: 26 ft. 3 in.
• Wingspan: 18 ft. 0 in.
• Empty Weight: 242 lbs.
• Loaded Weight: 350 lbs.
• Engine: Darracq or Clement-Bayard / 20–35 hp
PERFORMANCE
• Cruising Speed: 31 mph
• Max Speed: 37 mph
• Range: Approx. 36 miles
• Ceiling: Low altitude (visual flight)
• Rate of Climb: Approx. 200 ft./min.
