Demoiselle
Role	Experimental aircraft
National origin	France
Designed by	Alberto Santos-Dumont
First flight	1908

The Santos-Dumont Demoiselle ("Damselfly") was an early aircraft built in France by Brazilian aviation pioneer Alberto Santos-Dumont. It was a light-weight monoplane with a wire-braced wing mounted atop an open-framework fuselage built around a reinforced bamboo boom. The pilot's seat was below the wing, and between the main wheels of the undercarriage. The rear end of the boom carried a tailwheel and a conventional empennage. As originally designed (as the Santos-Dumont No. 19) Santos-Dumont used a liquid-cooled Dutheil & Chalmers engine rated at 15 kW (20 hp) mounted on the leading edge of the wing. Later, the inventor repositioned the engine to a lower location, placing it in front of the pilot. The Demoiselle was controlled in flight by a tail unit that functioned both as elevator and rudder, which the pilot operated with a steering wheel.

The No. 19 was damaged beyond repair when crashed by Hélène Dutrieu in 1908. Santos-Dumont's next Demoiselle, the No. 20, featured an 18-kW (24-hp) Antoinette engine and some wing reinforcements. It also utilised wing warping for lateral control. Due to structural problems and continuing lack of power Santos-Dumont introduced additional modifications in the No. 21: a triangular and shortened fuselage made of bamboo; the engine was moved back to its original position, in front of the wing; and increased wingspan. The design of No. 22 was similar to No. 21. Santos-Dumont tested opposed-cylinder (he patented a solution for cooling this kind of engine) and water-cooled engines, with power settings ranging from 15–30 kW (20–40 hp) in the two variants. A feature of the water-cooled variant was the liquid-coolant pipeline which followed the wing lower side lofting to improve aerodynamics.

The Demoiselle could be constructed in only fifteen days. Possessing outstanding performance, easily covering 200 m of ground during the initial flights and flying at speeds of more than 100 km/h, the Demoiselle was the last aircraft built by Santos-Dumont. He performed flights with it in Paris, and made trips to nearby places. Flights were continued at various times through 1909, including the first cross-country flight with steps of about 8 km, from St. Cyr to Buc on 13 September 1909, returning the following day, and another on 17 September 1909 of 18 km in 16 min. The Demoiselle, fitted with a two-cylinder engine, became rather popular. The French World War I ace Roland Garros flew it at the Belmont Park, New York, in 1910. The June 1910 edition of the Popular Mechanics magazine published drawings of the Demoiselle and affirmed that "This machine is better than any other which has ever been built, for those who wish to reach results with the least possible expense and with a minimum of experimenting."^[1] American companies sold drawings and parts of Demoiselle for several years thereafter. Santos-Dumont was so enthusiastic about aviation that he released the drawings of Demoiselle for free, thinking that aviation would be the mainstream of a new prosperous era for mankind. Clément Bayard, an automotive maker, constructed several Demoiselles, which were sold for 50,000 francs.

An example of a No .21 with a Darracq engine is preserved in the Musée de l'Air et de l'Espace.

[edit] Variants

• No. 19
• No. 20
• No. 21
• No. 22

[edit] Specifications (No. 20)

Data from Aviafrance

General characteristics

• Crew: One pilot
• Length: 8.00 m (26 ft 3 in)
• Wingspan: 5.10 m (16 ft 10 in)
• Height: 2.40 m (7 ft 11 in)
• Wing area: 10.2 m² (110 ft²)
• Gross weight: 143 kg (314 lb)
• Powerplant: 1 × Darracq, 26 kW (35 hp)

Performance

• Maximum speed: 90 km/h (60 mph)

[edit] Notes

[edit] References

• "Santos-Dumont 20 'Demoiselle'". Aviafrance. http://www.aviafrance.com/9614.htm. Retrieved 2009-02-10. 
• Joerin, Arthur E.; A. Cross (June 1910). "How to Build the Famous 'Demoiselle'". Popular Mechanics: 778–779. http://www.geocities.com/CapeCanaveral/Hangar/9260/demoisel.htm. Retrieved 2009-02-09. 
• Taylor, Michael J. H. (1989). Jane's Encyclopedia of Aviation. London: Studio Editions. 

v • d • e Aircraft built by Alberto Santos-Dumont No.1 • No.2 • No.3 • No.4 • No.5 • No.6 • No.7 • No.8 • No.9 • No.10 • No.11 • No.12 • No.13 • No.14/No.14bis • No.15 • No.16 • No.17 • No.18 • No.19 • No.20 • No.21 • No.22 •

v • d • e Lists relating to aviation General Timeline of aviation · Aircraft (manufacturers) · Aircraft engines (manufacturers) · Rotorcraft (manufacturers) · Airports · Airlines · Civil authorities · Museums Military Air forces · Aircraft weapons · Missiles · Unmanned aerial vehicles (UAVs) · Experimental aircraft Accidents/incidents General · Military · Commercial (airliners) · Deaths Records Airspeed · Distance · Altitude · Endurance · Most-produced aircraft