Tale of the Damselfly
It was the world's first flight of a powered, heavier-than-air flying machine, or so everybody thought at the time. The date was November 12, 1906, and the setting was not the bleak sand dunes of Kitty Hawk, North Carolina, but the manicured gardens of the Bagatelle Park in the eastern suburbs of Paris. The elegantly attired aeronaut, Alberto Santos-Dumont, stood upright in his #14bis, an ungainly, tail-first contraption inspired by the box kite that he managed to coax into the air four times. His best flight was a powered hop lasting 21 seconds and covering 722 feet. The diminutive, daring Brazilian pioneer was hailed as the undisputed conqueror of the air.
Santos's reign lasted barely 20 months. In August 1908, Wilbur Wright arrived in France and unveiled the hitherto secret Wright airplane, which he and Orville had kept under wraps in the hopes of securing a lucrative military contract. Wilbur instantly dazzled the French public with his accomplished flying skills and established beyond doubt the credibility of the brothers' claim that they had first flown in 1903. Wilbur's triumph eclipsed Santos's reputation overnight. Over the next two decades, the Brazilian began a gradual descent into obscurity, illness, depression, and, finally, suicide, but not before he had perfected his most enduring legacy—the Demoiselle.
The Damselfly is born
The Demoiselle grew out of the obvious shortcomings of the #14bis. The latter's flights in 1906 had all been little more than uncontrolled jumps, so Santos set out to design a more compact and practical flying machine. After a few more failures, he finally hit upon a simplified monoplane layout in November 1907, nine months before Wilbur Wright's arrival in Paris. He called it Demoiselle—the French word for damselfly (mistranslated in many sources as dragonfly) as well as for a young girl.
The design was the heavier-than-air equivalent of Santos's celebrated tiny "runabout" airship, the #9 Baladeuse, which he used to steer along the Parisian boulevards and moor outside Maxim's for lunch. Although he couldn't land the Demoiselle in the streets, it was a simplified, scaled-down personal machine for everyday use. The Demoiselle was also the world's first sport plane, and it foreshadowed the classic layout of today's ultralights, which bring the dream of flight within reach of aspiring amateurs and homebuilders.
Santos applied his usual highly original and idiosyncratic touches to the design, and the plane had its share of teething troubles. In its first incarnation as the #19, the Demoiselle's fuselage consisted merely of a single bamboo pole. The engine was perched precariously at one end of the pole and a cruciform tail at the other, connected by a universal joint. The rest of the framework was mostly bamboo, covered in yellow Japanese silk. The pilot sat on a strap between the landing wheels. To improve the #19's stability, Santos enlarged the wings and installed a new 24 hp Antoinette engine in a highly vulnerable position—right between the pilot's legs! But this version, too, proved unsatisfactory.
A new, improved Demoiselle
Following Wilbur Wright's triumphant flights, Santos embarked on a more thorough redesign, the #20. He replaced the single pole with a more secure triangular bamboo frame and mounted a 30 hp twin engine of his own design between the wings. This version proved sufficiently airworthy for Santos to venture out on cross-country flights. On September 13, 1909, on a bet from a fellow pilot, he flew the five miles between St. Cyr and Buc, two small airfields west of Paris, in just five minutes at the unheard-of speed of 55.8 mph. As with many of his airship flights, engine problems would frequently lead to unplanned landings on the grounds of wealthy chateau owners around Paris, where he would make the most of the unexpected social opportunities.
During 1909, the automobile firm of Clément-Bayard became interested in mass-producing the Demoiselle. The company substituted tubular steel for the plane's frail bamboo fuselage and tail structures while retaining wooden wings. The firm set the price for the Demoiselle at some 20,000 francs cheaper than any other airplane. Since Santos believed fervently in bringing flight to the masses, he didn't patent the design and it was widely copied. In the U.S., Popular Mechanics magazine featured detailed Demoiselle drawings in its issues for June and July 1910, provoking a rash of homebuilt imitations in garages and workshops. The magazine prefaced its drawings with the comment, "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."
Whenever a tiny ultralight takes off today, the ghost of the Demoiselle flies behind it.
Despite its favorable press, the Demoiselle was a handful. Highly unstable, underpowered, and with insufficient wing surface area, it required courageous and experienced pilots. The Demoiselle's unusual control systems were part of the problem. They included a special flight jacket worn by the pilot with wires attached to it to warp the wings. (The practice of using flexible wing-tips rather than ailerons to control roll was much in vogue at the time, but attaching the control wires to an article of clothing was certainly novel!) There were separate hand controls for pitch and yaw, a foot-powered engine throttle, and steel-reinforced gloves for grasping and steering the wheels on landing. (To hear these and other features described in detail, see Tour the Demoiselle).
A rare breed
No original airworthy Demoiselle survives today, but an opportunity for a fresh look at the design arose when a reproduction was built in 1964 for the movie Those Magnificent Men in Their Flying Machines. Rather than wrestling with heavy and brittle bamboo, the builders chose the more practical steel tube design of the production Demoiselles. They simplified the controls by adding ailerons in place of wing warping and connecting them, along with the tail surfaces, to a conventional joystick.
Tested at White Waltham airfield outside London, the replica at first remained stubbornly earthbound: "The Demoiselle ran up the ridges and down the other side with a glued-to-Earth feeling about it which was extremely discouraging," reported Air Commodore Allen Wheeler. Even enlarging the wings by an extra two feet didn't help. Then it dawned on the builders that the slender Santos weighed a mere 110 pounds. They recruited test pilot Joan Hughes, who weighed about the same, and she managed to get the replica airborne.
Only when the builders added a 50 hp engine did the Demoiselle come into its own and prove itself as one of the most practical of the many early airplanes reconstructed for the movie. Since the original had 20 hp less power, its performance must always have been marginal and dependent on both the skill and body weight of the pilot.
Whatever the Demoiselle's drawbacks in the air, its compact, affordable design and Santos's flamboyant image ensured the plane's influence in the pioneer era. And when the craze for homebuilt planes took off in the 1970s and 1980s, hobbyists rediscovered the Demoiselle's basic layout of a triangular fuselage and undercarriage rolled into one. Whenever a tiny ultralight takes off today, the ghost of the Demoiselle flies behind it, a testimony to its visionary inventor, who persevered through danger, accident, and illness to realize his dreams.
French Aeroplanes Before the Great War, by Leo Opdycke. Schiffer Military History, 1999.
Building Aeroplanes for Those Magnificent Men, by Allen C. Wheeler. Foulis, 1965.
More like a box kite with wheels than an airplane, the #14bis nevertheless made Santos famous as an aeronaut—that is, until Wilbur Wright showed up.
Designed for urban travel, the #9 Baladeuse often carried Santos into the heart of Paris, where he'd tied up before his favorite watering hole and have a drink.
Evan Hadingham is NOVA's senior science editor.
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