The 14-bis (French: Quatorze-bis; (Portuguese: Quatorze-bis; English: Fourteen-again, approximating "14B"), also known as Oiseau de proie ("bird of prey" in French), was a pioneer era, canard-style biplane designed and built by Brazilian aviation pioneer Alberto Santos-Dumont. In 1906, near Paris, the 14-bis made a manned powered flight that was the first to be publicly witnessed by a crowd and also filmed. It was the first powered flight by a non–Wright Brothers airplane aside from short powered "hops" by Clément Ader and Traian Vuia.
Background In June 1905, French aviator Gabriel Voisin had flown a glider towed by a fast boat on the Seine River, making a flight of over 150 metres (500 feet). The glider's wing and tail were made up of Hargrave cells, a box kite–like structure that provided a degree of inherent stability. This established the Hargrave cell as a configuration useful not only for kites but also for heavier-than-air aircraft. Santos-Dumont was living in Paris at the time, and was one of the most active "aeronauts" in Europe, having developed a series of non-rigid airships that displayed unparalleled agility, speed, endurance, and ease of control. Santos-Dumont met Voisin at the end of 1905, and commissioned him to help him construct an aircraft with the intention of attempting to win one of the prizes for heavier-than-air flights offered by the Aéro-Club de France to promote the development of heavier-than-air aviation in France. These included the Coupe Ernest Archdeacon prize of a silver trophy and 1,500 franc for the first flight of 25 m (82 ft) and another prize of 1,500 francs for the first flight of 100 m (330 ft).
Design Santos-Dumont supervised construction of a Hargrave-cell biplane powered by an Antoinette 8V V8 engine. The wings, each made up of three cells, were at the back and configured with pronounced dihedral to make the aircraft laterally stable. The 37-kilowatt (50-horsepower) Antoinette liquid-cooled, fuel-injected V8 engine was mounted at the extreme rear end of the fuselage, itself located almost vertically equidistant between the biplane wing panels' wing roots, with the rear-mount engine driving a pusher propeller, and the pilot stood in a wicker basket immediately in front of the engine. A movable box kite-style cell at the nose, pivoted on a universal joint within it and controlled by cables was intended for yaw and pitch control. This layout would later come to be called a "canard configuration". It was constructed from bamboo and pine joined by aluminium sockets and was covered with Japanese silk.
Operational history
The first trials of the aircraft were made on 22 July 1906 at Santos-Dumont's grounds at Neuilly, where it had been assembled. In order to simulate flight conditions, Santos-Dumont attached the aircraft under his latest non-rigid airship, the Number 14, which is why the aircraft came to be known as the "14-bis". The aircraft was then transported to the grounds of the Château de Bagatelle in the Bois de Boulogne, where there was more space. The forces imposed by the aircraft pulled dangerously at the airship's envelope, nearly tearing it and only allowing limited control. The danger of these tests caused Santos-Dumont and his team to quickly abandon them, although some useful information was obtained that led to adjustments in the balance and weight distribution of the aircraft. Further trials were made with the aircraft hung from a rope attached to pulleys running along a 60 m (200 ft) long steel cable slung between two posts, one 13.5 m (44 ft) high and the other 7 m (23 ft) high, much like a zip-line or tyrolienne of today. The first free-flight trials of the 14-bis took place at the Polo Ground in the Bois de Boulogne on 21 August, but were halted by damage to the newly fitted aluminium-bladed propeller, which replaced one with silk-covered wooden blades. After repairs another trial took place the following day; although the nosewheel left the ground, the aircraft had insufficient power to take off, and Santos-Dumont decided to replace the engine with an already proven 37 kW (50 hp) Antoinette 8V. Trials resumed on 4 September without great success, and on 7 September, after the propeller was damaged, a new slightly larger one was fitted.
On 13 September 1906 Aéro-Club de France observers gathered to witness an attempt to make a prize-winning flight. The aircraft failed to take off during a first attempt, but during the second it lifted and flew between 4 and 7 metres (13 and 23 ft) at an altitude of about 70 centimetres (28 in). The aircraft then landed in a nose-up attitude, breaking the propeller and bringing an end to the day's experiments. This brief flight did not qualify for any prize, but earned Santos-Dumont an ovation from the crowd. On 23 October, after a series of engine tests and high-speed ground runs (one of which ended as one wheel came loose, but this was quickly fixed), Santos-Dumont made a flight of over 50 metres (160 ft) at an altitude of 3–5 m (10–16+1⁄2 ft). This earned Santos-Dumont the first of the aviation prizes, 3,000 francs for a flight of 25 m (82 ft) or more.
This landing damaged the aircraft slightly, but Santos-Dumont announced that he should be ready to attempt the 100-metre (330 ft) prize on 12 November 1906.
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