Santos-Dumont 14-bis

For the Brazilian band, see 14 Bis (band).
14-bis
Role Experimental aircraft
Manufacturer Alberto Santos-Dumont
Designer Alberto Santos-Dumont
First flight September 7, 1906
Number built 1


The 14-bis (Quatorze-bis), also known as Oiseau de proie ("bird of prey" in French),[1] was a pioneer era canard biplane designed and built by Brazilian aviation pioneer Alberto Santos-Dumont. The aircraft made the first publicly witnessed European manned flights by a powered heavier-than-air machine.

Background

In June 1905 Gabriel Voisin tested a glider by having it towed by a fast boat on the River Seine, making a flight of over 150 m (500 ft). 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.[2] 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.[3] These included the Coupe Ernest Archdeacon prize of a silver trophy and 1500 francs for the first flight of 25 m (82 ft) and another prize of 1500 francs for the first flight of 100 m (330 ft).[4]

Design

Accordingly, Santos-Dumont had a Hargrave-cell (box kite-like) biplane powered by an Antoinette 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 18 kW (24 hp) 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 balloon basket immediately in front of the engine. A movable boxkite-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.[5]

Operational history

The 14-bis at the Château de Bagatelle grounds, suspended from the envelope of Santos-Dumont's No.14 airship.

The first trials of the aircraft were made at Santos-Dumont's grounds on 22 July 1906 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. Due to this, the aircraft came to be known as the "14-bis".[6] 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,[7] 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.[8] 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 a 37 kW (50 hp) Antoinette.[8] Trials resumed on 4 September without great success, and on 7 September after the propeller was damaged a new slightly larger one was fitted.[9]

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 cm (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.[8]

On the 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 m (160 ft) at an altitude of 3–5 m (9.8–16.4 ft).[10] This earned Santos-Dumont the first of the aviation prizes, 3,000 francs for a flight of 25 m (82 ft) or more.

The 14-bis flying over Bagatelle grounds on October, 23th.
Monument at Bagatelle to Santos-Dumont's flight of November 12th and its first world records.

This landing damaged the aircraft slightly and it required more repairs, but Santos-Dumont announced that he should be ready to attempt the 100 meters prize on 12 November. The 14-bis was repaired, and octagonal ailerons were added to the middle of each outermost wing cell, with the surfaces pivoting between the outermost forward struts. The ailerons were operated by cables attached to the shoulders of the pilot's flightsuit, somewhat like the hip-movement wing-warping control on the Wright Flyer. On the morning of 12 November 1906 the aviation community of France assembled at the Chateau de Bagatelle's grounds to witness Santos Dumont's next attempt. As Santos-Dumont allowed the 14-bis to run down the field, a car drove alongside, from which Henry Farman dropped a plate each time he observed the wheels of the aircraft leave the ground or touch down again. The first attempt achieved a 5-second flight of about 40 m (130 ft) around 40 cm off the ground, and the second two brief flights of 40 and 50 m (160 ft). A hurried landing due to the proximity of some trees after this second attempt damaged the wheel axles, and these were fixed during a lunch break. In the afternoon, further flights of 50 meters and then 82 m (269 ft) (achieving about 40 km/h), this one interrupted by the proximity of a polo barrier. As the sun set, Santos-Dumont attempted one more flight. In order to ensure he would not hit the spectators, who by this time were all over the field, he pulled up while flying over them. After 22 seconds, he cut the engine and glided in to land. He had flown for 220 meters (over 700 ft), qualifying for the second aviation prize offered for heavier-than-air-aircraft, 1,000 francs for a flight of 100 meters or more. This was the last recorded flight of the aircraft.[11] The next notable Santos-Dumont flights were made in November 1907, flying his No. 19 Demoiselle[12]

14-bis vs. Wright Flyer

Some people claim that the 14-bis rather than Wright Flyer was the first true airplane.[13] For takeoff the 1903 Wright Flyer used a launch rail and a wheeled dolly which was left on the ground; the airplane landed on skids. After 1903 the Wrights used a catapult to assist most takeoffs of their 1904 and 1905 airplanes. The Santos-Dumont 14-bis did not use a catapult and ran on rear-located mainwheels, with a "nose skid" under the forward fuselage.

The Fédération Aéronautique Internationale (F.A.I) ("International Federation of Aeronautics"), founded in France in 1905 to "regulate the sport of flying" and to keep track of aviation records and other aeronautical activities, stated among its rules that an aircraft should be able to take off under its own power in order to qualify for a record. Therefore, many Brazilians believe the 14-bis was the first operational fixed-wing aircraft. Written and photographic documentation by the Wrights authenticated by historians show that the 1903 Wright Flyer accomplished takeoffs in a strong headwind without a catapult and made controlled and sustained flight nearly three years before Santos Dumont made his first takeoff. Official records and motion picture footage show that the 14-bis achieved unaided takeoff on wheels.

Specifications

Data from www.aviafrance.com[14]

General characteristics

Performance

Media

References

Notes
  1. ↑ Bruce, Stuart E. Mechanical Flight Flight, 20 February 1909, p.108
  2. ↑ Gibbs-Smith 1974, p.160
  3. ↑ Wykeham 1962, pp202-3
  4. ↑ Gibbs-Smith 1974, p. 137.
  5. ↑ Gibbs-Smith 974, p. 212
  6. ↑ Le Aéroplane Santos-Dumont l'Aérophile, July 1906, p.167
  7. ↑ Le Aéroplane Santos-Dumont l'Aérophile, July 1906, pp.168-9
  8. 1 2 3 L'Essor de Santos-Dumont l'Aérophile, September 1906, pp.191-4
  9. ↑ Gibbs-Smith 1874, p.218
  10. ↑ La Deuxième envolée de Santos-Dumont L'Aérophile October 1906, p.245
  11. ↑ Flight, 1909, p. 12.
  12. ↑ "l'Aéroplane Santos=Dumont No. 19". l'Aérophile (in French): 314. November 1907.
  13. ↑ "The Case for Santos-Dumont". wright-brothers.org. Retrieved 9 May 2014.
  14. ↑ http://www.aviafrance.com/santos-dumont-14-bis-aviation-france-9613.htm
Bibliography

External links

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