Blériot XI

Blériot XI
Thulin A (licence-built Blériot XI)
Role Civil tourer/trainer/military
Manufacturer Louis Blériot
Designer Louis Blériot and Raymond Saulnier
First flight 23 January 1909




The Blériot XI `is a French aircraft which was used by Louis Blériot to make the first flight across the English Channel in a heavier-than-air aircraft on 25 July 1909. This achievement is one of the most famous accomplishments of the pioneer era of aviation, and not only won Blériot a lasting place in history but also assured the future of his aircraft manufacturing business. The event caused a major reappraisal of the importance of aviation; the English newspaper The Daily Express led its story of the flight with the headline "Britain is no longer an Island".[1]

It was produced in both single- and two-seat versions, powered by a number of different engines and was widely used for competition and training purposes. Military versions were bought by many countries, continuing in service until after the outbreak of World War I in 1914. Two restored examples — one in the United Kingdom and one in the United States — of original Blériot XI aircraft are thought to be the two oldest flyable aircraft in the world.

Design

Closeup of the original Bleriot XI's main landing gear
Blériot XI as first built: note small "teardrop" profile fin on cabane

The Blériot XI, largely designed by Raymond Saulnier,[2] was a development of the Blériot VIII, which Blériot had flown successfully in 1908. Like its predecessor, it was a tractor-configuration monoplane with a partially covered box-girder fuselage built from ash with wire cross bracing. The principal difference was the use of wing warping for lateral control. The tail surfaces consisted of a small balanced "all-moving" rudder mounted on the rearmost vertical member of the fuselage and a horizontal tailplane mounted under the lower longerons. This had elevator surfaces making up the outermost part of the fixed horizontal surface; these "tip elevators" were linked by a torque tube running through the inner section. The bracing and warping wires were attached to a dorsal cabane consisting of a pair of inverted V struts with their apexes connected by a longitudinal tube and an inverted four-sided pyramidal ventral cabane, also of steel tubing, below. When first built it had a wingspan of 7 m (23 ft) and a small teardrop-shaped fin mounted on the cabane,[3] which was later removed.

Like its predecessor, it had the engine mounted directly in front of the leading edge of the wing and the main undercarriage was also like that of the Type VIII, with the wheels mounted in castering trailing arms which could slide up and down steel tubes, the movement being sprung by bungee cords. This simple and ingenious design allowed crosswind landings with less risk of damage. A sprung tailwheel was fitted to the rear fuselage in front of the tailplane, with a similar castering arrangement.

When shown at the Paris Aero Salon in December 1908, the aircraft was powered by a 26 kW (35 hp) 7-cylinder R.E.P. engine driving a four-bladed paddle-type propeller. The aircraft was first flown at Issy-les-Moulineaux on 23 January 1909,[4] but although the aircraft handled well, the engine proved extremely unreliable and, at the suggestion of his mechanic Ferdinand Collin, Blériot made contact with Alessandro Anzani, a famous motorcycle racer whose successes were due to the engines that he made, and who had recently entered the field of aero-engine manufacture. On 27 May 1909, a 19 kW (25 hp) Anzani 3-cylinder fan-configuration (semi-radial) engine was fitted.[5] The propeller was also replaced with a Chauvière Intégrale two-bladed propeller made from laminated walnut wood. This propeller design was a major advance in French aircraft technology and was the first European propeller to rival the efficiency of the propellers used by the Wright Brothers.[6]

During early July, Blériot was occupied with flight trials of a new aircraft, the two-seater Type XII, but resumed flying the Type XI on 18 July. By then, the small cabane fin had been removed and the wingspan increased by 79 cm (31 in). On 26 June, he managed a flight lasting 36 minutes 55 seconds, and on 13 July, Blériot won the Aero Club de France's first Prix du Voyage with a 42 km (26 mi) flight between Etampes and Orléans.[7]

The Channel crossing

Blériot over the English Channel, 25 July 1909

The Blériot XI gained lasting fame on 25 July 1909, when Blériot crossed the English Channel from Calais to Dover, winning a £1,000 prize awarded by the Daily Mail. For several days, high winds had grounded Blériot and his rivals: Hubert Latham, who flew an Antoinette monoplane, and Count de Lambert, who brought two Wright biplanes. On 25 July, when the wind had dropped in the morning and the skies had cleared, Blériot took off at sunrise. Flying without the aid of a compass, he deviated to the east of his intended course, but, nonetheless, spotted the English coast to his left. Battling turbulent wind conditions, Blériot made a heavy "pancake" landing, nearly collapsing the undercarriage and shattering one blade of the propeller, but he was unhurt. The flight had taken 36.5 minutes and had made Blériot a celebrity, instantly resulting in many orders for copies of his aircraft.

The aircraft, which never flew again, was hurriedly repaired and put on display at Selfridges department store in London. It was later displayed outside the offices of the French newspaper Le Matin and eventually bought by the Musee des Arts et Metiers in Paris.

Subsequent history

After the successful crossing of the English Channel, there was a great demand for Blériot XIs. By the end of September 1909, orders had been received for 103 aircraft.[8] After an accident at an aviation meeting in Istanbul in December 1909, Blériot gave up competition flying, and the company's entries for competitions were flown by other pilots, including Alfred Leblanc, who had managed the logistics of the cross-channel flight, and subsequently bought the first production Type XI, going on to become one of the chief instructors at the flying schools established by Blériot.

In February 1912 the future of the Type XI was threatened by the French army placing a ban on the use of all monoplanes. This was the result of a series of accidents in which Blériot aircraft had suffered wing failure in flight. The first of these incidents had occurred on 4 January 1910, killing Léon Delagrange, and was generally attributed to the fact that Delagrange had fitted an over-powerful engine, so overstressing the airframe. A similar accident had killed Peruvian pilot Jorge Chavez at the end of 1910 at the end of the first flight over the Alps, and in response to this the wing spars of the Blériot had been strengthened. A subsequent accident led to a further strengthening of the spars.[9] Blériot, understandably, took this matter very seriously, and produced a report for the French government which came to the conclusion that the problem was not the strength of the wing spars but a failure to take into account the amount of downward force to which aircraft wings could be subjected, and that the problem could be solved by increasing the strength of the upper bracing wires. This analysis was accepted, and Blériot's prompt and thorough response to the problem enhanced rather than damaged his reputation.[9]

Further development

The Type XI remained in production until the outbreak of the First World War, and a number of variations were produced. Various types of engine were fitted, including the 120° Y-configuration, "full radial" three-cylinder Anzani (like the restored example at Old Rhinebeck Aerodrome still flies with) and the 37 kW (50 hp) and 52 kW (70 hp), seven cylinder Gnome rotary engines. Both single and two-seat versions were built, and there were variations in wingspan and fuselage length. In later aircraft the tip elevators were replaced by a more conventional trailing edge elevator, the tailwheel was replaced by a skid, and the former "house-roof" five-member dorsal cabane being replaced by a simpler, four-sided pyramidally framed unit similar to the ventral arrangement for the later rotary-powered versions. Blériot marketed the aircraft in four categories: trainers, sport or touring models, military aircraft, and racing or exhibition aircraft.

Civil use

The Type XI took part in many competitions and races. In August 1910 Leblanc won the 805 km (500 mi) Circuit de l'Est race, and another Blériot flown by Emile Aubrun was the only other aircraft to finish the course.[10] In October 1910, Claude Grahame-White won the second competition for the Gordon Bennett Trophy flying a Type XI fitted with a 75 kW (100 hp) Gnome, beating a similar aircraft flown by Leblanc, which force-landed on the last lap. During the race Leblanc had established a new world speed record.[11] In 1911, Andre Beaumont won the Circuit of Europe in a Type XI and another, flown by Roland Garros, came second.

Anzani engined Blériot XI similar to the aircraft used for the Channel flight
Detail of replica Blériot XI wing, Hamburg Airport Days, 2007

Louis Blériot established his first flying school at Etampes near Rouen in 1909. Another was started at Pau, where the climate made year-round flying more practical, in early 1910 and in September 1910 a third was established at Hendon Aerodrome near London. A considerable number of pilots were trained: by 1914 nearly 1,000 pilots had gained their Aero Club de France license at the Blériot schools, around half the total number of licences issued.[12] Flight training was offered free to those who had bought a Blériot aircraft: for others it initially cost 2,000 francs, this being reduced to 800 francs in 1912. A gifted pupil favoured by good weather could gain his license in as little as eight days, although for some it took as long as six weeks. There were no dual control aircraft in these early days, training simply consisting of basic instruction on the use of the controls followed by solo taxying exercises, progressing to short straight-line flights and then to circuits. To gain a license a pilot had to make three circular flights of more than 5 km (3 mi), landing within 150 m (490 ft) of a designated point.[13]

Military use

The first Blériot XIs entered military service in Italy and France in 1910, and a year later, some of those were used in action by Italy in North Africa (the first use of aircraft in a war) and in Mexico.[14] The British Royal Flying Corps received its first Blériots in 1912. During the early stages of World War I, eight French, six British and six Italian squadrons operated various military versions of the aircraft, mainly in observation duties but also as trainers, and in the case of single-seaters, as light bombers with a bomb load of up to 25 kg.

Famous Blériot Monoplane pilots

Oskar Bider starting from Bern to his flight over the Alps, showing the pyramidal dorsal cabane of later Bleriot XI examples

Variants

Blériot XI (REP)
1908, the first Type XI, powered by a 22 kW (30 hp) REP engine, displayed at the 1908 Paris Salon Exposition, first flown at Issy on 18 January 1909.[38]
Blériot XI (Anzani)
1909, the first aircraft re-engined with a 19 kW (25 hp) Anzani engine and with wings enlarged from 12 to 14 m2 (130 to 150 sq ft). Fitted with a flotation bag for Blériot's cross channel flight.[38]
Blériot XI Militaire
Military single-seater, powered by a 37 kW (50 hp) Gnome engine.[38]
Blériot XI Artillerie
Very similar to the Militaire version, but with a fuselage divided into two sections so that it could be folded for transport.[38]
Blériot XI E1
Single-seat training version.
Blériot XI Type Ecole
A trainer with considerable wing dihedral looped cane tailskid, tip elevators and other modifications.[38]
Blériot XI R1 Pinguin
Rouleur or ground training aircraft, fitted with clipped wings and a wide-track undercarriage with a pair of forward-projecting skids to prevent nose-overs. Some examples were fitted with a 26 kW (35 hp) Anzani engine and others with old 37 kW (50 hp) Gnome engines that were no longer producing their full power output.[38]
Blériot XI (1912)
From March 1912 with two-piece elevators and high fuselage skid.[38]
Blériot XI Parasol
aka Blériot-gourin, modified by Lieutenant Gouin and Henri Chazal with a parasol wing and split airbrake/rudder.[38]
Blériot XIbis
In January 1910 the bis introduced more conventional tail feathers and elliptical elevators with a half-cowled Gnome engine.[38]
Blériot XI-2 Tandem
Standard tandem 2-seat touring, reconnaissance, training model, powered by a 52 kW (70 hp) Gnome 7B rotary piston engine.[38]
Blériot XI-2 bis "côte-à-côte"
Blériot XI-2 bis
February 1910 2-seat model, with side-by-side seating and a non-lifting triangular tailplane with semi-elliptical trailing-edge elevators, with several variations such as floats extended nose, modified tail-skid and other changes.[38] (Length 8.32 m (27.3 ft), Wingspan 10.97 m (36.0 ft)[39]
Blériot XI-2 Hydroaeroplane
Two-seater floatplane with wingspan of 11 m (36 ft) powered by a 60 kW (80 hp) Rhône engine.[40] First flown with an extended rudder with a float on the bottom: this was later replaced by a standard rudder and a float fitted under the rear fuselage.[38]
Blériot XI-2 Artillerie
Military 2-seat model, powered by a 52 kW (70 hp) Gnome rotary piston engine. Two aircraft or versions of the same aircraft with differing elevators.
Blériot XI-2 Génie
Military version, designed for easy transport, it could be broken down/reassembled in 25 minutes.[38]
Blériot XI-2 Vision totale
XI-2 modified with a parasol wing in July 1914.[38]
Blériot XI-2 Hauteur
Powered by an 60 kW (80 hp) Gnome rotary piston engine and used by roland Garros in altitude record flights in August 1912 and March 1913.[38]
Blériot XI-2 BG
Two-seat high-wing parasol model.
Blériot XI-3 Concours Militaire
Tandem 3-seat model, powered by a twin-row 14-cylinder, 100 kW (140 hp) Gnome Double Lambda rotary engine. Span 11.35 m (37 ft 3 in), length 8.5 m (28 ft)[38][41]
Thulin A
Licence-built in Sweden

Military operators

Blériot XI
 Argentina
 Australia
 Belgium
 Bolivia
 Brazil
 Bulgaria
 Chile
 Denmark
 France
 Greece
 Guatemala
 Kingdom of Italy
 Japan
 Mexico
 Norway
Norwegian Army Air Service. One only: Tryggve Gran's
 New Zealand
Royal New Zealand Air Force. One aircraft named "Brittania"; it was in service from 1913 to 1914.
 Romania
 Russia
Blériot XI used by Serbia, 1915
Kingdom of Serbia Serbia
 Sweden
  Switzerland
 Ottoman Empire
Blériot XI with RFC markings during WW1
 United Kingdom
 Uruguay

Survivors

The original Blériot XI on which Louis Blériot crossed the Channel in 1909 in the Musée des Arts et Métiers, Paris.

In addition to the aircraft used by Louis Blériot to make his cross-channel flight in 1909, on display in the Musée des Arts et Métiers in Paris, a number of examples have been preserved. Both the British and American restored-to-airworthiness examples, each now over a century old and believed to be the two oldest flyable aircraft anywhere on Earth, are usually only "hopped" for short distances due to their uniqueness.

Airworthy aircraft

Maiden public flight by a Blériot XI, manufactured 1918 under license by AB Thulinverken (AETA) in Landskrona, Sweden as type Thulin A. Photo: Bengt Oberger.

Display aircraft

Specifications (Blériot XI)

Data from [51]

General characteristics

Performance

References

Notes

  1. "The Wider View: 100 years after Blériot first flew across the Channel, an identical plane repeats the feat (but not before the French had blocked the first attempt)." The Daily Express, 26 July 2009. Retrieved: 8 January 2012.
  2. Elliott 2000, p. 142.
  3. "Blériot No.9"'Flight 9 January 1909
  4. "Bleriot Flies His Short-Span Machine." Flight, 30 February 1909.
  5. Elliott 2000, p. 73.
  6. Gibbs-Smith, C.H., Aviation. London: NMSO, 2003, p. 150.
  7. Eliott 2000, p. 96.
  8. "M. Bleriot's Plans." Flight', 25 September 1909.
  9. 1 2 Monoplane FailuresFlight 30 March 1912
  10. "The Circuit de l'Est." Flight, 27 August 1910.
  11. Villard 1987, p. 86
  12. Elliott 2000, p. 173.
  13. Elliott 2000, p. 171.
  14. "Bleriot XI." Secretaría de la Defensa Nacional. Retrieved: 17 July 2010.
  15. "Otto Britschgi." AeroRevue via azimut270.ch, October 2007. Retrieved: 14 January 2012.
  16. Mulder, Rob. "Timeline of Civil Aviation in Norway." europeanairlines.no, 6 January 2011. Retrieved: 14 January 2012.
  17. Warth, John. "Adventurers of the Air" Smithsonian Institution. Retrieved: 16 January 2012.
  18. "Flying the Irish Channel" Flight Volume IV, Issue 17, p. 379. Retrieved: 16 January 2012.
  19. "Aero Club of France: Leon Delagrange." Flight, 4 February 1911, p. 88. Retrieved: 16 January 2012.
  20. http://www.airspacemag.com/daily-planet/the-worlds-first-warplane-115175678/?no-ist=
  21. "John Domenjoz, 1886–1952: le roi de la voltige aérienne entre 1913 et 1920 vidéo" (in French). Pionnair-ge.com. Retrieved: 17 July 2010.
  22. Cooper, Ralph. "John Domenjoz." earlyaviators.com, 2010. Retrieved: 29 October 2010.
  23. "Garros Regains the Height Record." Flight, 4 September 1912. Retrieved: 26 April 2012.
  24. "The American International Meeting"Flight International 5 November 1910
  25. Cooper, Ralph. "Eugene Gilbert." EarlyAviators.com. Retrieved: 8 January 2012.
  26. "Tryggve Herman Gran" (in Norwegian). Store norske leksikon. Retrieved: 8 January 2012.
  27. Parnell, Neville and Boughton, Trevor, Flypast Australian Government Publishing Service, Canberra, 1988, page 21 ISBN 0 644 07918 5
  28. "The First Aerial Post: Hendon to Windsor & Windsor to Hendon." Thamesweb. Retrieved: 8 January 2012.
  29. "Vasily Kamensky." russia-ic.com. Retrieved: 8 January 2012.
  30. Horáková, Pavla. "First Czech aviator Jan Kaspar died 75 years ago." Czech Radio, 1 February 2002. Retrieved: 8 January 2012.
  31. "The World Speed Record"Flight 25 May 1951
  32. "Jan Olieslagers." The Aerodrome, 2011. Retrieved: 8 January 2012.
  33. The New York Times, 23 July 1936. Retrieved: 8 January 2012.
  34. "Adolphe Pégoud." The Aerodrome, 2011. Retrieved: 8 January 2012.
  35. Koontz, Giacinta Bradley. "Harriet Quimby." harrietquimby.org, 2010. Retrieved: 17 July 2010.
  36. Villard 2002, p. 116.
  37. "Emile Taddéoli." AeroRevue via azimut270.ch, October 2007. Retrieved: 14 January 2012.
  38. 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 Opdycke, Leonard E. (1999). French Aeroplanes before the Great War. Atglen: SchifferPublishing Limited. ISBN 0 7643 0752 5.
  39. "The Bleriot 2-Seater Monoplane, Type XI 2 bis." Flight, 31 December 1911.
  40. "The New Blériot Hydro-Aeroplane." Flight, 28 November 1913. Retrieved: 26 April 2012.
  41. "Nassau Boulevard Meeting." Flight, 24 October 1911.
  42. "Museo Nacional de Aeronáutica (in Spanish)." museonacionaldeaeronauticamoron, 16 February 2011. Retrieved: 15 January 2012.
  43. "Blériot XI." Archived 5 January 2012 at the Wayback Machine. National Air and Space Museum, Smithsonian. Retrieved: 15 January 2012.
  44. "Blériot XI". Royal Air Force Museum. Retrieved 20 October 2013.
  45. Holcomb, Kevin. "Surviving Bleriot XI's." Holcomb's Aerodrome. Retrieved: 15 January 2012.
  46. "Blériot XI." Canada Aviation and Space Museum. Retrieved: 15 January 2012.
  47. Stoff, Joshua. "The Blériot #153 Comes to The Cradle of Aviation Museum." The Cradle of Aviation Museum. Retrieved: 15 January 2012.
  48. Bleriot XI "Cross Country" Old Rhinebeck Aerodrome Retrieved: February 28, 2014.
  49. Thompson, Stephen. "1914 Bleriot XI Monoplane." Migration Heritage Centre, 2011. Retrieved: 15 January 2012.
  50. "Hangar 1 del Museo de Aeronáutica y Astronáutica" (in Spanish). Museo del Ejército del Aire. Retrieved 20 October 2013.
  51. Angelucci 1983, p. 20.

Bibliography

  • Angelucci, Enzo. The Rand McNally Encyclopedia of Military Aircraft, 1914–1980. San Diego, California: The Military Press, 1983. ISBN 0-517-41021-4.
  • Charlson, Carl and fr:Christian Cascio, directors. A Daring Flight (DVD). Boston: WGBH Boston Video, 2005.
  • Crouch, Tom D. Blériot XI: The Story of a Classic Aircraft. Washington, D.C.: Smithsonian Institution Press, 1982. ISBN 978-0-87474-345-6.
  • Elliott, Bryan A. Blériot: Herald Of An Age. Stroud, Gloucestershire: Tempus, 2000. ISBN 0-7524-1739-8.
  • Munson, Kenneth. Bombers, Patrol and Reconnaissance Aircraft 1914–1919 (Blandford Colour Series). London: Associate R.Ae.S., 1977. ISBN 0-7137-0632-8
  • Villard, Henry Serrano. Blue Ribbon of the Air. Washington: Smithsonian Press, 1987. ISBN 0-87474-942-5.
  • Villard, Henry Serrano. Contact! The Story of the Early Aviators. Boston: Dover Publications, 2002. ISBN 978-0-486-42327-2.
  • Vivien, F. Louis. "Description détaillée du monoplan Blériot" (in French). Paris: librairie des Sciences aéronautiques, 1905. (Original 1911 AVIA book French book with Blériot XI characteristics and specifications).

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