The Wright brothers’ patents and their low importance for aviation


by Bogdan Lazar

(February 20, 2020)

The Wright brothers were two American inventors who claimed they built and piloted powered heavier-than-air flying machines in 1903, 1904, 1905 and May 1908 and really flew planes in front of numerous witnesses, including personalities of the aeronautic world, starting with August 8, 1908, when Wilbur, the elder of them, was seen up in the air above the Hunaudières racecourse near Le Mans, France. The article Le premier vol, en France, du premier homme oiseau” by François Peyrey (L’Auto, Paris, August 9, 1908, col. 1-2, p. 5) gives a detailed record of the flight performed the previous day and also mentions the names of a few eyewitnesses: Ernest Zens, who timed the flight at 1 minute and 45 seconds, Paul Zens, Ernest Archdeacon, Louis Blériot, René and Pierre Gasnier, Captain Léonide Sazerac de Forge, Count Henri de Moy, all members of the French Aéro-Club.

No technical drawing, detailed description or clear picture showing a Wright plane, on the ground or in the air, were made available to the general public before August 8, 1908, so none of the powered apparatuses constructed and flown before the above mentioned date, according to what the two inventors pretended, could have been a source of inspiration for other aviation pioneers because nobody knew exactly what those machines looked like. The French newspapers (see the examples listed below) started to show pictures of Wilbur’s biplane on August 12, 1908.

1908-08-12, “De nouveau, Wilbur Wright à volé”, L’Auto, Paris, August 12, 1908, col. 3-4, p. 1.

1908-08-12, Raoul Sabatier, “L’homme volant. Wilbur Wright a fait hier à 25 mètres de hauteur plus de Quatre kilomètres en 3 minutes 43 secondes.”, Le Journal, Paris, August 12, 1908, col. 3-4, p. 1.

1908-08-12, “Les expériences de Wright. Supériorité de l’aéroplane américain.”, Le Petit Parisien, Paris, August 12, 1908, col. 3-4, p. 2.

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1908-08-12, “La conquête de l’air. L’Aéroplane Wright.”, Le Radical, Paris, August 12, 1908, col. 3-4, p. 2.

All these papers contain at least one clear photo showing the Wright machine.

The first planes were officially witnessed taking off, under their own power, in France on September 13, 1906, and October 7, 1906, piloted by Santos Dumont and Traian Vuia, respectively. The aviation evolved rapidly and on January 13, 1908, Henri Farman already flew one kilometer in a circuit. Orville Wright even witnessed Farman flying on November 18, 1907, as can be seen from the article “Mr. Orville Wright Sees Mr. Henry Farman Compete for Deutsch-Archdeacon Prize” (New York Herald, Paris, November 19, 1907).

Pictures claimed by Orville Wright as made between December 17, 1903, and October 5, 1905, and showing three different planes (the 1903, 1904 and 1905 models) first appeared in print quite late, in “The Wright Brothers’ Aeroplane” by Orville and Wilbur Wright (The Century Magazine, New York, September 1908, Vol. LXXVI, No. 5, pp. 641-650).

The sole thing the two brothers from Dayton, Ohio, showed, before August 8, 1908, was a series of kites and gliders. These unpowered machines are the only ones that could have inspired the inventors who built planes and performed witnessed flights, beyond any doubt, from September 13, 1906 to August 8, 1908.  Here is a list with three important articles containing photos with these gliders in flight or on the ground:

1901-12, Wilbur Wright, “Some Aeronautical Experiments”, Journal of the Western Society of Engineers, Chicago, December 1901, Vol. VI, No. 6, pp. 489-510.

1903-08, Wilbur Wright, “Experiments and Observations in Soaring Flight”, Journal of the Western Society of Engineers, August 1903, Vol. VIII, No. 4, pp. 400-417.

1903-08, Octave Chanute, “La Navigation Aérienne aux États-Unis”, L’Aérophile, Paris, August 1903, 11e Année, No. 8, pp. 171-183.

Finally, Wilbur and Orville were granted a series of similar patents in: Great Britain (May 12, 1904), France (September 1, 1904), Austria (February 26, 1906), United States (May 22, 1906) and other countries. All of them just briefly point out the invention could also apply to planes but their texts plus accompanying drawings describe and show a glider. Later, starting with November 18, 1907, the two Daytonians filed other patents but again they do not show powered flying apparatuses.

Therefore, the case of the Wrights as the first people who built and flew planes is extremely weak and their 1903-1905 planes, as flight capable machines, which really traveled through the air carrying a pilot, are so elusive that their importance for powered aviation is zero.

The Wright gliders were so unstable that their rotations about the longitudinal and transverse axes had to be continuously controlled just to fly along straight lines. The main idea, in all their patents, is pitch and roll stability, not three-axis control. Also an objective clearly stated was “to provide efficient means of guiding the machine in both vertical and horizontal directions”, the Wrights do not claim steering. How the altitude could be changed is explained well. The front elevator has a double role, to stabilize the airplane in pitch and to change its height above the ground but regarding taking turns the short explanations given by the two inventors are not convincing. There is no indication in any of their patents that they understood the principle behind turning a plane/glider by banking, that they were aware of the important lateral centripetal force that appears. They do not say in any place that rolling the flying apparatus to one side will cause it to start making a turn.

As a remark, it was already known that heavier-than-air machines could be built in such a way that they were able to maintain their equilibrium automatically, without the continuous intervention of the operator. The article “Mechanical Flight. Wonderful Performance of Professor Langley’s Aerodrome.” (The Roanoke Daily Times, Virginia, US, May 13, 1896, col. 4, p. 8) contains a statement of Alexander Graham Bell regarding two flights of a model plane, actuated by a steam engine, he had witnessed on May 6, 1896. The inventor of the telephone was impressed by the stability of this apparatus during both its powered flight, while ascending, and as a glider, after the engine stopped. This is what he said:

“The aerodrome or flying machine, in question, was of steel, driven by a steam engine. It resembled an enormous bird, soaring in the air with extreme regularity in large curves, sweeping steadily upward in a spiral path, the spirals with a diameter of perhaps 100 yards, until it reached a height of about 100 feet in the air at the end of the course of about half mile.

“Then the steam gave out, the propellers which had moved it stopped and to my further surprise the whole, instead of tumbling down, settled as slowly and gracefully as it is possible for any bird to do, touched the water without any damage and was immediately picked out and ready to be tried again.

The description given by Bell proves that the automatic stability of planes or gliders was no longer an unsolved issue, as far back as 1896.

Another note would be about the May 1908 alleged flights and authentic pictures showing a Wright powered machine in the air. These photos, published on May 30, 1908, and taken by James H. Hare from the American magazine Collier’s, do not reveal anything new. They are apparently shot from a great distance and show a slightly modified 1902 glider. The engine and propellers are not visible. In their May 30, 1908, issues, Collier’s published one such image and the Scientific American two, in the following articles:

1908-05-30, Arthur Ruhl, “History at Kill Devil Hill. A Description of the First Flight of the Wright Brothers’ Aeroplane Witnessed by an Uninvited and Impartial Jury Representing the World at Large.”, Collier’s, New York, May 30, 1908, Vol. XLI, No. 10, pp. 18-19 and 26.

1908-05-30, “The Wright Aeroplane Test in North Carolina”, Scientific American, New York, May 30, 1908, Vol. XCVIII, No. 22, cover and p. 393.

This book is dedicated to the patents of the Wrights filled before August 8, 1908, in at least one country. They can be divided into five groups. To avoid accusations that I give citations out of context to make a point, I attached to this work the full text of at least one patent in each category. Only the versions published in Great Britain, France, Austria and United States are discussed and special attention is given to the patents granted in the United States, because they are in English and also contain, in general, more details than their foreign forms.

Patents related to the stabilization of an aeroplane in roll, using wing warping plus a vertical tail rudder, and in pitch, with a horizontal front elevator

1903-03-23 – 1906-05-22, Orville and Wilbur Wright, “US Patent No. 821,393 – Flying-Machine”, Filed: March 23, 1903, Patented: May 22, 1906, 10 pages.

1904-03-19 – 1904-05-12, Orville and Wilbur Wright, “GB Patent No. 6732, A.D. 1904 – Improvements in Aeronautical Machines”, Date of Application: 19th Mar., 1904, Accepted: 12th May, 1904, 5 pages.

1904-03-22 – 1904-09-01, Orville and Wilbur Wright, “French Patent No. 342.188 – Perfectionnements aux machines aéronautiques”, Filed: March 22, 1904, Delivered: July 1, 1904, Published: September 1, 1904, 4 pages.

1904-03-23 – 1906-02-26, Orville and Wilbur Wright, “Austrian Patent No. 23174 Flugmaschine”, Filed: March 23, 1904, Beginning of patent term: September 15, 1905, Issued: February 26, 1906, 3 pages.

They are all similar forms of the same application. The British, French and Austrian versions, which contain the same drawings, were made available to the public earlier but the American revision is more elaborate. All four have as their main subject the roll and pitch stabilization of gliders, pointing out, at the same time, the invention can also be used for powered machines. Neither they nor latter patents, first filled in 1907 or 1908, show drawings of motorized apparatuses. The main idea of all four is that an aeroplane type machine can be manually stabilized in roll and pitch by a pilot who continuously controls the position of its ailerons and front elevator. Because, once moved from their neutral location, the ailerons not only start turning the plane about its longitudinal axis but they also induce an unwanted rotation about the vertical axis (adverse yaw), the rear rudder of the glider or plane also moves, in correlation with the twist of the wings, in such a way as to counteract the above referred parasitic phenomenon.

Concerning this first and most important patent, more precisely its German version, filed on March 23, 1904, Harry Aubrey Toulmin (the Wright brothers’ patent lawyer) explained to Carl Pieper (his German correspondent), in a letter dated April 11, 1905, that the wing twisting and the vertical rudder had nothing to do with steering the machine. This document brings further evidence that the two brothers did not claim means by which the horizontal direction of flight could be changed. Here is the relevant excerpt of the letter:

“It is evident from the action of the German Patent Office that the invention is not yet understood by them. The entire purpose of the structure on which the application is based, excepting the front rudder, which is for another purpose, is to maintain the body of the structure level or parallel with the horizon. It has nothing whatever to do with steering, neither has it anything to do with the raising and lowering of the plane of flight. The setting of the two parallel edges of the supporting planes at different angles is solely for the purpose of maintaining the wide body of the machine parallel with the horizon. The rear rudder is solely for the purpose of overcoming the tendency to turn around a vertical axis which naturally results from setting the two edges of the planes at different angles. …

We shall trust to you to place these matters before the German Office in the best way possible and hope that you will be successful in obtaining the allowance of the application.” (H. A. Toulmin, “Letter to Carl Pieper”, Springfield, Ohio, April 11, 1905)

The explanation above nullifies any kind of pretentions that the Wrights invented the three-axis control system, as long as their patent application had “nothing whatever to do with steering”.

The aeroplane with two front vertical rudders, one fix and the other mobile

1907-11-18 – 1908-03-30, Wilbur and Orville Wright, “French Patent No. 384.124 – Perfectionnements aux machines aéronautiques”, Filed: November 18, 1907, Delivered: January 27, 1908, Published: March 30, 1908, 8 pages.

1908-02-17 – 1914-12-29, Orville and Wilbur Wright, “US Patent No. 1,122,348 – Flying-Machine”, Filed: February 17, 1908, Patented: December 29, 1914, 10 pages.

1908-11-10 – 1909-04-01, Wilbur and Orville Wright, “GB Patent No. 24,076, A.D. 1908 – Improvements in or connected with Flying Machines”, Date of Application: November 10, 1908, Accepted: April 1, 1909, 12 pages.

All three are closely related to the first group. The French and British versions were published first but the American variant contains again more details. The element of novelty, they came with, was the introduction of two additional vertical rudders, one fix, the other mobile, both of them placed in front of the main wings. Their principal purpose was to provide the pilot with better means for counteracting that adverse yaw which appeared when the wings were twisted for stabilizing the plane in roll.

Two vertical vanes placed close to the tips of the main wings

1907-11-18 – 1908-03-30, Wilbur and Orville Wright, “French Patent No. 384.125 – Perfectionnements aux machines aéronautiques”, Filed: November 18, 1907, Delivered: January 27, 1908, Published: March 30, 1908, 6 pages.

1908-02-17 – 1911-03-21, Orville and Wilbur Wright, “US Patent No. 987,662 – Flying-Machine”, Filed: February 17, 1908, Patented: March 21, 1911, 5 pages.

1908-02-24 – 1909-03-10, Wilbur and Orville Wright,Austrian Patent No. 36566 Drachenflieger”, Filed: February 24, 1908, Beginning of patent term: October 15, 1908, Issued: March 10, 1909, 4 pages.

1908-11-10 – 1909-02-18, Wilbur and Orville Wright, “GB Patent No. 24,077, A.D. 1908 – Improvements in or connected with Flying Machines”, Date of Application: November 10, 1908, Accepted: February 18, 1909, 7 pages.

They are again four roughly identical patents. This time, for counteracting the same parasitic effect already explained, the Wrights imagined two vertical rudders placed close to the tips of the main wings. Their principal purpose was to equalize the uneven drag the wingtips encountered when they were twisted in opposite directions and in consequence to prevent the rotation of the aeroplane about its vertical axis.

The automatic pitch and roll stabilizers, two fallacies

1908-02-10 – 1913-10-14, Orville and Wilbur Wright, “US Patent No. 1,075,533 – Flying-Machine”, Filed: February 10, 1908, Patented: October 14, 1913, 14 pages.

1909-02-06 – 1909-09-09, Orville and Wilbur Wright, “GB Patent No. 2913, A.D. 1909 – Improvements in or connected with Flying Machines”, Date of Application: February 6, 1909, Accepted: September 9, 1909, 19 pages.

1909-02-08 – 1909-09-21, Wilbur and Orville Wright, “French Patent No. 401.905 – Perfectionnements aux machines volantes”, Filed: February 8, 1909, Delivered: August 14, 1909, Published: September 21, 1909, 17 pages.

This set of three identical patents, containing the same drawings, is about two mechanisms the Wrights regarded as capable of stabilizing an aeroplane in roll and pitch, respectively. In reality, both of them are fallacies and cannot work.

The brothers believed the rod of a pendulum always tends to align to the vertical of the place. This reasoning is correct if the acceleration of the suspension point is zero, which, unfortunately, is not the case inside a plane. In consequence, the orientation of a pendulum rod, able to rotate about a fix pivot placed somewhere in a flying glider or powered machine, cannot be used as a reference that shows the vertical and so it is useless in correcting the roll of an airplane about its longitudinal axis.

Regarding the pitch stabilization, the Wrights also believed that a system, imagined by them and driven by a wind vane (two version were proposed), could keep an aeroplane fly horizontally or along a straight course set by the operator. In reality the brothers’ vanes would have rested in the same position, relative to the plane, for a variety of situation in which the apparatus climbed, descended or flied parallel to the ground. Therefore, the position of the vane could not have been used as a reference able to indicate the horizontal.

The Flexible rudder

1908-07-15 – 1909-01-05, Orville and Wilbur Wright, “US Patent No. 908,929 – Mechanism for Flexing the Rudder of a Flying Machine or the Like”, Filed: July 15, 1908, Patented: January 5, 1909, 5 pages.

1909-07-08 – 1909-12-14, Wilbur and Orville Wright, “French Patent No. 404.866 – Perfectionnements au mécanisme servant présenter un gouvernail de machine aéronautique sous une forme concave”, Field:  July 8, 1909, Delivered: October 30, 1909, Published: December 14, 1909.

1909-07-09 – 1909-08-05, Orville and Wilbur Wright, “GB Patent No. 16,068, A.D. 1909 – Improvements in Mechanism for Actuating the Rudders or Controlling Planes of Aeronautical Machines”, Date of Application: July 9, 1909, Accepted: August 5, 1909, 5 pages.

These three identical documents have as their object a mechanism for flexing the rudder of a flying machine for the purpose of modifying its lift. As a remark, the British and French patents of 1904 plus their Austrian and US versions granted in 1906 all show a drawing, the same, presenting a flexible front elevator.


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