Wrights, 1908, The Wright Brothers' aeroplane

Orville and Wilbur Wright, "The Wright Brothers' Aëroplane"; The Century Magazine Vol. LXXVI, No. 5; September, 1908; pp. 642–650.

Billed as the Wrights' first detailed popular account of their experiments.

Background

They write that their interest in aeronautics goes back to autumn 1878, when their father brought home a toy rubber-band "helicoptère" (which they called a bat). Several years later they started building their own "bats" and found that the bigger they built, the less the bat flew. They also enjoyed kite-flying.

Theoretical study

As adults, they got involved once more after hearing in summer 1896 of the death of Otto Lilienthal. They read Chanute, 1894, Progress in Flying Machines, Langley, 1891, Experiments in Aerodynamics, all three volumes of the Aeronautical Annual (for some reason these are mis-dated by 10 years as 1905, 1906,1907), and "several pamphlets published by the Smithsonian Institution, especially articles by Lilienthal and extracts from Mouillard's 'Empire of the Air'".

[Note: Richard Rathbun is credited with sending them a lot of this info from the Smithsonian; see Wilbur Wright to Smithsonian Institution 30-May-1899.]

They divide the field of aviation into two schools: the Langley-Maxim school of powered flight, and the Lilienthal-Mouillard-Chanute school of soaring; they sympathized with the latter. They identified stability as the foremost problem and saw that many had tried to lower the center of gravity of aircraft in an attempt to achieve the greatest balance.

They preferred to arrange the wings in a V shape, forming a dihedral angle, "with the center low and the wing-tips elevated". They write: "In theory this was an automatic system, but in practice it had two serious defects: first, it tended to keep the machine oscillating; and, second, its usefulness was restricted to calm air."

They also used a V-shape from front-to back, with the body of the aircraft at a positive angle and the tail at a negative angle, with the center of gravity far forward. Again, the result would be instability in wind.

So instead of trying to build an airplane that would "tend to right itself" they tried to "make it as inert as possible to the effects of change of direction or speed, and thus reduce the effects of wind-gusts to a minimum." They set out to do this by changing the shape of the aeroplane and "by arching the surfaces from tip to tip, just the reverse of what our predecessors had done."

They considered steering by movement of the operator's body (per Lilienthal and Chanute) too cumbersome and limited. Instead they wanted a system for changing wing position. Thus they came to wing warping and rudders for navigation.

A happy device was discovered whereby the apparently rigid system of superposed surfaces, invented by Wenham, and improved by Stringfellow and Chanute, could be warped in a most unexpected way, so that the aëroplanes could be presented on the right and left sides at different angles to the wind.

They describe a period of disappointment for aviation (1885–1900), in which Maxim gave up, Ader's machine didn't work, Lilienthal and Pilcher were killed, "and Chanute and many others, from one cause or another, had relaxed their efforts, though it subsequently became known that Professor Langley was still secretly at work on a machine for the United States Government."

Experiments in North Carolina

"We began our active experiments at the close of this period, in October, 1900, at Kitty Hawk, North Carolina."

[Note: This date is less than 1.5 years after receiving the information packet from the Smithsonian; rather towards the end of the five-year period they identify.]

First they tested their aircraft as kites to be flown in wind; manned, then unmanned.

In 1901 they met Octave Chanute, who visited them for several weeks at Kill Devil Hill, and witnessed a power flight near Dayton in October 1904.

The aircraft they were testing in 1901 was built after the fashion of Lilienthal, with parabolic curve (1/12 the depth of its length) from front to back. They increased the area from 165 square feet to 306 square feet ("a size much larger than Lilienthal, Pilcher, or Chanute had deemed safe"). This aircraft fell far short of expectations, leading them to suspect an error in the tables they were using.

Then they shifted to gliding, "coasting down hill on the air", and soon made glides of 300 feet or more, in wind up to 27 miles/hour.

We found that, contrary to the teachings of the books, the center of pressure on a curved surface traveled backward when the surface was inclined, at small angles, more and more edgewise to the wind. We also discovered that in free flight, when the wing on one side of the machine was presented to the wind at a greater angle than the one on the other side, the wing with the greater angle descended, and the machine turned in a direction just the reverse of what we were led to expect when flying the machine as a kite. The larger angle gave more resistance to forward motion, and reduced the speed of the wing on that side.

They discuss the uncertainty of calculations, made by the French Academy, then the Aeronautical Society of Great Britain, then Samuel Pierpont Langley, for the force of 1 mile/hour wind striking a plane of 1 square foot—if this is not settled, how much greater a problem when angle is also considered? or the shape of the surface? They took their own measurements and got strange results.

Propellers and first flight

In September–October 1902 they made 1000+ glides, some of which went high and far. They turned to propellers, necessary to sustain flight. At first they thought: "screw propellers are simply wings traveling in a spiral course." But these, too, proved complicated. But from their calculations they produced propellers giving 66% useful work to power used—"about one third more than had been secured by Maxim or Langley". So:

The first flights with the power-machine were made on the 17th of December, 1903. Only five persons besides ourselves were present. These were Messrs. John T. Daniels, W. S. Dough, and A. D. Etheridge of the Kill Devil Life Saving Station; Mr. W. C. Brinkley of Manteo, and Mr. John Ward of Naghead. Although a general invitation had been extended to the people living within five or six miles, not many were willing to face the rigors of a cold December wind in order to see, as they no doubt thought, another flying machine not fly. The first flight lasted only twelve seconds, a flight very modest compared with that of birds, but it was, nevertheless, the first in the history of the world in which a machine carrying a man had raised itself by its own power into the air in free flight, had sailed forward on a level course without reduction of speed, and had finally landed without being wrecked. The second and third flights were a little longer, and the fourth lasted fifty-nine seconds, covering a distance of 852 feet over the ground against a twenty-mile wind.

Only a few minutes later after the aircraft was returned to camp, a gust of wind blew it over, damaging it so greatly that experiments could not continue.

Subsequent flights

In spring 1904 they continued experiments, at Huffman Prairie, with a heavier machine. Fifty people including press attended their next exhibition. Wind was low, the machine didn't fly, and people were disappointed. The same thing happened the next day.

They still encountered problems with stability, including unexpected motions when turning. "The causes of these troubles—too technical for explanation here—were not entirely overcome till the end of September 1905."

They spent 1906 and 1907 "in constructing new machines and in business negotiations" then returned to Kill Devil Hill in May 1908 to demonstrate their ability to fulfill a contract with the U.S. Government for a 125-mile flight at 40 mph. All work thus far has been conducted at their own expense.

Original title	The Wright Brothers' aëroplane
Simple title	The Wright Brothers' aeroplane
Authors	Wright Brothers
Date	1908
Countries	FR
Languages	fr
Keywords	Wright Brothers, airplane, wing warping, Otto Lilienthal, Octave Chanute, Samuel Pierpont Langley, propeller, frame, stability, Signal Corps Specification Number 486
Journal	Century Mag.
Related to aircraft?	1
Page count	10
Word count
Wikidata id

Sources

• Brockett 1910, page 903, entry 13035: Wright, Wilbur, and Orville. The Wright Brothers' aeroplane. Century Mag., Vol. 76, No. 5 (Sept. 1908), New York, pp. 641-650, ill. 10. S (13035
• Scan at HathiTrust
• Scan at Library of Congress (p. 1)