The American aviation pioneers Wilbur (1867-1912) and Orville (1871-1948) Wright were the first to accomplish manned, powered flight in a heavier-than-air machine.

Wilbur and Orville Wright were the sons of Milton Wright, a bishop of the United Brethren in Christ. Wilbur was born on April 16, 1867, in Millville, Ind.; Orville was born on Aug. 19, 1871, at Dayton, Ohio. Until the death of Wilbur in 1912, the two were inseparable. Their personalities were perfectly complementary: Orville was full of ideas and enthusiasms, an impetuous dreamer, while Wilbur was more steady in his habits, more mature in his judgments, and more likely to see a project through.

In their early years the two boys helped their father, who edited an evangelical journal called the Religious Telescope. Later, they began a paper of their own, West Side News. In 1892 they opened the Wright Cycle Shop in Dayton, which was the perfect occupation for the Wright brothers, involving one of the exciting mechanical devices of the time: the bicycle. When the brothers took up the problems of flight, they had a solid grounding in practical mechanics.

The exploits of one of the great glider pilots of the late 19th century, Otto Lilienthal, had attracted the attention of the Wright brothers as early as 1891, but it was not until the death of this famous aeronautical engineer in 1896 that the two became interested in gliding experiments. They then resolved to educate themselves systematically in the theory and state of the art of flying.

The Wrights took up the problem of flight at an auspicious time, for some of the fundamental theories of aerodynamics were already known; a body of experimental data existed; and most importantly, the recent development of the internal combustion engine made available a sufficient source of power for manned flight. Although they sometimes acted as scientists, the basic approach of the Wrights was that of the engineer. They had no formal training as either scientist or engineer, but they combined the instincts of both. They began by accumulating and mastering all the pertinent information on the subject, designed and tested their own models and gliders, built their own engine, and, when the experimental data they had inherited appeared to be inadequate or erroneous, they conducted new and more thorough experiments.

Armed with this information, the Wright brothers proceeded to fly double-winged kites and gliders in order to gain experience and to test data. After consulting the U.S. Weather Bureau, they chose an area of sand dunes near the small town of Kitty Hawk, N.C., as the site of their experiments. In September 1900 they set up camp there and began the work that culminated three years later in success.

Their first device failed to fly as a kite because it was unable to develop sufficient lift. Instead, they flew it as a free glider and learned a great deal from their experience, partly because of the careful records they kept of their failures as well as of their successes. Their own data showed conclusively that previous tables of information were greatly inaccurate.

Returning to Dayton in 1901, the Wright brothers built a wind tunnel, the first in the United States, and here they tested over 200 models of wing surfaces in order to measure lift and drag factors and to discover the most suitable design. They also discovered that although screw propellers had been used on ships for more than half a century, there was no reliable body of data on the subject and no theory that would allow them to design the proper propellers for their airship. They had to work the problem out for themselves, mathematically.

The Wrights, by this time, not only had mastered the existing body of aeronautical science but also had added to it. They now built their third glider, incorporating their findings, and in the fall of 1902 they returned to Kitty Hawk. They made over 1,000 gliding flights and were able to confirm their previous data and to demonstrate their ability to control the three axes of motion of the glider. Having learned to build and to control an adequate air frame, they now determined to apply power to their machine.

The Wright brothers soon discovered, however, that no manufacturer would undertake to build an engine that would meet their specifications, so they had to build their own. They produced one that had four cylinders and developed 12 horsepower. When it was installed in the air frame, the entire machine weighed just 750 pounds and proved to be capable of traveling 31 miles per hour. They took this new airplane to Kitty Hawk in the fall of 1903 and on December 17 made the world's first manned, powered flight in a heavier-than-air craft.

The first flight was made by Orville and lasted only 12 seconds, during which the airplane flew 120 feet. That same day, however, on its fourth flight, with Wilbur at the controls, the plane stayed in the air for 59 seconds and traveled 852 feet. Then a gust of wind severely damaged the craft, and the brothers returned to Dayton convinced of their success and determined to build another machine. In 1905 they abandoned their other activities and concentrated on the development of aviation. On May 22, 1906, they received a patent for their flying machine.

The brothers looked to the Federal government for encouragement in their venture, and gradually interest was aroused in Washington. In 1907 bids were asked for an airplane that would meet government requirements--22 bids were received, three were accepted, but only the Wright brothers finished their contract. They continued their experiments at Kitty Hawk, and in September 1908, while Wilbur was in France attempting to interest foreign backers in their machine, Orville successfully demonstrated their contract airplane. It was accepted by the government, although the event was marred by a crash a week later in which Orville was injured and a passenger was killed.

Wilbur's trip to France proved to be a success also, and in 1909 the Wright brothers formed the American Wright Company, with Wilbur taking the lead in setting up and directing the business. His death in Dayton on May 30, 1912, left Orville in a state of desolate isolation. In 1915 he sold his rights to the firm and gave up his interest in manufacturing in order to turn to experimental work. He had little taste for the bustle of commercial life.

After his retirement, Orville lived quietly in Dayton, conducting experiments on mechanical problems of interest to him, none of which proved to be of major importance. His chief public activity was service on the National Advisory Committee for Aeronautics (the predecessor agency of NASA), of which he was a member from its organization by President Woodrow Wilson in 1915 until his death in Dayton on Jan. 30, 1948.

Further Reading

• The letters and papers of the Wright brothers are available in Fred C. Kelly, ed., Miracle at Kitty Hawk: The Letters of Wilbur and Orville Wright (1951), and Marvin W. McFarland, ed., The Papers of Wilbur and Orville Wright (2 vols., 1953). Fred C. Kelly, The Wright Brothers (1943), is a biography authorized by Orville Wright. Other recommended studies are Elsbeth E. Freudenthal, Flight into History: The Wright Brothers and the Air Age (1949), and, for young people, Quentin J. Reynolds, The Wright Brothers: Pioneers of American Aviation (1950).