Devoir de Philosophie

Orville Wright.

Publié le 10/05/2013

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Orville Wright. Orville Wright (1871-1948), American aeronautical engineer famous for his role in the first controlled, powered flight in a heavier-than-air machine and for his participation in the design of the aircraft's control system. Wright worked closely with his brother, Wilbur Wright, in designing and flying the Wright airplanes. See Airplane. Orville Wright was born in Dayton, Ohio. He and Wilbur attended high school in Dayton, but neither boy formally graduated from high school. While in high school the brothers developed an interest in mechanical things, taught themselves mathematics, and read as much as they could about current developments in engineering. They also made some attempts at editing and printing small local newspapers. In 1892 the brothers formed the Wright Cycle Company; for the next ten years they designed, built, and sold bicycles. The exploits of Otto Lilienthal, the German pioneer of gliders, inspired the Wrights to begin exploring the possibilities of powered flight in the 1890s. Lilienthal's death in an 1896 glider crash convinced the brothers that they not only must build successful airplanes, but must also learn to fly them correctly. During the next few years, they focused on controlling the direction and stability of an airborne object. In August 1899 they flew a kite with a wingspan of about 1.5 m (about 4.9 ft) and with controls for warping (twisting) the wings to control direction and stability. Their wing-warping method was the forerunner of the later idea of ailerons, flaps that can move independently of airplane wings to steer and stabilize the airplane (see Airplane: Control Components). In 1900 the Wrights built a larger kite with a 5-m (17-ft) wingspan that could carry a pilot. They chose to test their craft near Kitty Hawk, North Carolina, because the site had suitable steady winds and sandy banks, which would minimize the impact of the craft and pilot upon landing. The kite flew well and Wilbur achieved a few seconds of piloted flight. The following July they returned to Kitty Hawk and built a wooden winged sled at Kill Devil Hills, where there were large sand dunes. Their new machine was longer and had a different wing shape than the previous model. It also had a hand-operated elevator attached to the horizontal tail stabilizer. Again they achieved encouraging results, particularly after further alterations to the wing arch, but there were still problems with stability and control. During the following winter Orville Wright designed and built a small wind tunnel and tested various wing designs and arches. In the course of these tests the Wrights compiled the first accurate tables of lift and drag, the important parameters that govern flight and stability. By winter's end the brothers had built a new glider that had a 10-m (32-ft) wingspan and had, at first, a double vertical fin mounted behind the wings. Turning was still difficult, however, and they converted the fin to a single movable rudder operated by the wing-warping controls. This configuration proved so successful that they decided to attempt powered flight the following summer. During the winter of 1902 they searched in vain for a suitable engine for their craft and for information about propeller design. They eventually constructed their own 8.9-kilowatt (12-horsepower) motor and made their own efficient propeller. After some initial trouble with the propeller shafts, the so-called Wright biplane took to the air and made a successful flight on December 17, 1903, at Kill Devil Hills near Kitty Hawk. The airplane had a wingspan of 12 m (39 ft) and weighed 340 kg (750 lb), including the pilot. The two brothers took turns flying the plane. Orville made the first successful flight, which lasted 12 seconds. The following year the Wrights incorporated a 12-kilowatt (16-horsepower) engine and separated the wing-warping controls from the rudder controls. They flew this new aircraft at their home town of Dayton, learning to make longer flights and tighter turns. In 1905 the Wrights had enough confidence in their design to offer it to the United States War Department. The following year they patented their control system of elevator, rudder, and wing-warping. Although they spent time patenting and finding markets for their machines during the next few years, they did not exhibit them publicly until 1908. That year Orville demonstrated the airplanes in the United States, setting several records when he kept the plane aloft for more than an hour on September 9. In 1909 the Wrights demonstrated their airplanes in Europe. The United States and European governments put in many orders for Wright airplanes, and the Wrights needed a manufacturing plant. In 1909 they formed the Wright Company to manufacture their airplanes. Orville became president of the Wright Company after Wilbur's death in 1912, but in 1915 he sold his interest in the company to pursue aviation research. He eventually became a member of the National Advisory Committee on Aeronautics. By the time of his death Wright had received many awards and honors for the momentous achievement of the Wright brothers. Microsoft ® Encarta ® 2009. © 1993-2008 Microsoft Corporation. All rights reserved.

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