High glide on Oct. 10, 1902. Courtesy, Smithsonian Institution.
While lying awake one night, Orville thought of converting their vertical tail from two fixed vanes to a single movable rudder. When making a turn or recovering lateral balance, this rudder could be moved toward the low wing to compensate for the increased drag imparted to the high wing by its greater angle of attack. Wilbur listened attentively when Orville told him about the idea the next morning. Then, without hesitation, Wilbur not only agreed to the change but immediately proposed the further important modification of interconnecting the rudder control wires with those of the wing-warping. Thus by a single movement the operator could affect both controls. Through the brilliant interplay of two inventive minds, all the essentials of the Wright control system were completed within a few hours.
The combination of warp and rudder control became the key to successful control of their powered machine and to the control of all aircraft since. (Modern airplanes—and indeed Wright planes after the middle of their 1905 experimental season—do not have the aileron and rudder controls permanently interconnected, but these controls can be and are operated in combination when necessary.) Together with the use of the forward elevator, it allowed the Wrights to perform all the basic aerial maneuvers that were necessary for controlled flight. The essential problem of how to control a flying machine about all three axes was now solved.
The trials of the 1902 glider were successful beyond expectation. Nearly 1,000 glider flights were made by the Wrights from Kill Devil, West, and Little Hills. A number of their glides were of more than 600 feet, and a few of them were against a 36-mile-an-hour wind. Flying in winds so strong required great skill on the part of the operator. No previous experimenter had ever dared to try gliding in so stiff a wind. Orville wrote his sister, “We now hold all the records! The largest machine we handled in any kind [of weather, made the longest dis]tance glide (American), the longest time in the air, the smallest angle of descent, and the highest wind!!!” Their record glide for distance was 622½ feet in 26 seconds. Their record glide for angle was an angle of 5° for a glide of 156 feet. The 1902 glider had about twice the dynamic efficiency of any other glider ever built up to that time anywhere in the world.
By the end of the 1902 season of experiments, the Wrights had solved two of the major problems: how properly to design wings and control surfaces and how to control a flying machine about its three axes. Most of the battle was now won. There remained only the major problem of adding the engine and propellers. Before leaving camp, the brothers began designing a new and still larger machine to be powered with a motor.
It was the 1902 glider that the Wrights pictured and described in the drawings and specifications of their patent, which they applied for in March of the following year. Their patent was established, through the action of the courts in the United States and abroad, as the basic or pioneer airplane patent.
The Motor and the Propellers
Home again in Dayton, the Wrights were ready to carry out plans begun in camp at Kill Devil Hills for a powered machine. They invited bids for a gasoline engine which would develop 8 to 9 horsepower, weigh no more than 180 pounds or an average of 20 pounds per horsepower, and be free of vibrations. None of the manufacturers to whom they wrote was able to supply them with a motor light enough to meet these specifications. The Wrights therefore designed and built their own motor, with their mechanic, Charles E. Taylor, giving them enthusiastic help in the construction.
The Wright motor used in the first flights of Dec. 17, 1903, after its reconstruction in 1928.