Becoming Scientists

Heartened by successful trials with their model glider, the Wright brothers spent the year between the summer of 1899 and the summer of 1900 building a full-size glider designed for manned flight. The Wright brothers used the research and experimentation of the people who preceded them, but also introduced a number of their own innovations. In addition to designing wings that could "warp" (or twist like Wilbur Wright's box), they also moved the high point of the arc in the wings toward the front edge of the wings and mounted an elevator (a movable horizontal surface) to the front of the glider to help counteract upward or downward pitching. They went to Kitty Hawk, North Carolina, to test their full-size glider because the area had steady winds, wide open spaces, and sandy landing surfaces. They tested the glider a number of times as a kite, and then flew the glider a few times. By the time their stay in Kitty Hawk in the summer of 1900 was complete, the Wright brothers were pleased to learn that many of their designs, including the warping wings, the arc, and the elevator, worked well. The glider did not achieve as much lift as they hoped it would, but it had at least flown three hundred feet.

The amount of lift the aircraft generated seemed to be the only problem. So, based on tables that Otto Lilienthal had created for predicting how much lift a wing would generate, the Wright brothers increased the size and curvature of their wings. They had high expectations for their return to Kitty Hawk in 1901. The results, however, were disappointing; the new glider not only had problems with lift but also problems with its controls—both the elevator and the wing warping. The Wright brothers reduced the arc of the wings, which helped somewhat, but the glider still crashed and Wilbur was thrown into its elevator mechanism, receiving a black eye and bruises. After that, the brothers only flew their glider as a kite. The brothers were baffled by these results, and on the train ride home to Dayton, Ohio, a dejected Wilbur said that he did not think that people would learn to fly in his lifetime—perhaps not even in a thousand years.

When the brothers arrived home there was a letter waiting for them from Octave Chanute, a civil engineer, inviting them to come to Chicago to speak to the Western Society of Engineers. This was an intimidating request; the Wrights had done one thing that no one else had—compared actual flight data with Lilienthal's experimental data—but their flight data did not match the experimental data, and they were not sure why. What would they say to a body of learned scientists?

Just before Wilbur left to give his speech to the society, he and Orville built a wind tunnel out of a soap box and ran some preliminary experiments that convinced them that Lilienthal's tables were wrong. Wilbur gave his talk, which was received well, and upon returning to Dayton he and Orville made a fundamental change in their approach to harnessing lift: they transformed from practitioners (well-read enthusiasts who were trying to build a flying machine) into scientists (systematic empiricists who were trying to understand fundamental principles for harnessing lift). Throughout the winter of 1901–2 they created a better wind tunnel, built as many as two hundred different model wing shapes to test, measured lift and drag more accurately, and ran experiments using these measurements. Based on their experiments they were able to create more accurate tables and equations and designed a glider based on these. As a result, in the summer of 1902 their new glider responded well to its controls, flew over seven hundred times and sometimes for over six hundred feet, allowed them to land safely, and enabled them to develop the most advanced piloting skills in the world. By transforming themselves from practitioners to scientists, they built a fully controllable aircraft.