For the next two years, Will and Orville used their
bike shop as an invention center. Using a bike as their first testing device, they performed airfoil experiments. Pedaling
their contraption as fast as they could was exhausting, so the brothers invented a
wind tunnel into which they placed two homemade devices - one to test
lift and the other to test drag. The blower fan, which was driven by an overhead belt, created winds up to 35 miles per hour.
Writing down all their observations on strips of wallpaper, they ultimately compiled
their findings into a notebook. Among other important conclusions, the brothers determined the commonly accepted coefficient of lift was too high. They also found a wing produced more lift if it had the shape of a parabola.
Using the data from all their experiments, the brothers built a reworked glider in 1902. It was the first aircraft that solved the fundamental problems of flight:
lift and
three-axis control (referred to as pitch, roll, and yaw).