On December 17, 1903, Wilbur and Orville Wright became the first to make a controlled and sustained flight in a power-driven, heavier-than-air craft. Though not formally trained in the field of engineering, the brothers approached the problem of flight as would any well-trained engineer. Using a thorough and systematic approach, they were able to solve three key challenges that kept all other would-be flyers aground. First, there was the issue of lift. When the brothers found the existing data on lift inaccurate, they collected their own data, making use of a wind tunnel that they designed and built themselves. Then there was the control of an aircraft. While others saw their crafts as being inherently stable, the Wrights knew that the opposite was true; they knew that a successful aircraft would have to continually make adjustments in response to changes in wind speed and direction. Finally, there was propulsion. Before the Wrights, there was no detailed data on propeller design. Again with the help of their wind tunnel, they developed a propeller that was far more efficient than any other then in existence. In fact, their propeller design has remained virtually unchanged to this day. This interactive feature describes the Wrights’ 1903 Flyer, including how they used the plane’s controls to manoeuvre their craft.