Wilbur wrote his father:
I do not intend to take dangerous chances, both because I have no wish to get hurt and because a fall would stop my experimenting, which I would not like at all. The man who wishes to keep at the problem long enough to really learn anything positively must not take dangerous risks. Carelessness and overconfidence are usually more dangerous than deliberately accepted risks.
The problem of equilibrium was the second major problem that the brothers had to solve. They needed to devise measures to steer or control a flying machine both up and down and to each side.
When the Wrights started their investigations they believed that others had already solved the problems of how to design wings, propellers, and motors. Only later did they realize that they must also correctly design both the wings and the propellers and build their own motor. Thus their third major problem became how to design wings sufficiently strong to support the weight of the machine, motor, and pilot to take the greatest advantage of air particles providing lift by streaming along the upper and lower surfaces of the wings.
A fourth major problem that faced Wilbur and Orville was how to design a light-weight, high-powered engine and the propellers required to drive the machine through the air. They were to find that these problems were interrelated and that they would solve them only after 4½ years of spare-time study and experimentation.
First Experiments, 1899
Wilbur and Orville realized that the motion of the air on a flying machine is frequently variable and tricky, causing the machine to rear up or down, or one wing to rise higher than the other, and the machine to become unstable. The problem—how to control a flying machine—was to find a method of restoring the machine’s equilibrium both up and down and to each side.
Most pre-Wright experimenters had relied on human control to balance flying machines. The operator simply shifted the weight of his body to tilt the wings in the direction opposite from adverse action of the wind. But the continual contortions and acrobatics required to maintain equilibrium by this method were not within the skill of many experimenters. While using it, both Lilienthal and Percy S. Pilcher, an English experimenter, were killed in nose dives.
Chanute sought to effect “automatic stability” independent of the operator by causing the flying machine’s structurally automatic supporting surfaces to adjust positions by flexible joints automatically with changes in the wind. Wilbur and Orville were to conceive a different method of control than that sought by Chanute, though they themselves later designed and patented an “automatic” device—a pendulum analogous to Sperry’s gyroscope.
