7 The 100 Most Influential Inventors of All Time 7This 1902 photo depicts Wilbur Wright fl ying the glider biplane he designed
with the help of his brother Orville. Getty/Hulton Archive
intervened to change altitude or direction. As experienced
cyclists, the Wrights preferred to place complete con-
trol of their machine in the hands of the operator.
Moreover, aware of the dangers of weight-shifting control
(a means of controlling the aircraft by shifting the posi-
tion of the pilot), the brothers were determined to
control their machine through a precise manipulation
of the centre of pressure on the wings. After consider-
ing various mechanical schemes for obtaining such
control, they decided to try to induce a helical twist
across the wings in either direction. The resulting
increase in lift on one side and decrease on the other
would enable the pilot to raise or lower either wing tip
at will.