By 1892 the two brothers opened a business selling and repairing bicycles, which were very popular at the time. Later, they began manufacturing their own brand of bicycles. The money they made helped them to fund their interest in flying. In 1896 three important aeronautical events took place. Samuel Langley of the Smithsonian Institute flew an unmanned, steam-powered model aircraft in May. Octave Chanute successfully tested several gliders along Lake Michigan during the summer. In August, another glider pilot, Otto Lilienthal, was killed when his glider plunged to the ground. In May of 1899, Wilbur wrote to the Smithsonian to request information on aeronautics. Combining the discoveries of Chanute, Lilienthal, Leonardo da Vinci, Langley, and Sir George Cayley, they began to experiment.
Even though the Wright brothers always spoke of their teamwork and shared the credit for the work they did, Wilbur was the driving force behind everything. They decided to follow in Lilienthal's path, even though it had ended badly for Lilienthal. The brothers knew they had to master gliding before they could attempt a flight driven by a motor. When yet another, Percy Pilcher, died trying to fly, they only felt more strongly that in order to have a successful, safe flight, they needed a reliable method for the pilot to control it.
The Wright brothers began studying birds. They noticed that the tips of the feathers would angle to change the path the bird took. The brothers decided this might be a good method for their flying machine as well. They also hoped this would help the machine recover when the wind tilted it to one side or the other. One day, while Wilbur idly twisted a long box made to hold inner tubes at their bicycle shop, they discovered wing warping.
The Wright brothers gave up inherent stability and went for absolute pilot control instead. They tested their theory with a large box kite in the shape of a biplane. Wing warping was controlled by four lines attached to the kite. In 1900 the brothers went to Kitty Hawk, North Carolina to begin their gliding experiments with a pilot on board. In a few days, the brothers tested out their theories. The design of the glider worked well, although the lift was not as much as they had hoped for. They eventually figured out that the pilot should best lie on the lower wing.
Orville and Wilbur returned to the drawing board, experimenting with wing shapes on a bicycle, then building a six-foot wind tunnel so they could test miniature wings. They tested 200 different wings, performing detailed tests on 38 of them. They discovered a fact that would benefit the aeronautic industry in the future: longer, narrower wings give a better lift-to-drag ratio than broad wings. The 1902 glider and its new rudder worked so well to prevent adverse yaw that it created a new problem – instead of coming out of a turn, sometimes it would continue to form a tighter turn, a problem that is called a ground loop today. They discovered that by making the rudder movable and turning it opposite to the wing warping, they had much better control of the flight. By October of 1902, they had true control when turning their glider. By 1903, they had their three axis-control designed. They applied for a patent on their flying machine with an added motor. The Wright brothers created a propeller that was very efficient for their time, and the engine they designed was a primitive fuel-injection system.
When they went public, there was a controversy over whether they had really done what they claimed. They worked in private, not in front of crowds like the other aeronautic pioneers. They began demonstrating their airplanes in the United States and Europe. Then a patent war was started with Glenn Curtiss, and it kept Wilbur busy until his death in 1912. The lawsuits damaged the Wright brothers' reputations, even though they eventually won. Orville sold the company in 1915 and spent his remaining years serving on various boards and committees on aeronautics.