İbrahim Can Bakır
Wilbur and Orville Wright were well-known brothers who were inventors of airplane concept. Wilbur Wright was born in 1867 and his brother Orville was born in 1871 in Ohio, Dayton. Wilbur was the successful student and he had a chance to go Yale University but he had an unfortunate accident when he was playing ice-hockey. After this accident, he felt into depression and he didn’t want to go university, and he even didn’t graduate from high school. The brothers firstly worked in newspaper. Orville was a publisher and Wilbur was an editor in West Side News. In 1892, they opened a bicycle shop and started to produce and repair bicycles. After a few years, they had their own in bicycle brand “Wright Cycle”. 
Even when they were working in bicycle business, they always had the same passion and interest in aviation. They read lots of books and papers about it and they started to work on aeronautical problems. In 1899, Wilbur Wright wrote a letter to Smithson Institution and mentioned about their interests in aeronautical concepts and requested for some researches made in past. 
At those days, the pioneers of aviation had researches especially about these two topics which were powered aircrafts and gliders. As a beginning, Wright Brothers tended to work on non-carrying gliders. Because understanding of basics of flying can help them to make complex things. Before they start to work on their gliders, they focused on the studies made in past. One of the people who Wright Brothers regarded his study as an important was Sir George Couley (1773-1857). He was the first who used scientific methods in aviation. He made aerodynamic tests on full-size gliders. Also an another important person was Otto Lilienthal. He found most complete data about aeronautical concept so far. After observations on past researchers, Wrights had three topics to study, which were, lifting surface and wings, balance and controlling of gliders, and propulsions. 
Firstly, they tried to handle balance and controlling problem. In the beginning, they thought to use gear system to control wings. But they gave up because it can make glider too heavy. Wilbur inspired from twist boxes and tried to apply same idea to control wings’ angles. After they made some calculations about wings, they decided to produce a glider which has front wing take oncoming flows with a bigger angle than the angle of rear wing. They thought the gliders can be controlled easily when they are lifted. This method was called as “wing-warping”.
Figure1: Wing Warping 
After they decided about the position of wings, they focused on lifting. In the previous examinations, Otto Lilienthal used the technique which was to keep center of pressure stable. He suggested changing of pilot weight can keep center of pressure stable. But it cannot be applied to big-size heavy planes. According to their experience about bicycle, Wrights knew bicycles...