The Airplane: How Does it Work?

            
             Since ancient times, people have always dreamed to fly.
             The history of human flight began with adventurous people equipped with .
             flapping wings who flung themselves from high places. However, these devices did not .
             perform well. According to Donald Lopez, Senior Advisor to the director of the National Air .
             and Space Museum, in his book Aviation a Smithsonian guide, people of that time tried to .
             imitate birds. For example "in 1010 a monk named Eilmer jumped from Malmesbury Abbey .
             in England and broke his legs. In 1162, a man in Constantinople fashioned sail-like wings .
             from a fabric gathered into pleats and folds. He plummeted from the top of a tower and died. .
             In 1536, Denis Bolori in France tried to fly using wings flapped by a spring mechanism. He .
             fell to his death when the spring broke."" (Lopez, Aviation a Smithsonian guide, 1995, p 16).
             From this idea, the main concept of airplane comes from Greek culture that related .
             the principle of flying to birds. Birds have two wings that help them maintain their balance .
             while flying. In addition, by flapping their wings, they can fly and reach high places. Airplane .
             has the same concept. All airplanes have two wings that play the same role as the bird's .
             wings, but not by flapping them. After many centuries, inventors had developed the idea of .
             flying. The first man who thought of that was Leonardo da Vinci. Da vinci grasped a .
             better understanding of flight than many experimenters did in centuries before. In the 1800s, .
             George Cayley, an aeronautic engineer, went very far by constructing the first glider. After .
             that, the Wright brothers arrived with triumph. They were the first inventors who succeeded in .
             building the first airplane. .
             Later, the innovation of airplane changed the world. The transportation of cargos .
             started to become more frequent. The time of traveling had been reduced. Moreover, .
             airplanes had been used also for military purposes. After that, inventors and scientists had .