Sir George Cayley
Sir George Cayley was a prolific English engineer and is one of the most important people in the history of aeronautics. In 1799 he set forth the concept of the modern aeroplane as a fixed-wing flying machine with separate systems for lift, propulsion, and control.
He was a pioneer of aeronautical engineering and is sometimes referred to as “the father of aviation.” Designer of the first glider to carry a human being aloft, he discovered and identified the four aerodynamic forces of flight, which act on any flying vehicle: weight, lift, drag and thrust. Modern aeroplane design is based on those discoveries, and also on the importance of cambered wings, also identified by Cayley. With the design and construction of his first working glider, Otto Lilienthal (1848-1896) bestowed a sense of viability and respectability on the young science of aviation. Lilienthal modeled his flying craft after birds and butterflies and constructed the prototypes from wax, cloth, wire, and willow rods.
A typical Lilienthal glider design was comprised of 13 square meters of mono-wing surface. Through his studies of birds, he became intent on replicating the flight motions of the seagull, because of its extremely broad wing strokes and its ability to sail on the sea breeze. Also intriguing to Lilienthal was the stork. He said that it “seems to have been created for the purpose of serving as a model for human flight.”
Lilienthal’s goal in his experiments was to comprehend the forces and motions involved in flight. He not only could fly but also could recreate his flights repeatedly with the same apparatus. This display of control was a clear indication that he was not just falling from the air but actually guiding the movement of the aircraft.
Lilienthal flew more than 2,500 flights and achieved a maximum flight distance of approximately 350.75 meters. He designed 18 different gliders, including 15 monoplanes and three biplanes. All were controlled by weight distribution of the passenger.
Thereafter gliders were built by pioneers such as Jean Marie Le Bris, Percy Pilcher, Octave Chanute and Augustus Moore Herring to develop aviation.