Otto Lilienthal after whom is named Berlin's busiest airport - Berlin Tegel "Otto Lilienthal" Airport, is the most significant aeronautical pioneer. Of all the men who attacked the flying problem in the 19th century, Wilbur Wright stated that Otto Lilienthal was the most important. Hundreds of years before Otto’s glides, many people such as Cayley, Spencer, Wenham, Mouillard, etc. made feeble attempts at gliding, however, their failures were so complete that nothing of value resulted.
Lilienthal began to conduct studies of the forces operating on wings in a stream of air in the late 1870s. Having explored the physical principles governing winged flight, Lilienthal began to design and build gliders on the basis of the information he had gathered. Over 2,000 flights in at least 16 distinct glider types were made and recorded by Lilienthal from 1891 to 1896. Images of Lilienthal flying through the air aboard his standard glider at that time appearing in scientific and popular publications convinced millions of readers worldwide that unpowered human flight was possible, total control of an aerial device while aloft was within reach.
During his short flying career, Lilienthal developed a dozen models of monoplanes, wing flapping aircraft and two biplanes. Beyond his technical contributions, he sparked aeronautical advancement from a psychological point of view, as well by unquestionably demonstrating that gliding flight was possible. He was a great inspiration to the Wright brothers, in particular- They adopted his approach of glider experimentation, used his aerodynamic data as a starting point in their own research, invented and flew the world’s first successful aeroplane in 1903.
Lilienthal built a conical hill called Fliegeberg (about 45 feet high and about 200 feet in diameter) in 1894 near Berlin, Germany, at Gross-Lichterfelde. It allowed him to launch his gliders into the wind no matter which direction it was coming from.
During a flight on 9th August 1896, Otto Lilienthal's glider collapsed and he suffered severe injuries. His death, the following day at a hospital in Berlin, was considered a distinct blow to progress in the aerial arts. In 1932, the Fliegeberg was redesigned as a memorial to Lilienthal.
Lilienthal's efforts broke the 'respectability barrier' that haunted serious efforts to develop aeroplanes. Lilienthal is the source of two famous quotes about inventing aircraft. The first illustrates the discipline that must accompany creativity in invention: "To invent an airplane is nothing. To build one is something. But to fly is everything." The second was all too prophetic: "Sacrifices must be made."