OVERVIEW

Much of the theoretical and empirical foundations of unmanned as well as manned aeronautics were laid in Europe during the nineteenth century. Translations from German of Otto Lilienthal's work in the 1880s and 1890s inspired the Wright brothers, who were also introduced to the earlier work of Henson and Stringfellow in England through the French-American Octave Chanute, who maintained a correspondence with several European aviation pioneers. It is fair to recognize that the Wrights' accomplishment of 1903 owed much to the successes and failures of their European predecessors. Wilbur Wright's tour of Europe in 1908, which demonstrated the performance of the Wright Flyer across the continent, also spurred a flurry of indigenous imitators, many of whom became the first native aviators in their countries.

In attempting to get themselves into the air, almost every early pioneer of aviation first built and flew or tried to fly a precursor model of their proposed man-carrying design. In this way, the development of the unmanned airplane occurred simultaneously with that of the manned airplane. The lessons learned in aerodynamic stability by conducting early unmanned flight, unpowered and powered, were applied directly to the betterment of manned flight attempts. From Cayley's 1804 model glider to Du Temple's clockwork-powered 1857 model and Langley's 1896 steam- powered model, unmanned flight forerunners often succeeded where their follow-on manned flight attempts did not. It is interesting to note that in recent decades, in a reversal of history, early flights of new UAV designs have occasionally employed a human pilot...