For centuries man has watched with envy the easy flight of birds and has tried to simulate their basic form, structural principles and methods of control. Often too much enthusiasm and too little technical knowledge has ended in disaster, and the most successful people were those who relied upon models for their initial data.

The Wright Brothers were among the first to apply an engineering approach to the problems concerning the magnitude of loads occurring on wing and control surfaces. To this end they constructed a wind tunnel as long ago as 1901 and succeeded in measuring actual forces on model aeroplanes, and in comparing them with systematic glider experiments. They continued to develop their research along these lines to achieve the first power flight in December 1903.