Sir George Caley, Otto Lilienthal, Samuel Pierpont Langley, and the Wright Brothers all used UAS in the development of their concepts for manned aircraft. In what ways did they use UAS and why do you think they did so?

All the innovators mentioned in the question statement used UAS as a facility to keep the aircraft lightweight and manageable. They used UAS because flying a machine while sitting in it was initially considered dangerous.

Explanation:

In the initial phase of the development of aviation technology, the progress on the safety of the aircraft during the flight was slow and it was deemed risky to fly the aircraft with a human sitting inside the aircraft controlling it. Extensive use of UAS was also made to make the aircrafts fit for military use. Moreover, all the measures to keep the aircraft light were implemented to increase the efficiency of the aircraft.