It is a prerequisite of advanced flight.
Sustained, self-powered motion through the air, or Flight, has tantalized humans since the dawn of time. Despite many experiments and attempts at flying, it wasn't until the development of the internal Combustion engine that the laws of Physics could be made to work for man's quest. Just after the turn of the 20th Century, Orville and Wilbur Wright made the first four controlled, sustained flights at Kitty Hawk, N.C. The technology of Flight advanced rapidly. Within a relatively few years, aircraft were circling the globe, safely delivering passengers and mail at record speeds.