World War Airplanes, Wooden Propellers and Early Commercial Flight
Man has always dreamed of becoming air-born. From the earliest legends there have been stories of men strapping birdlike wings, stiffened cloaks or other devices to themselves and attempting to fly, typically by jumping off of a tower or cliff. For much of his life, Leonardo da Vinci was fascinated by the phenomenon of flight, producing many studies of the flight of birds, including his c. 1505 Codex on the Flight of Birds, as well as plans for several flying machines, a flapping ornithopter and a machine with a helical rotor.
By the first half of the 20th Century, the science of flight had come a long, long way.