New Delhi: The first form of man-made flying objects were kites.Later the invention of hydrogen led to the invention of hydrogen balloons in the 18th century. In the 19th century experiments with gliders provided the
2. The Hiller X-18
This plane was the testing ground for tilt-wing and vertical takeoff and landing planes.
It was conceived in 1955 and had its first flight in 1959. The plane had 20 successful flights.