Bigeo, Flying Vehicle in Joseon Dynasty

'Bigeo' is a flying vehicle which is known to be produced by Jeong Pyeonggu in 1590s and can fly the sky like airplanes. The vehicle, which is recorded in ancient documents, is 300 years ahead of western countries who started developing airplanes in early 20 centuries. Bigeo had a large leather bag at the center of the body filled with compressed air, and when a cap under the bag was opened, can fly upward by the reactive force of the compressed air ejected through the hole.