Although fixed-wing aircraft receive all the attention by most historians, helicopter flight was the first flight envisioned by man. In fact, the ancient Chinese were .
Military Documentary – Helicopters full documentary HD National Geographic 2017 national geographic,documentary,national geographic documentary .
History Channel – History of Helicopters Helicopter Invention – Discovery History Documentary history,history documentary,history channel,discovery,discovery .
History of Helicopters: Aircraft type – Science Channel Documentary 2017.