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In Spain, the Marquis Pateras Pescara built several complex helicopters of the coaxial type and which flew

In Spain, the Marquis Pateras Pescara built several complex helicopters of the coaxial type and which flew. Pescara held a large number of patents, including one on autorotation, and the foresight to attempt blade pitch control and a means of tilting the rotor axis for horizontal flight.

Credits - Hiller Aviation Museum