Bensen B 9

The Bensen B-9 Little Zipster was a small helicopter developed by Igor Bensen in the United States in the 1950s and marketed for home building. Similar in general configuration to Bensen's previous rotor kite and autogyro designs, it consisted of an open aluminum framework but substituted the autorotating main rotor for a coaxial, counter-rotating system of two, two-bladed rotors. A large tailfin provided directional stability, and the aircraft was controlled by a handlebar system extending over the pilot's head to the rotor hub.