The Baumgärtl PB-64 was a 1950s single-seat helicopter designed and built by the Austrian-designer Paul Baumgärtl for the Brazilian Air Ministry.
[1] The PB-64 had an unusual rotor drive with two lightweight pulse jets mounted on the rotor, although not on the tips of the blades which was more normal.
[1] The engines were mounted at each end of a bar, at right-angles to the main rotor which also acted as a stabilizer bar.
[1] The main structure was a simple keel with a tricycle landing gear and an open seat for the pilot and a rudder on a simple tail boom.
[1] Data from [1] The Illustrated Encyclopedia of AircraftGeneral characteristics Performance