A single-seater, the last of a family of experimental helicopters designed in Brazil by the engineer Paul BaumgartI. After the first model with coaxial rotors, it was given a traditional two-blade articulated rotor.
G.Apostolo "The Illustrated Encyclopedia of Helicopters", 1984
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Paul Baumgarti was an Austrian who had worked on three helicopter designs during the war years before emigrating to Brazil. He experimented with a number of light helicopters in the 1950s and 1960s including the single-seat PB-60 unpowered ground-towed rotor kite, and the PB-64 which was an ultra-light single-seater with a minimal tubular fuselage structure. Baumgarti subsequently built his PB-63 under Brazilian Air Ministry funding. This was a conventional helicopter with a single seat and semi-enclosed cabin, powered by an 85hp Continental C.85 engine. No production of any of these designs was undertaken.
R.Simpson "Airlife's Helicopter and Rotorcraft", 1998