Hiller UH-4 Commuter
The UH-4 was a development of the XH-44, which retained the co-axial contra-rotating two-bladed rotors, though the diameter was considerably increased. A two-seat all-metal helicopter with tricycle undercarriage, three were built. The prototype was registered N67706.
Engine: Lycoming O-290-0, 150hp
Rotor diameter: 10.08m
Max ceiling: 3660m
Cruising speed: 120km/h