Originating from the redesign of the R-5A (VS-317) developed in 1945. It was the first FAA certificated helicopter. The passenger capacity is upgraded to four. Other designations are H-5 (F, G, H) under the U.S. Air Force (which can be fitted with floats for Air Sea Rescue) and HO3S under the Navy. The S-51 is the commercial version.
See this at the American Helicopter Museum in West Chester, PA, USA.
VTOL type: Helicopter
Lift configuration: Single main rotor
Dedicated control device: Tail rotor
Crew required: 1-2
Crew seating: Tandem
Landing gear: Wheels (non-retractable)
Overall Height: 3.94 m (12.9 ft)
Overall Length: 17.39 m (57.0 ft)
Overall Width: 14.63 m (48.0 ft)
Max Gross Weight (ground): 2495 kg (5500 lb)
Max Range: 418 km (226 nm)