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American WWII's aircraft


Sikorsky R-4 / HNS-1

In the spring of 1941 a prototype helicopter designed by Igor Sikorsky was performing well enough to warrant a contract being awarded to the Vought-Sikorsky division of United Aircraft for the development of a two-seat version, designated the XR-4. XR-4 retained the single rotor of the VS-300 but had a covered fuselage, side-by-side seating and dual controls. The flying controls in the XR4 set the standard for all subsequent helicopters. The XR4 was re-engined in 1943 and called XR4C. Service trials with the YR-4A and YR-4B, including one from a tanker, resulted in the final variant, the R-4B.

The first flight of the new helicopter was made in January 1942, and 130 production examples were soon produced. The R-4 recorded two firsts: it accomplished the first helicopter landing aboard a ship, and the first rescue by a helicopter (April 23, 1944 in Burma - one YR-4 of new Air Commandos evacuated 4 persons from aircraft L-1, which crashed over Japan teritory - first helicopterīs combat engaging).

Twenty-five R-4s (under the designation HNS-1) were operated by the U.S. Navy and U.S. Coast Guard, and 52 R-4s were operated by the British (under the designation Hoverfly I). This aircraft was the first helicopter produced for the US Air Force, and the world's first mass-produced helicopter. Four (probably) prototypes used Air Commandos in Burma.

General characteristics
Primary function Two-seat training and rescue helicopter
Manufacturer Sikorsky Aircraft Division of United Aircraft Corporation
Powerplant One Warner R-550 7-cylinder, fan-cooled, radial engine
Thrust 200 HP 149 kW
Length 35 ft 5 in 10.8 m
Height 12 ft 5 in 3.78 m
Weight empty 2,020 lb 916 kg
max. 2,535 lb 1,150 kg
Speed max. 81 mph 131 km/h
cruising 65 mph 104 km/h
Rate of climb 650 ft 198 m/min
Ceiling 8,000 ft 2,440 m
Range 230 miles 370 km
Armament None
Crew Two
First flight January 1942

Source: David Hansonīs American Aircraft of World War II

Jirka Wagner


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