The Sikorsky company developed VS-316 later known as the R-4 as a two-seat helicopter. It has a 3 bladed rotor and radial engine. First flight was January 1942 and it was the first helicopter produced in series with some 130 manufactured. Some were used at the end of the Second World War in Burma and China.
In the US Navy and in the US Coast Guard the type was designated HNS-1. In British service, it was known as the Hoverfly and the RAF set up a helicopter training school january 1945 at Andover.
This XR-4C is a prototype helicopter and was seen at the Steven F.Udvar-Hazy Center of the Smithsonian, Chantilly, Virginia. The right fuselage is open so the structure can be seen.
Photographed 2017 by Cees Hendriks, (C) Copyright IPMS Nederland
At the war museum at Duxford (U.K) also a few photos were made of this RAF Hoverfly Mk.1, KL110 (painted as KK995).
A few scale models exist: in 1/72 scale from MPM and in 1/48 from Special Hobby.
This walk around was first created May 2018 by M. de Vreeze; note the Copyright!