Sikorsky R-4 Hoverfly           42-107237

                                    

                                        The R-4 was the only helicopter to see active service (albeit limited) in WW II, mainly in the Far
                                        East (CBI) theater.  The above image probably illustrates the first YR-4B 42-107237, however
                                        the serial (normally on the rear fuselage) appears to have been airbrushed out, a fairly common
                                        practice for experimental types during WW II.