Sikorsky S-52   NC92823                               (c/n  1)


                                           Even on the original print the registration of this, the prototype S-52 is blurred.  It is barely
                                           discernible in the enlargement (below).   First flown in 1947, the design was commenced as
                                           early as 1945.  It was a two-seater (must have been a bit cramped) powered by a 178 hp
                                           Franklin engine.  It was the progenitor of a limited run of 4-seat military machines (civil models
                                           S-52-2 and production S-52-3).    Four were evaluated by the US Army as the YH-18A
                                           (of which two were later converted to XH-39s),  79 were built for the US Navy as HO5S-1s
                                            and 8 went to the Coast Guard as HO5S-1Gs.