Helicopter Sikorsky HRS-1 Serial 55-017 Register N4781S 127783 used by US Navy USN. Built 1951. Aircraft history and location Aircraft History 127783 US Navy 1951-04-27Sikorsky S-55 c/n 55-017, ff:? del USN as HRS-1, 127783, 27Apr51 xfer NATC unk xfer NACA unk fate unk. N4781S - ex 127783 Send Updates Use APP to upload photo @ (optional) When Now? / / Send
