Helicopter Sikorsky HR2S-1 Serial 56-017 Register 140318 used by US Marine Corps USMC. Built 1957. Aircraft history and location Aircraft History 140318 US Marine Corps 1957-01-12Sikorsky S-56, c/n 56-017, ff:? del USMC as HR2S-1, 140318, 12Jan57 wfu & soc unk. 1965-05-21soc 21may65 Send Updates Use APP to upload photo @ (optional) When Now? / / Send