Helicopter Sikorsky HR2S-1 Serial 56-123 Register 145875 used by US Marine Corps USMC. Built 1959. Aircraft history and location Aircraft History 145875 US Marine Corps 1959-03-25Sikorsky S-56, c/n 56-123, ff:? del USMC as HR2S-1, 145875, 25Mar59 wfu & soc unk. 1968-04-30soc 30apr68 Send Updates Use APP to upload photo @ (optional) When Now? / / Send