Helicopter Sikorsky HRS-1 Serial 55-046 Register 127810 used by US Marine Corps USMC. Built 1951. Aircraft history and location Aircraft History 127810 US Marine Corps 1951-07-25Sikorsky S-55 c/n 55-046, ff:? del USMC as HRS-1, 127810, 25Jul51 w/o 06mar54 Send Updates Use APP to upload photo @ (optional) When Now? / / Send