Helicopter Sikorsky HRS-1 Serial 55-036 Register 127801 used by US Marine Corps USMC. Built 1951. Aircraft history and location Aircraft History 127801 US Marine Corps 1951-07-03Sikorsky S-55 c/n 55-036, ff:? del USMC as HRS-1, 127801, 03Jul51 1953-09-01 w/o 01sep53 Ream Fld, CA Send Updates Use APP to upload photo @ (optional) When Now? / / Send