Helicopter Sikorsky HRS-1 Serial 55-081 Register 127841 used by US Marine Corps USMC. Built 1951. Aircraft history and location Aircraft History 127841 US Marine Corps 1951-11-30Sikorsky S-55 c/n 55-081, ff:? del USMC as HRS-1, 127841, 30Nov51 1956-11-29 w/o 29nov56 near Irvin Lake, CA Send Updates Use APP to upload photo @ (optional) When Now? / / Send