Helicopter Sikorsky HO5S-1 Serial 52-021 Register 126696 used by US Marine Corps USMC. Built 1952. Aircraft history and location Aircraft History 126696 US Marine Corps 1952-04-30Sikorsky S-52-3, c/n 52-021, ff:? acc BuAerRep (BAR) East Hartford, CT, 30Apr52 del USMC as HO5S-1, 126696, 07May52. 1956-09-28soc 28sep56 Send Updates Use APP to upload photo @ (optional) When Now? / / Send