Detailed history and photos of helicopter Sikorsky HO4S-3 Serial 55-723 Register 138600 used by US Navy USN Track service timeline and current status. Aircraft History 138600 US Navy 1954-06-01Sikorsky S-55 c/n 55-723, ff:? del USN as HO4S-3, 138600, 01Jun54. Send Updates Use APP to upload photo @ (optional) When Now? / / Send
