Detailed history and photos of helicopter Sikorsky HO4S-3 Serial 55-602 Register 138517 used by US Navy USN Track service timeline and current status. Aircraft History 138517 US Navy 1953-12-17Sikorsky S-55 c/n 55-602, ff:? del USN as HO4S-3, 138517, 17Dec53. Send Updates Use APP to upload photo @ (optional) When Now? / / Send
