Helicopter Sikorsky HO4S-3 Serial 55-553 Register 138506 used by US Navy USN. Built 1953. Aircraft history and location Aircraft History 138506 US Navy 1953-10-21Sikorsky S-55 c/n 55-553, ff:? del USN as HO4S-3, 138506, 21Oct53. Send Updates Use APP to upload photo @ (optional) When Now? / / Send
