Helicopter Sikorsky HO4S-3 Serial 55-506 Register 138496 used by US Navy USN. Built 1953. Aircraft history and location Aircraft History 138496 US Navy 1953-07-24Sikorsky S-55 c/n 55-506, ff:? del USN as HO4S-3, 138496, 24Jul53. 1954-12-09 w/o 09dec54 Send Updates Use APP to upload photo @ (optional) When Now? / / Send