Helicopter Sikorsky HO4S-3 Serial 55-704 Register 138595 used by US Navy USN. Built 1954. Aircraft history and location Aircraft History 138595 22May54 US Navy 1954-05-22Sikorsky S-55 c/n 55-704, ff:? del USN as HO4S-3, 138595, 22May54. 1957-01-19 Accident crashed into Ross Sea, with HU-2 Det 69 during Operation Deep Freeze II, while operating from USS Glacier. HU-2 Send Updates Use APP to upload photo @ (optional) When Now? / / Send