Detailed history and photos of helicopter Sikorsky HO4S-3 Serial 55-724 Register 138601 used by US Navy USN Track service timeline and current status. Aircraft History 138601 US Navy 1954-06-08Sikorsky S-55 c/n 55-724, ff:? del USN as HO4S-3, 138601, 08Jun54. Send Updates Use APP to upload photo @ (optional) When Now? / / Send
