Detailed history and photos of helicopter Sikorsky HO4S-3 Serial 55-608 Register 138523 used by US Navy USN Track service timeline and current status. Aircraft History 138523 US Navy 1953-12-03Sikorsky S-55 c/n 55-608, ff:? del USN as HO4S-3, 138523, 03Dec53. Send Updates Use APP to upload photo @ (optional) When Now? / / Send
