Detailed history and photos of helicopter Sikorsky HO4S-3 Serial 55-531 Register 138502 used by US Navy USN Track service timeline and current status. Aircraft History 138502 US Navy 1953-09-16Sikorsky S-55 c/n 55-531, ff:? del USN as HO4S-3, 138502, 16Sep53. 1962-02-16w/o 16feb62 Send Updates Use APP to upload photo @ (optional) When Now? / / Send
