Helicopter Sikorsky H-19B Chickasaw Serial 55-363 Register 51-3911 used by US Air Force USAF. Built 1953. Aircraft history and location Aircraft History 51-3911 US Air Force 1953-03-17Sikorsky S-55 c/n 55-363, ff:? del USAF as H-19B, 51-3911, 17Mar53. Send Updates Use APP to upload photo @ (optional) When Now? / / Send