Helicopter Sikorsky H-19B Chickasaw Serial 55-491 Register 52-7480 used by US Air Force USAF. Built 1953. Aircraft history and location Aircraft History 52-7480 US Air Force 1953-09-09Sikorsky S-55 c/n 55-491, ff:? del USAF as H-19B, 52-7480, 09Sep53. Send Updates Use APP to upload photo @ (optional) When Now? / / Send