Helicopter Sikorsky H-19B Chickasaw Serial 55-594 Register 52-7518 used by US Air Force USAF. Built 1953. Aircraft history and location Aircraft History 52-7518 US Air Force 1953-12-03Sikorsky S-55 c/n 55-594, ff:? del USAF as H-19B, 52-7518, 03Dec53. Send Updates Use APP to upload photo @ (optional) When Now? / / Send