Helicopter Sikorsky H-19B Chickasaw Serial 55-569 Register 52-7511 used by US Air Force USAF. Built 1953. Aircraft history and location Aircraft History 52-7511 US Air Force 1953-11-16Sikorsky S-55 c/n 55-569, ff:? del USAF as H-19B, 52-7511, 16Nov53. Send Updates Use APP to upload photo @ (optional) When Now? / / Send