Helicopter Sikorsky H-19B Chickasaw Serial 55-564 Register 52-7506 used by US Air Force USAF. Built 1953. Aircraft history and location Aircraft History 52-7506 US Air Force 1953-11-05Sikorsky S-55 c/n 55-564, ff:? del USAF as H-19B, 52-7506, 05Nov53. Send Updates Use APP to upload photo @ (optional) When Now? / / Send