Helicopter Sikorsky H-19B Chickasaw Serial 55-511 Register 52-7486 used by US Air Force USAF. Built 1953. Aircraft history and location Aircraft History 52-7486 US Air Force 1953-09-17Sikorsky S-55 c/n 55-511, ff:? del USAF as H-19B, 52-7486, 17Sep53. Send Updates Use APP to upload photo @ (optional) When Now? / / Send