Helicopter Sikorsky H-19B Chickasaw Serial 55-485 Register 51-3964 used by US Air Force USAF. Built 1953. Aircraft history and location Aircraft History 51-3964 US Air Force 1953-08-31Sikorsky S-55 c/n 55-485, ff:? del USAF as H-19B, 51-7564, 31Aug53. Send Updates Use APP to upload photo @ (optional) When Now? / / Send