Helicopter Sikorsky H-19B Chickasaw Serial 55-661 Register 52-7549 used by US Air Force USAF. Built 1954. Aircraft history and location Aircraft History 52-7549 US Air Force 1954-03-03Sikorsky S-55 c/n 55-661, ff:? del USAF as H-19B, 52-7549, 03Mar54. Send Updates Use APP to upload photo @ (optional) When Now? / / Send