Helicopter Sikorsky H-19B Chickasaw Serial 55-712 Register 52-7575 used by US Air Force USAF. Built 1954. Aircraft history and location Aircraft History 52-7575 US Air Force 1954-05-26Sikorsky S-55 c/n 55-712, ff:? del USAF as H-19B, 52-7575, 26May54. Send Updates Use APP to upload photo @ (optional) When Now? / / Send