Helicopter Sikorsky H-19B Chickasaw Serial 55-699 Register 52-7570 used by US Air Force USAF. Built 1954. Aircraft history and location Aircraft History 52-7570 US Air Force 1954-04-29Sikorsky S-55 c/n 55-699, ff:? del USAF as H-19B, 52-7570, 29Apr54. Send Updates Use APP to upload photo @ (optional) When Now? / / Send