Helicopter Sikorsky H-19B Chickasaw Serial 55-621 Register 52-7530 used by US Air Force USAF. Built 1954. Aircraft history and location Aircraft History 52-7530 US Air Force 1954-01-15Sikorsky S-55 c/n 55-621, ff:? del USAF as H-19B, 52-7530, 15Jan54. Send Updates Use APP to upload photo @ (optional) When Now? / / Send