Helicopter Sikorsky H-19D Chickasaw Serial 55-1278 Register 59-4974 used by US Army Aviation Army. Built 1959. Aircraft history and location Aircraft History 59-4974 US Army Aviation 1959-10-12Sikorsky S-55 c/n 55-1278, ff:? del US Army as H-19D, 59-4974, 12Oct59. Send Updates Use APP to upload photo @ (optional) When Now? / / Send