Helicopter Sikorsky H-19D Chickasaw Serial 55-993 Register 55-4941 used by US Army Aviation Army. Built 1956. Aircraft history and location Aircraft History 55-4941 US Army Aviation 1956-08-04Sikorsky S-55 c/n 55-993, ff:? del US Army as H-19D, 55-4941, 04Aug56. Send Updates Use APP to upload photo @ (optional) When Now? / / Send