Helicopter Sikorsky H-19D Chickasaw Serial 55-955 Register 55-3211 used by US Army Aviation Army. Built 1956. Aircraft history and location Aircraft History 55-3211 US Army Aviation 1956-04-17Sikorsky S-55 c/n 55-955, ff:? del US Army as H-19D, 55-3211, 17Apr56. Send Updates Use APP to upload photo @ (optional) When Now? / / Send