Helicopter Sikorsky H-19D Chickasaw Serial 55-1127 Register 56-4252 used by US Army Aviation Army. Built 1957. Aircraft history and location Aircraft History 56-4252 US Army Aviation 1957-09-27Sikorsky S-55 c/n 55-1127, ff:? del US Army as H-19D, 56-4252, 27Sep57. Send Updates Use APP to upload photo @ (optional) When Now? / / Send