Helicopter Sikorsky H-19D Chickasaw Serial 55-1201 Register 57-1637 used by US Army Aviation Army. Built 1958. Aircraft history and location Aircraft History 57-1637 US Army Aviation 1958-07-26Sikorsky S-55 c/n 55-1201, ff:? del US Army as H-19D, 57-1637, 26Jul58. Send Updates Use APP to upload photo @ (optional) When Now? / / Send