Helicopter Sikorsky H-19D Chickasaw Serial 55-649 Register 52-7621 used by US Army Aviation Army. Built 1954. Aircraft history and location Aircraft History 52-7621 US Army Aviation 1954-02-15Sikorsky S-55 c/n 55-649, ff:? del US Army as H-19D, 52-7621, 15Feb54. Send Updates Use APP to upload photo @ (optional) When Now? / / Send