Helicopter Sikorsky H-19B Chickasaw Serial 55-519 Register 52-7593 used by US Air Force USAF. Built 1953. Aircraft history and location Aircraft History 52-7593 US Air Force 1953-07-29Sikorsky S-55 c/n 55-519, ff:? del USAF as H-19B, 52-7593, 29Jul53. Send Updates Use APP to upload photo @ (optional) When Now? / / Send