Helicopter Sikorsky H-19B Chickasaw Serial 55-615 Register 52-7524 used by US Air Force USAF. Built 1954. Aircraft history and location Aircraft History 52-7524 US Air Force 1954-01-05Sikorsky S-55 c/n 55-615, ff:? del USAF as H-19B, 52-7524, 05Jan54. Send Updates Use APP to upload photo @ (optional) When Now? / / Send