Helicopter Sikorsky H-19B Chickasaw Serial 55-640 Register 52-7537 used by US Air Force USAF. Built 1954. Aircraft history and location Aircraft History 52-7537 US Air Force 1954-03-02Sikorsky S-55 c/n 55-640, ff:? del USAF as H-19B, 52-7537, 02Mar54. A photo exists of 27537 in MASDC wearing N2256G 1989-06 A Pima Air and Space Museum Exhibit To Pima Air and Space Museum by Jun 1989 Send Updates Use APP to upload photo @ (optional) When Now? / / Send