Helicopter Sikorsky H-19D Chickasaw Serial 55-1222 Register 51222 used by Royal Thai Army. Built 1959. Aircraft history and location Aircraft History 51222 Royal Thai Army 1959-01-26Sikorsky S-55, c/n 55-1222, ff? reg Sikorsky as N9F, 1959 accepted RTA as H-19D, 51222, 26Jan59 left factory gates 03Feb59. Send Updates Use APP to upload photo @ (optional) When Now? / / Send