An output-feedback H 1 preview controller is proposed. In the flight control operations performed in this study, the disturbance input is estimated by the observer, and the disturbance responses are predicted and restricted using the H 1 preview controller. The proposed system was applied to the longitudinal dynamics of an experimental unmanned aerial vehicle (UAV), which was developed to study the flight control of rocket planes. The accuracy of the estimated disturbance and the performance of the preview controller were validated through performing flight testing operations. From the results of the flight testing operations, the proposed system based on the disturbance model of the pitching moment can be used for the flight control of the experimental UAV.