There is large time delay in'man-in-the-loop' unmanned aircraft vehicle (UAV) system controlled by satellite communication. Time delay can lead to the system being unstable. For improving the performance of the delayed system, it needs to be compensated. Considering the character that the UAV is operated through man-machine interface, the future aircraft state was predicted based on modeled-aircraft predictive algorithm. The estimated state variable was used as the output of the delayed system to compensate the transmission delay. An aircraft's pitch angle control loop was designed. The simulation results indicate the compensation algorithm used is effective for decreasing the effect of time delay on systems.