PURPOSE:To obtain an autopilot of a flying object which eliminates the need for high-precision acceleration and an electric interface with a mother equipment and utilize a special Pitot static pressure tube, by varying the gain of an autopilot according to operation altitude and a speed. CONSTITUTION:The output of the Pitot static pressure tube 16 provided to the autopilot is converted into electric signals by total pressure and static pressure gauges 29 and 30, and a strain gauge 22 measures air force operating on plural small blades fitted to the Pitot static pressure tube. This air force is transduced into voltages by dynamic strain gauges 27 and 28 for a pitch axis and total pressure, and altitude and speed computers 33 and 34 find the altitude and speed from the difference between the total pressure and static pressure. Further, the outputs of the dynamic strain gauges 27 and 28 are converted into estimated acceleration by acceleration computers 31 and 32 which calculate pitch-axis and yaw-axis acceleration. Then, the pitch-axis and yaw-axis rate gyros 1 and 5 detects the angular speed of the frame body and the gain of the autopilot is adjusted by a gain adjusting device 13 according to the altitude and speed information.