2. The left and right wings are twisted. When the wings twist, the windward angle is different, the left and right forces are different, and the eagle posture tilts to the left or right, thus turning around;
3. The tail swings up and down from left to right: First, it counteracts the difference of left and right wing resistance caused by the difference of left and right wing elongation and torsion; Second, correct the trend of eagle diving and rising;