Unique Properties of Lateral-Directional Stability and Control in Birds

There are specific features in birds which lead to unique properties of lateral-directional stability and control. One is the lacking of the vertical tail. It is shown that this primarily has an impact on yaw stability and damping. In order to achieve adequate levels in yaw stability and damping, the wing plays an important role. Another property concerns the size of birds. It is shown that their size with respect to their aerodynamic configuration is such that there is a very fast behavior concerning the rotary dynamics. This particularly holds for the rotary dynamics in the roll axis. Significant factors in this respect are identified and dealt with.