Dutch Roll Demonstration in the Wind Tunnel

The DRD (Dutch Roll Demonstrator) model features a spherical joint in the centre of gravity that allows yawing, pitching and rolling. The roll axis can be blocked to demonstrate directional stability in the wind tunnel. It also has the possibility of reducing the vertical tail size to demonstrate how this decreases directional stability (obviously) and leads to a divergent roll/yaw coupling mode similar to a dutch roll.

The modes can be excited by a rudder doublet input via remote control.