I found this online. Called a scissors tail. [attachment=0:1gh8fx1z]ScissorTail.jpg[/attachment:1gh8fx1z] Supposed to keep the turbine turned into the wind during turbulence. Claiming up to 15% improvement in power. Seems also the same as the 15% dead zone of a normal tail that keeps it seeking all the time in turbulence. And then the light went on while looking at it. :idea: Would it be possible to design this with one side spring loaded? :geek: And make an easier furling system.