I installed the ventral strakes on my ES and as best I could tell they reduced my cruise speed by about 2 knots (1%).  I'm sure it was no more than that, but could have been less.  I also tested lateral stability and found(feet off the pedals) it increased 30%.  I did this by using ailerons only to put it into a fixed bank angle and then timing how long it took to turn a give angle.  I'm satisfied with the performance, but I think it could have been better with regard to the drag increase.  The strakes are parallel and I'm sure the airflow in that area is not parallel.  I think that is what causes the "excessive" drag.  I thought about building my own single ventral fin, but the tie-down anchor is right where the fin needs to be.

Gary Casey

ES #157

Hello guys

Me again, I just had my first lesson with the Lancair 4p (with JC) and when I took off the plane was wiggling its tail like a happy dog LOL Nothing scary, but this I can imagine could be annoying for passengers.

Now I was looking on the internet and found that Ventral Strakes  were used to fight against those 'yaw' effects.

It suppose to help with turbulence, go-arrounds, full power take offs as well.

My very near future plane (we are almost closing ;) is a newer one, so the tail section was already updated to the latest. 

But looking at my passengers (I fly with my Son and Girlfriend a lot) this could be disturbing for them and I was already thinking of installing the Yaw damper (I have the tru-trak sorcerer) and perhaps also installing those Ventral strakes.

Does anybody have experience (before and after) with those? And would you recommend those? 

Thanks — Ronald Stevens (Cirrus 1100 hours, Velocity 250 hours, Lancair 4p student now with 1 hour LOL)