Wing and stabilizer profile and orientation

I have a question the the ones out there who are already sucessfully foiling. For the kite and surfoil, the rear stabilizier is always mounted upside down, so that it is creating downthrust, but gives better stability, as the force in kiting and surfing is way above the foil. For efoil, the driving force is nearly inline with the foil. So in my opinion the rear stabilizer should be mounted like in airplane, not upside down.
Hor are the rear stabilizer mounted on your efoils??


On my first foil, Neil pryde one, it was with few angle, and really unstable. (due to too small surface of wing). I gave some more angle with washer, it was better.
Can not explain why but it was working as describe in data sheet of manufacturer.

In an airplane, for stability reasons you need to have the Center of Gravity in front of the wing center of lift so that any disturbance creates a moment that restores equilibrium. The drawback to that is that in order to stay level, your tail has to pull down to keep the airplane level (see picture).
Our foil arrangements replicate that setup exactly and, the more the tail pulls down the less efficient but the more stable the setup.
Another solution is to have a canard wing in the front of the airplane pulling the front of the airplane up instead of a tail pulling the back of the airplane down but that comes with its own set of issues.

I hope this helps.


Image result for aircraft pitch stability

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