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Old Jul 01, 2002, 02:29 AM
Petri Nygren is offline
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Senior Member
Finland
Joined Feb 2001
584 Posts
Not quite so

Quote:
Originally posted by TedLarson

Next, I don't recommend using flaperons. The effect flaperons have on flight is usually disasterous. When you drop both your ailerons, on a plane, you are essentially inducing a negative washout in both wings, which will make your plane VERY sensitive to tip stalling the slower you go. I have seen at least 3 separate people start flying with flaperons, and crash while landing due to a tip stall. Also, you are wanting to land in a shorter distance. Flaperons will make the plane more floaty, and more prone to ground effect also....again...also increasing your chance of a tip stall.

If you can setup Airbrakes, then this is the way to go to solve your short landing problem.
- Ted


Ted,

Most E-pylon racers I know of have ailerons that start from the wingroot and end some distance from the tip. Thatīs how it is in my Stinger and also in Flying Catīs Python. When you use flaperons in such layout, you generally donīt have to fear tipstall. I bet all the flaperon crashes you saw happened to models with wingtip ailerons. When you have aileron in the tip and drop them both down, you effectively create wash-in in your wing and get immediate tipstall danger.

In Stinger, aileron chord is increasing towards the wingroot and that coupled with the fact that aileron does not extend all the way to the tip, actually increases the wash-out when flaperons are lowered.

Moreover, when you use full span - variable chord - non wingtip reaching aileron as an airbrake by taking them up, you actually create highly undesireable wash-in to your wing! Dont do it -its a quick way to disaster! Its meant only for wingtip ailerons like found in most gliders.

I would also prefer having a good stall AoA (high Clmax) in landing, and thats actually made worse by full span airbrake setup. In other words, when you take the ailerons up, your wing stalls earlier. Not nice at all.


Petri
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