Hello. I have a question. What if I move upward 1/8 "both ailerons? the nose would rise or fall? My problem is that I did a plane and to be aligned the ailerons with the central part of the wing trailing edge, are 1/8 "below the tip of each wing. The plane is balanced according to the plane but flight rises as if it were heavy-tailed.Thanks in advance for your answer.

First let me qualify myself: I have no aeronautical training whatsoever. You will get out of this what you paid for it.

The affect depends on whether you are talking about strip ailerons, or the barn door type, and just how long the wing chord is. In either case the impact should be small. Not noticeable for most of us sport flyers. With strip ailerons, you would be decreasing the wing angle of attack by a small amount. Unless you have a very short chord, too small to make significant change. With barn door type ailerons, you would be building in a bit of washout in the wing (angle of attack greater at the root than at the tip). Not a bad thing at all. Plus, there will be a slight differential effect (more up than down). That too is good.

If it were my bird I would do it in a flash and never think twice about it.

Have fun with it!

Bedford

I did that on some of my pattern planes that are very slick and come in hot in order to slow them down a bit (it induces drag) as well as adds wash out as beepee noted. I have it on a switch, which also adds some elevator compensation (I think up elevator but don't quote me). Agree you should do it, just be aware there's going to be a pitch change until you get it re-trimmed.

I can tell you that raising the ailerons slightly is called "reflexing" when talking full scale. It's done while in cruise on some home built sport planes to decrease drag (through decreased lift), which often let's them pick up a couple miles an hour - a big deal among many in that crowd.

In RC I would guess the effect would be much the same - unless you take it to extremes.

It is so easy to try just do it and see how you like it. I have found that several of my planes (with barn door ailerons) did improve in how they responded when I put in a bit of up aileron at neutral.

Hi!
The ailerons should always be set so the trailing edge of both the ailerons and wing is inline with each other.If the wing is twisted the ailerons should always be set so their trailing edge is in line with the outher part of the wing and not with inner part.

Having the ailerons slighly upwards has nothing to do how the airplane "sits" in the air (tail low or high).

Beg to differ with you jaka. I have flown hundreds of planes of most configurations and size. In ALL of them, any change in airfoil caused a change in "how the airplane sits"; in some cases drastic changes but in most minor change unless you had very large offsets. You change the position of the ailerons, you change the airfoil, simple fact as the center of lift is changed.

Let me qualify myself, I am an Aerospace engineer and a practicing aerodynamicist.

The effect is completely dependent on how the raising of the ailerons changes the flow on the tail. If the ailerons are well outboard and they do not change the flow on the tail you will pitch up. If they do change the flow on the tail it could be anything from pitch up, to do nothing, to pitch down. It can be calculated, but it is sort of complicated. You have to calculate the change in the down wash of the wing at the tail.

Raising the aileron makes the wing generate a larger nose up moment. If the aileron is in front of the tail raising it will increase the angle of attack of the tail, which in turn creates a more nose down moment (in reality it is a smaller nose up moment). It all comes down to which moment is bigger. If the change in the wings moment is larger you pitch up, if the tails moment is bigger you pitch down, if they are about the same nothing happens.

Steven

If the ailerons are full span "strip ailerons" then you have changed the shape of the airfoil for the whole wing. But since you mention the "central part of the wing..." I'm assuming that they are conventional outboard ailerons. In that case raising the ailerons by that much is going to strongly washout the wings. And by "washout the wings" the effect is to make the outer portion of the wings behave like they are strongly warped so that the tips are strongly reduced in incidence angle compared to the inner portion.

This will greatly reduce the risk of tip stalling and in the case of a heavy wing loading aid in preventing any "slow speed surprises". But it is NOT an ideal solution unless it is required to prevent some other more risky situation. And usually such "situations" are linked with an overly heavy wing loading for the size of the model.