I have a Great Planes "Gene Soucy" Extra 300S ARF and I love it but I do have a one problem I need help with. I seem to be having a roll out problem when I apply a lot of elevator. I will try to describe some examples are:

1. When I perform a simple inside loop from straight and level flight with small to moderate up elevator it performs great. If I do the same thing and add more than 2/3 elevator it will do a "little bump" (quick up and down motion) and then try to perform the loop but roll out to the left when about a 1/3 of the way or so.

2. During tight maneuvers using a lot of control service movement I get a lot of tip stalling from this. If I'm knife edging and want to performa knife edge circle, it rolls out on me as I add the elevator to the mix.

I have checked the elevator alignment, wing and stab incidence, engine thrust line and I can't come with anything. I feel it is getting some sort of turbulance off of the wing but that is as far as I have gotten. Any help will be greatly appreciated.


k9

SOunds to me like you are stalling it.

The bigger the plane the less you can bang around the elevator without stalling it. If you this your first bigger plane then it will just take some time to get used to. You can't slam around a big plane like you can with little 40 sized planes.

This is also directly related to your wingloading. So if you have tried to stuff a bigger heavier engine in there you will stall easier.

Very Cool! Thank you for the advice.

The fullscale airplane is designed to be easy to stall the wing with maximum elevator deflection. It's how airplanes like the CAPS, Pitts, Ultimates, Extras, Edges, Sukhoi's, do the "snap" maneuvers.

The models of these airplanes are the same. They're easy to stall the wing with enough elevator deflection.

It's up to us to tune the elevator throw to suit our wishes for how we want the model to fly.

A lot of experienced flyers reduce the elevator throw until the model no longer snaps out of the tightest loops. Then they increase it back until it just snaps. Then they use dual rates to make it easier to fly the model. They use high rates when they want to do snap rolls and such. They use low rates for landing and the smooth maneuvers. Or they simply learn how much elevator stick to use.

Thanks guys! This is my first bigger plane and this is making sense now. I must still be in the .40 & .60 mode. I appreciate the comments.

k9

Too much elevator too quickly is definitely a factor, as is the weight/wingloading. Those particular planes are not terribly light, so they are going to be even more snap-happy.

I know you said that you checked the elevator alignment, but did you check it at just nuetral? Have you check to make sure that the throws on both of the elevators are exactly the same? It is critical that they be exactly the same or they will induce roll as well as pitch. I had a Cap one time that exhibited the same problem and unmatched throws turned out to be the culprit.

Mike

Thanks again for these great replies. I have checked the control throws and everything is right on. That was my first area to check and it was off a little when using high rates. After hearing the replies and doing some more research, I feel that the answer is in the stall area and/or the "snap-happy" sendrome (I love that title from Bodywerks). I'm just going to work on the "knowing my airplane" part and hopefully get it under control. I do appreciate all the great comments...keep'em coming if you wish. Happy flying!

K9

check left to right balance. one wing could be light. do an upright elevator 4-5 times and if one wing keeps droping add weight to the other wing tip. or lighten the heavy wing but thats hard to do.
rob

da Rock is right on it in the why and the how of it.. Do what he says. Also, check your CG, the more tailheavy you are the worse this condition will be. That is, the more easily the plane will want to snap with increasing elevator input.

Great! Thanks, again. You guys kick butt!