AHA !!

A thought just occured while reading another post......
Is it possible that too much tip weight would cause the plane to bank in (outboard wing raise) during the transition from an inside loop to an outside loop during the 8s? basically just after the intersection. (??)
Nose is pointing up for a split section then the plane begins to pitch over for the outside portion. Centrifugal (or centripital ??) force carring the outboard wing tip upwards too much? Enertia??
Oh, my gawd, I'm thinking too much! hahahah
Seriuosly though.......
Thanks!
Bill <><

>A thought just occured while reading another post......
>Is it possible that too much tip weight would cause the
>plane to bank in (outboard wing raise) during the transition
>from an inside loop to an outside loop during the 8s?
>basically just after the intersection. (??)
>Nose is pointing up for a split section then the plane
>begins to pitch over for the outside portion. Centrifugal
>(or centripital ??) force carring the outboard wing tip
>upwards too much?

That's not necessary. All that matters is that it takes some finite time to transition from the positive roll angle that excess tip weight creates in inside turns, to the negative roll angle that excess tipweight creates in the outsides. For a brief time, the lift vector is along positive Y, but the airplane roll angle is such that this is vectored in at you.

Odd you should mention it- it's the second time this week someone asked about this.

Thanks Brett,
I was seeing a problem with Aaron's profile this past weekend that I hadn't seen before with this plane. I was at an angle on the downwind side of the circle and could see the wings roll when he was doing the 8s. He had added tip weight, and had a new engine (Magnum 36 PG set up) which was pulling the plane much better. It is a built up wing RD-1, and needed to be retrimmed with the new engine.
It was an occurance that was evident (so much so that the plane was retired) with his Geo Star. We could never get it trimmed out, and the plane would free flight at times coming out of the transition. I flew it and felt it had too much tip weight, but it wasn't my plane.
I will focus in on this this weekend when we fly the RD-1 again. With some tip weight out. Funny thing is that the plane doesn't drop the wing too much in a hard square corner. Some tip weight will come out then play with the LO trim.
Bill <><

>I will focus in on this this weekend when we fly the RD-1
>again. With some tip weight out. Funny thing is that the
>plane doesn't drop the wing too much in a hard square
>corner.

Maybe you have too much "tab"/flap differential, too?

Hi Brett,
I don't *think* the flap area is a problem on the RD-1, but that is a real possibility on the Geo Star. Might have to take that one out of moth balls soon and work with it. Would be easy enough to check out, and since it isn't *right*, it would be worth the experiment.
Thanks,
Bill <><

>Hi Brett,
>I don't *think* the flap area is a problem on the RD-1, but
>that is a real possibility on the Geo Star. Might have to
>take that one out of moth balls soon and work with it.
>Would be easy enough to check out, and since it isn't
>*right*, it would be worth the experiment.

Well, if it rolls less in hard corners than in soft corners/rounds, excess tab is certainly one possible problem. Tabs and differential flap areas were invented to overcome the opposite problem - rolling more on hard corners than rounds.

Of course, there are other potential issues but that's where I would probably start, in lieu of other information.