What's the Angle of the Dangle???

When you hang a model by it's leadouts, it dangles a certain angle down from the horizontal. Maybe 3 or 5 degrees??? Is this not a significant number in pre-flight trimming ????

As I figure, it depends only on CG and leadout position. If it hangs straight or nose-up, you eat the plane. Too much nose-down, and it pulls your arm out.

There much be a target-angle. Any thoughts?

no, depends on rudder oofset and lines drag

Hmmm. What if you have no rudder off set? Line drag is always there. I tried the hanging by the lines trick on a bench trim. Something I learned on here instead of at the field, where more often than not, it's too late. I set one model at 3 degrees using a protractor and chalk line as a plumb. I set the tip weight where the out board wing would slowly tip onto its tip, with the lines and reel set in the middle of the inboard wing to simulate line weight and drag. CG, stastic, was set at root chord peak of the airfoil.
Lo and behold!! This profile Cavalier flew right off the board. Best I've ever had. However, never, ever launch with tall Dandelions between you and the plane. Running from a plane, strapped to your wrist, no escape, is not too funny, except to those watching. But the slight downward slope of the hanging airplane is a good starting point towards trimming it. I'm still learing, but this works for me.

>When you hang a model by it's leadouts, it dangles a certain
>angle down from the horizontal. Maybe 3 or 5 degrees??? Is
>this not a significant number in pre-flight trimming ????
>
>As I figure, it depends only on CG and leadout position. If
>it hangs straight or nose-up, you eat the plane. Too much
>nose-down, and it pulls your arm out.
>
>There much be a target-angle. Any thoughts?

I think there *is* a target angle, and it's given by the nomographs that Mild Bill published, and can be calculated by Pete Soule's "lineII" program (both based on the same analysis). It's definitely NOT the same for every airplane/line combination.

Pete Soule's program is not on the Internet anymore - at least not at the address given before.

I wish someone would post it on the PAMPA site, so we all could benefit.

>Pete Soule's program is not on the Internet anymore - at
>least not at the address given before.
>
>I wish someone would post it on the PAMPA site, so we all
>could benefit.

That would be great, except for the copyright issue.

Brett

p.s. I went and checked, and was able to download it. Go to

http://www.geocities.com/ama271/Aeronotes/

and you should get a directory listing. Then scroll down to lineII.exe and downlaod it (select "save to disk"). Then unzip and enjoy. It is still copyrighted, so don't post it without permission.