Is it just a bad design or is the plane possessed by some pitch demon? At full throttle it will climbs up at a pretty alarming rate and dive at low throttle. This is the first plane I've considered a real handful to fly. Magazines reviews from years back stated this kit had no bad habits. It's a Byron GeeBee R2 with a G62 built as per the plans. Does this plane simply need more down thrust?

Thanks,
Shaun

Some downthrust would not hurt but a strong power related pitch is often a sign that there is too much up trim or wing to stab anglular difference (called decalage) to compensate for a forward balance point. Moving the balance back requires adding down trim and that will reduce the power related pitch reaction.

For a GeeBee I would inquire with other owners as to where they balanced the model. Or if you wish to experiment with this yourself then move it in very small increments like 1/4 inch at a time until the model can be dived at low power and upon stick release will pull up to level over about a 200 foot elevation change from a 45 degree dive. If you can dive it like this and it pulls up more sharply then it's a good sign that you are balanced too far forward. Moving the CG back and retrimming the elevator will lessen the power related pitching problem.

Byron had fixed the CG by drilling it into the fuse so I never messed with it. Sounds like this could be the problem, I didn't think of a positive elevator compensating for a forward CG. As soon as the snow clears I'll give it a try. Any other GeeBee owner's out there?

Thanks,
Shaun Bell

You might check with the Giant Scale forum guys. I suspect a lot of them don't bother dropping by here. For a model as extreme as the GeeBee there may be other issues that require the CG be further forward than "proper" trim on a more conventional model would dictate.

When you said that Byron drilled it into the fuselage I'm reminded of the guy that wanted to sell stickers of the little white and black 4 slice "pie" symbol so many plans use for the CG indicator. The idea was you could move the CG to whereever you wanted just by moving the sticker....