Pitching and rolling
 

Hi,

During plain old aileron rolls, my pattern plane require almost no elevator input to keep the nose on the horizon and the roll straight on the longitudinal axis. My Cap 232 required much larger elevator inputs. What causes this type of differenc? What can be done to tame it?

Thanks,
Glenn

RE: Pitching and rolling
 

The CAP is an aerobatic stunt plane; they are designed to be unstable so they can accomplish the stunts.

Pattern planes are designed to be SMOOOOOOOTH...

RE: Pitching and rolling
 

Is your CAP balanced properly? If not, do it.
Is it trimmed for level flight with no control input ( "look Ma, no hands" )? Did you have to apply a lot of UP or DOWN elevator trim?
If not, trimmed, make sure you trim it.

If it is already trimmed and well balanced, what happens on inverted flight? Do you have to apply up or down elevator to keep it flying level? If so, you might need to change the wing incidence, particularly if you have had to apply a lot of trim for level flight upright.

Luis

RE: Pitching and rolling
 

Luis,
The plane (4 flights to date) was balanced at the forward end of the recommended CG envelope. The plane flew hands off with very minor trim adjustments. I'll be learning the plane some more this weekend. I will let you know how inverted flight goes.

Thanks,
Glenn

not entirely accurate
 

>The CAP is an aerobatic stunt plane; they are designed to be unstable so they can accomplish the stunts.
>Pattern planes are designed to be SMOOOOOOOTH...

The CAP isn't unstable. The airplane must be stable or we couldn't fly them. Most aerobatic airplanes whether scale or the present design trend toward long fuselages and smaller spans will have the CG just a few percent ahead of the Neutral Point. It makes both airplanes fly with less elevator trim either upright or inverted and requires less elevator input to accomplish maneuvers. I have a CAP that is just as smooth as my pattern ships (at least until I decide to interfere with it's flight path).

What will happen with the airplane that is balanced too far forward is that it flies level upright with a fair amount of up elevator trim. When the airplane rolls inverted it needs more down elevator to maintain inverted level flight. During a roll this results in a lot of elevator action and stick pumping.

I have one airplane balanced well aft and you just had to breath on the sticks to do rolls level. I put a heavier motor in and didn't pay attention to the new center of gravity. It now requires a lot more stick movement.