strange flight characteristics

[DaleM]

I recently purchased the HL Dynamic 400. Directions were sparse but get you through. Directions state 0 deg of down/side thrust. This is a SMALL speed 400 plane and I eyeballed that when I set the firewall.

The horizontal stab sits on top of the vertical stab (t-tail configuration). The horiz-stab "saddle" is curved to conform to the shape of the stab. I eyeballed it level with the wing and drilled the holes. That being said...

The plane is fast for a stock 400 plane. When I go full throttle, it feels like I am having to trim down elevator for level flight. At about half throttle, the "up" pull isn't as bad but seems like it's there.

How can I tell if it's an issue with a need to reset the firewall (add "down" when it already looks level) or if it's an issue with the horizontal stab incidence?? Or with a plane this small am I being too critical and it's something like CG??

Here's a URL to the plane:


http://www.hobby-lobby.com/dynamic400.htm

Thanks for ANY input!
Dale

[Ollie]

If it is properly trimmed for power off glide then all you need is the right amount down thrust to prevent changes in pitch attitude with changes in throttle.

CG location should be used only to establish the desired pitch stability. Decalage should be used only to trim the power-off glide. Thrust adjustments should be reserved for power-on trim. The fine tuning should proceed in that order: CG first, Decalage second, then Thrust offset.

[heli frapper]

would go with Ollie except that unless your very good at resting battery pack exactly in the right place each flight the trim will always seem different

Now a days with these small planes I just compansate with trim as they seem to go out of trim every few flights
probably due small differences
streching affects
servo centring problems
temperature etc

Stephen