Frustrated by level bombing. Please HELP!

[jimbop]

Originally Posted by Untamo

One problem still bothers me:
How do you get the course autopilot to fly straight? .. I set the gyro to compass heading, set the course to same and engage autopilot. The plane starts to weave right and left. It goes in the right direction, but keeps banking from side to side in a sidewinder manner. I've tried to force the plane to go straight with the stick and also with minor changes in the AP heading and it works for a while, but then again it starts to bank.

Is there any way to calm it down?

As Chromius said you need to trim well. Do not skimp on this step - good trim is very important before activating autopilot.