Although there are many gains that can be tuned in APM:Copter to get optimal performance, the most critical is the Rate Roll and Pitch P values which convert the desired rotation rate into a motor output. This alone will likely get it flying reasonably well at least in Stabilize mode.
Some general advice on how to tune this parameter:
- Too high and the copter will oscillate quickly in roll and/or pitch
- Too low and the copter will become sluggish
- High powered copter should use a lower gain, under powered copters are a higher gain
