Error for the control of both the pitch and roll axes was reduced by practice until the joint criterion was met, but 95% of the subjects mastered control of the roll axis first and then achieved criterion performance on the
pitch axis. The ratio of the number of trials to achieve criterion on the
pitch axis to the number needed to master the roll axis was used to show changes of this behavior across the delay and compensation conditions.
It also should be obvious that instability about the airplane's
pitch axis results from placing the CG and CL close together.
The AP-3C is bold in the sense that it flies the
pitch axis strictly by trim, with a trim servo only.
Takeoff was aborted after discovering the control yoke
pitch axis was locked.
In the bargain, somehow, the airplane was becoming hard to control in the
pitch axis. I couldn't figure it out, and was lighting the airplane simply to maintain altitude.
Depending on how stable the airplane is in its
pitch axis, it may naturally pitch down, without pilot intervention; if it's unstable, its pitch may not change.
Most general aviation airplanes show good stability in the yaw axis, a little less in the
pitch axis and very little in the roll axis.
The airplane's speed affects how much downforce is generated, and how stable the airplane is in the
pitch axis.