wrote:
I tried to fly the Cessna 152 with CH Yoke & Pedal. However, I have a
problem that I don't understand. Unlike the real airplane, this one
keeps go up and down for no reason even if I let go the yoke. The RPM
did the same thing, up and down. In the real airplane, I either go up
or down, depend on the position of the yoke & trim. So I wonder what
is
wrong? Please comment.
Thank you.

Have you checked to insure they are calibrated? Are you using Peter
Dawson"s program (FSUIP) SP???? with CH's program. I have had
problems with the two conflicting in the past.

You don't say how much drift you are experiencing. The pots on these
things can drift. I am a former military pilot. I can assure you that
sims don't fly as stable as the real airplane.

Hope this helps,

John