PA 320 shaking up and down

[kamisto]

Hi everybody,

I'm using FSX. Today I installed PA320 CFM. Everything is O'K, but when the aircraft reached the cruising altitude /FL350/ I noticed that it began to shaking up and down - not so much, but it's visible - especially when you look the nose from outside, as if there is a tubulence. However, it lasted during the whole flight /Munich-London/. The aircraft was not overloaded. I didn't notice such a shaking in PA319. I've tried to find some answer, but without success. So what could be the reason for that?
Thanks in advance!

[Kyle Schurb]

Possibly overspeed?

[Ratinho]

Go to cfg of the aircraft. On FLIGHT TUNING change Pitch_stability=1.2 to Pitch_stability=2.5
Done.

[kamisto]

So I changed the value of " pitch stability" to 2.5 and repeated the flight. This time the aircraft behave perfect in the cruising altitude. There was no shaking. Thank you very much Ratinho!!!