I cant find the old post, so I am opening a new...I tried now to control the speed on the PMDG737 manually, but it still wont work... When I give max throttle the speed automaticly decreases when it reaches about 280 IAS (455 TAS) at FL350.Cant I control the throttles manual when I am on cruise?

Did you try turning off the A/T?It's switch is right above the Flight Director.Regards,Mark

Yes, I turned of the AT, but still the throttles continued increasing and decreasing..

Ok that never happened to me. Just to confirm, the top left of the PFD is empty? That's where the engaged A/T mode is displayed (or ARM when the A/T is armed).If that's the case, I can't help ya, sorry.Regards,Mark

I think that's a safety feature of the NG series, it won't let you overspeed.

Hmmm, hehe 280 kts IAS on FL350.... Overspeed?? ;)