I have a b727 (Vistaliners) in which the overspeed setting seems wrong - the whole a/c judders in flight if I exceed certain speeds - but the speeds are not correct. Under 10,000' for instance, much over 220 KIAS and the shaking starts. Is it possible to fix this or is it written into the model? If it's in the .air file, what are the parameters I'd need to edit? - I can't see anything in AirEd ...Thanks,Martin

I have the B721 and B722 from Vistaliner. In the aircraft.cfg files for both of them, under [Reference Speeds], are two speed limit values. I believe these are the ones that determine the overspeed setting. Check yours to see if they agree.max_indicated_speed=341max_mach=0.82Your speed of 220 KIAS is also near or over the limit for takeoff flaps, but I don't remember if that affects the flight model. Of course, I'm sure your flaps are up well before 10,000 feet, but just thought I would mention it.Regards,JerryH

Yes, no flaps by then! :-)I have this. Is yours the same?:flaps_up_stall_speed=132.000full_flaps_stall_speed=105.600cruise_speed=413.099max_indicated_speed=341.000000max_mach=0.82I have set the cruise speed to less than the max indicated speed, but as I said, I am going nowhere near that fast when the a/c starts to shake!M.

My reference speeds are identical to yours for both versions of the B727. I'm totally out of ideas at the moment. When I get the time later today, I'll fly the bird and test it at higher speeds to see if I can make it shake.Please let us know if you ever figure it out.Regards,JerryH

Is FS9 set to display indicated airspeed in its options ?

Yes - but I only get the problem with this one a/c so I doubt if any global settings are at fault?Martin