I have a freeware plane (a twin jet)that is good in all aspects except when in the approach: it is impossible to hand fly. Any slight aileron or rudder input causes a side-to-side swaying around the roll and yaw axes; very much like what a feather or a leaf does as it falls. Is there anything I can do in the cfg file to help? I was thinking that perhaps the MOI's are too low? Is that a good place to start? I also noted that the drag factors are set around .6, where in all of the other planes I have they are set at 1.0. Any help appreciated. Mike

Just for reference for anyone. I found the answer in Tom Goddrick's Flight Dynamics pdf which can be found through a search on this forum. It was the MOI's which can be easily fixed. In fact, anyone who wishes to tune the cfg file should get this pdf. Mike

I had some difficulty finding that PDF so for others convenience here it is again.http://www.flightsimdownloads.com/pub/FlightDynamics.pdf

Guys, how do you reduce the MOI?Andyhttp://www.x-plane.org/users/mirage/signature2.jpg

The MOI values (roll, pitch and yaw) can be found in the aircraft.cfg. For the side to side swaying, tweaking the roll MOI should do the trick--I would reduce it in 25 pc. increments. But when tweaking it, also try flying at max speed. Reducing MOI too much can give your aircraft "the shakes" when it hits a certain speed.-John

Thanks a lot John! Very much appreciated :-)Andy http://www.x-plane.org/users/mirage/signature2.jpg