Yaw damper-does it do anything?

[Gringo6]

I know what a yaw damper does in  real life, but what does it do in FS9?

Several FS9 jets have a yaw damper switch (usually on the autopilot), but I cannot detect any difference in flight characteristics with the switch on or off.

Is it just cosmetic or does it really do something that I just cannot detect ?

I've even checked the ".air" file to make sure it is enabled.

Thanks,

[DaveSims]

It probably does, but its hard to tell since FS does not seem simulate dutch roll.  If you have it turned on while on the ground, you can see some rudder movement by the yaw damper during turns.