Average yaw deviation angle at cruise
 

I'm curious how many degrees from nominal a modern commercial or business aircraft will typically deviate while at cruise (with A/P, yaw damper on) about its yaw axis in straight/level flight. I can't seem to find any data to answer this, though I'm sure it's out there somewhere.

I realize the answer would depend on turbulence level. But say in smooth air, for example, would most modern aircraft maintain +/- 0.5 degrees yaw from nominal during cruise? I should stress I'm talking about the aircraft's cyclical deviation from nominal (not system heading accuracy vs what is entered/displayed). Anyone have some actual data?

From my experience it appears to be zero on the modern jets.
C-130's? Ugh. Constant. Got a ride in the cockpit and asked about the constant heading 'hunting'. "That's normal."

727-100, at higher altitudes, seemed to hunt slightly. Barely, if at all, noticeable.