Went flying in very cold, damp and calm air. Had to deal with my own turbulence to an excessive degree. Stepping back of course helps but this is a fairly new airplane and the turbulence was very large. That raises the question, is there a particular airplane design, weight, size...color...that is more or less turbulence prone or handles turbulence better or worse?
It's counter-intuitive but the big factor seems to be prop diameter. I would have expected it to be the weight, since there should be a lot of effect of turbulence generated by the wing in the corners, and the heavier it is the more induced drag and lift and the more the air is disturbed. But the prop diameter seems to matter a lot more.
I think the issue is this - the turbulence from the wake moves out of the track of the airplane, but the prop wake hangs in the track. In humid conditions or when you have exhaust hanging in the air, you can actually see where the wing wake goes, and it seems to move something like a foot or so off the track (in the direction the air is displaced to create lift, e.g. towards the bottom of the airplane on an inside loop). There's no particular reason that the prop turbulence would move out-of-track, it seems to mostly spiral around on-track. When flying in dead calm, I will make sure that if I miss the track, I miss it to the *inside* of the maneuvers, like, make the loops progressively smaller (or at least make extra-sure they don't grow).
Paul Walker provided the insight to this, both intentionally and unintentionally. The first was intentional - running a 9-4 Rev-Up on his 45FSR/Bad News at the Reno NATs. He can add but he had essentially no issues with turbulence. The second (and when I hit on the idea) was unintentional, either the 99 or 01 TT, where Paul was first up in the morning on qualifying day and it was *dead*, and I mean *dead*. By the time he was done there was a hemisphere of castor mist hanging in the air. With that, you could see the turbulence coming off the wing, and it always went off-track about a foot or so, and stopped. Every time he overshot the track, you could see the airplane fly through the turbulence, and every time, he got a big bump. The rest of it was an almost continual low-level rattling around through the prop wake. This was with a PA61/Aussie Mod and *probably* a 12-4 or something like that.
Brett