Interesting, that....

I don't know the Xs and Os of it, except it creates a bit of a seperation and drag there. I know what the effects are. It helps smooth out the choppy bumps in severe turbulence. It also acts like expo, helps keeping the wings "feeling" centered and set.

Of course, if you go too far, bad things happen. What exactly can depend on way too many variables to list, but the first thing I noticed was snaps got a little more difficult to nail fast and accurately. Like it took more to stall the wing to induce the snap.

But, if you play with the airfoil thickness you can tweak that part too. To a certain extent.

I noticed one designer (Hebert) using a tapered angle trailing edge. That's pretty interesting to me.

Back to the thick TE, the late Jim Ivey and I did some field tests on this. We flew at a field notorious for bumpy turbulence above the trees. Our planes were bumping around quite a bit. Bruce Thoman had an (Osmose?) with thick TEs and it didn't exhibit this particular trait. (May it RIP). We then glued some stock to the TEs of one of Jim's planes and tried it out....and it worked. Been using a form of it ever since. The only question is how much, and where.

-M