RE: Side thrust and down thrust on a patternplane
Well think about it. It's the prop wash hitting the vertical fin and rudder that cause most of the effect, in addition to the side of the fuse.
Now, flip the airplane over inverted. The airflow is spiraling the same direction, except now the vertical fin is on the bottom, backwards.
That's an oversimplification, but it's the easiest way to explain it. It works. But it's a fine line between thrust and rudder trim, and neither is ever perfect. Even with all the mix in the world, at some point in some attitude, you're going to have to get up on the sticks and fly the plane. The thrust just makes it easier on the pilot in most circumstances.
Wing incidence is another area of set up you can discuss all day. Ever noticed how hard it is to get a clean spin break with your wings set at 0? Now give them +.5 deg positive, and voila....sweet spin break. But in FAI, the spins are inverted......OOPS! So once again, well......
Set up is the most personal part of pattern. If you fly 100 peoples planes, you'll experience 100 different setups. Especially as you get closer to the top. Use what works for you, but above al try EVERYTHING. Just don't do anything drastic, so you can get back to where you were if you hate it.
-Mike