RE: jett powered, but a bit off topic....
In control line stunt it is known as the "Al Rabe rudder". The rudder can be adjusted to remove all of the prop gyroscopic precession from the propeller for inside and outside manouvers.
I would guess that 99% of all RC fliers don't use the rudder when doing loops, but you will find that when you do the airplane tracks better. Most noticeable on draggy airplanes with big props.