One final "insight" into rudder use in turns .....

The "easiest" turn to make is (and I like that expression) to bank and yank. Roll the plane to the desired degree of bank, and pull back on the elevator (gently) to make the turn. Then, the "purists", and "full-scale" pilots tell you you have to co-ordinate the turn with Rudder.

What they are telling you is two things...

When you bank and yank, the fuselage is not actually pointing in the direction of the turn, it is typically pointing slightly above the arc of the turn. By way of description, if you bank to 45degrees, and then apply just enough elevator to keep the turn "level", the nose of the plane will be pointing up. Ths creates a (slight) inefficiency and you loose a small amount of speed because the wind is hitting the side of the fuselage, rather than running around it. The solution is to use a very little rudder in the same direction of the turn, to "yaw" the plane so that the fuselage is pointed in the direction of travel. This means that you save (a small amount) energy in the turn, which purists will notice, and appreciate, but beginners really don't need to worry about.

The Full-scale pilots need to co-ordinate turns for the above efficiency reasons, but the *real* reason is that if they do not co-ordinate their turns, their passengers will all get air-sick. Co-ordinating the turn properly means that the people on the plane feel the "G" force of the turn perpendicular to the floor of the cabin ... i.e. The passengers are not thrown from side to side when the plane turns.

So, co-ordinated turns are a big thing, but for a beginner, there is no real reason to try to add rudder to a turn.

On the other hand, the rudder is a useful control surface in the air, but IMHO, other than taxiing, landing, and take-off, you can pretty much forget that the (propperly trimmed) rudder even exists (that is, unless you are doing aerobatics).

Back to your original question... When to use rudder or aileron to turn with your avistar...

You CAN turn using just the rudder on the avistar (because of it;s dihedral), but you will not be able to do the same with your next plane. So, learn to turn with the aileron/elevator combination. Bank the plane using ailerons to about 30 degrees (a little aileron until the plane is at the right angle... then return the ailrons to neutral). Then, pull back gently on the elevator, and the plane will execute a nice gentle turn.

gus