The Knife Edge maneuver and the Immelman maneuver make use of the rudder. If you can circle the field in Knife Edge it could be that you have "arrived". I chuckle every time I use the rudder when I'm flying my Flying Lawnmower and make a turn. It does not have a rudder! My rudder usage seems to be on auto pilot. On at least three occasions I have had a plane in the air when a failure occurred with the ailerons. Two were with student planes. I was able to safely land the planes using the rudder for turns.