G'day SilvermanSteve

Some time back I had a real flying lesson on a Cessna 150. My instructor gave me a basic lesson on what the control surfaces do. It was quite interesting and as a result I now understand what is happening when I am flying my models.

A plane (as I am sure you know) can do three things. It can Roll side to side, it can Pitch up and down and it can Yaw around a vertical axis. It has three sets of control surfaces which affect these movements.

But. And this is where the story really starts, each one as a Primary effect and a Secondary effect.

The ailerons primarily cause the plane to roll but the secondary effect is that it also causes the plane to yaw.

The rudder primarily causes the plane to yaw but it also causes the plane to roll.

The elevators cause the plane to pitch up and down but also effect the air speed.

So the ailerons and rudder both cause the plane to roll and yaw. The amount that they have their secondary effect depends on the wing dihedral (the angle between the wings) and also where the wing is places. So a plane with a high wing with lots of dihedral (like many trainers) will roll a lot when the rudder is used. Your Easystar is like this and so it can get by without ailerons as its rudder causes it to roll quite a bit and this allows it to turn without ailerons.

A plane with a flat wing placed near the centre of the fuselage will not roll a lot when the rudder is used and it needs its ailerons to allow it to complete a banked turn.

Hope this helps a bit.

Mike.

PS. I have an Easystar with a brushless motor. It is a really great little glider - much better than its price would suggest. Performance with the original motor is a bit tame.