Another reason is that there are limits to how long and skinny a wing can get before it is no longer able to carry the required loads. The ailerons and elevator are controlled using a single control stick between the pilot's legs. The rudder, as in conventional aircraft, is controlled using foot pedals. Mouse-over the control names to see where they're located on the glider. Ailerons Ailerons are the movable sections cut into the trailing edges of the wing.
Ailerons operate in opposite directions on each side of the plane.
If the pilot wants to roll the plane to the right, he moves the control stick to the right. The difference in lift between the two sides causes the plane to rotate about its long axis. The elevator is the movable horizontal wing-like structure on the tail. It is used to control the pitch of the plane, allowing the pilot to point the nose of the plane up or down as required. The rudder is the vertical wing-like structure on the tail.