Translations:KAVAN Alpha V2 1500mm - Instruction manual/93/en

From KAVAN RC Wiki

Rudder of a model without ailerons (you might be already familiar with) controls the angle of bank, which then controls the rate of turn. Natural stability of your model keeps the wings level in normal straight flight. Since your ALPHA 1500 V2 features a “full house” controls including ailerons that are the main means how to control the angle of bank, the use of the rudder is slightly different. You can even start to control your model without use of the rudder - but you will learn lately the correct coordinated turn actually requires both aileron and rudder inputs.