Hello Simon; Yes it does have the rotary knob on the top right of the casing. Also it has three mixes, these being INH = inhibit, FL = flaperon, V = v tail, EL =elevon, CL = clear. Flaperon is what I have selected, but no flap trim, is selectable as far as I can see, or any other function to inhibit the rotary knob! Regards Barry