Gatekeper, big planes do not have this. This is just the easiest, cheapest way to correct the problem in a rc plane. Real planes have what's called washin built into the left wing. Ths means the left wing produces more lift, preventing the tendancy to roll left. As a result of the different airfoil, the left wing produces more drag, witch makes the plane want to turn left (as if you were giving a little left rudder). The compensation is built into the vetical stabilizer so at level flight cruising, the plane goes straight. Now if your in a steep climb (take off) the vertical stabilizer does not get as much prob blast or wind b/c of the angle of attack of the wings. This means on take off or a steep climb, you must give a little right rudder to maintain atraight tracking. Sorry for rambling.