What does the rudder flap serve as? I am playing a flight simulator and the rudder seems to do nothing....

LEFT and RIGHT or UP and DOWN depending upon the orientation of your plane.

I'm guessing G-2,... try high rates on an edge or an extra. The rudder is VERY important later on.

Why? what does it do while your in the air?

Idealy it controls yaw. In straight and level flight, moving the nose left or right. (if knife edge that's gonna be up down) However many planes have roll coupling with the rudder (more or less any trainer). This causes the rudder to also roll the wings. The rudder is among the last control surfaces to loose authority at slow speed, so it is important at slow speed. Aswell, at slow speed, ailerons could stall a wing and cause a tip stall. The rudder will be less likely to do so. However... no always. A snap roll for instance is often initiated with elevator and rudder. As you might be gathering, there's not a perfect anwser.
2 sites I very quickly pulled up on google with a search for flight dynamics
http://en.wikipedia.org/wiki/Flight_dynamics
http://www.ueet.nasa.gov/StudentSite...sofflight.html
Both are very basic but it's a good point to jump off from.
-John

What sim? We'll want to avoid that one.

I've used flight games where the rudder did funny things, like cause yaw without changing flight path, etc. (I think that was one of the WWII interactive games, like Air Warriors or one of the others.)

The rudder on our models causes the plane to yaw (turn left or right) and change direction. If the wing has dihedral, some roll will accompany rudder use. If your simulator doesn't cause the same, you won't be able to learn to use the rudder with that sim.

Good luck,
Dave Olson

Flight games... lol

What flight simulator program and what airplane within the program are you flying? Some planes have more rudder response than others,, some less. Are you flying a trainer, a sopwith pup, an Extra, GeeBee? They are all VERY different. Hopefully you are flying a trainer on either AFPD, Reflex XTR, Realflight G2 or G3.

You can learn flying a trainer ignoring the rudder. The rudder will give you smooth turns, but it is not truly necessary to simple flights. When i learned flying with my trainer i rarely used the rudder. Now i can't live without it. It will give you more control of the plane, you will be able to do smooth turns, and help you in crosswind landings. If you get a sport/3d plane, then you will have loads of uses to the rudder, cause a lot of maneuvers uses the rudder. Ohh... and you will never be able to make a knife edge without the rudder