What kind of controller is needed for this game? All i have is a regular game pad.

I would highly recommend a joystick - the one I have (Logitech Extreme 3D Pro) is a nice stick with a lot of buttons for pretty cheap (<= $30). So if you are interested in playing this and other flight/space sims, such a joystick is a really good deal.

Maybe someone here has played via a gamepad and can tell you about it (although I am not sure depending on gamepad type if it would even work with the game - but I'm not knowledgeable enough to say for certainty). However, regardless of compatibility with other controller types, with this game in particular, I would recommend a joystick.

You get what you put into it.

Assuming either a 360 or PS3 controller-style gamepad: Triggers are your throttle (or rudders), primary stick are your ailerons and elevators. You won't be playing with all the realism settings on, but you can still have a lot of fun.

Personally, I have a Saitek ST290 I got for cheap a few years back, and I love it. It is your basic joystick with a POV hat, twisting joystick, and throttle. It serves me well for everything from Freespace to IL-2 to Mechwarrior to the X-series (honestly, I think my 360 gamepad may be better for the X's, but whatever. I like my ST290 :p). I sometimes have trouble and need to use the keyboard for a lot of features, but it works.

Then you have people who buy expensive flight systems. They are insane, but probably have a hell of a lot of fun.

My suggestion: Stick with the gamepad for now. If you want more, upgrade. Most modern games are made with the 360/PS3-style gamepad in mind, so the joystick will be for sims and older games.