Joystick
The joystick is based on the design found at "LEGO On My Mind". My version is basically a minaturized version of this design, and I doubt if it can be simplified much further, but I'd love to hear of any design that does. You can download my design in MLCAD format.
The trick with the joystick is to decouple to forward/backward motion from the sideways motion. I messed around for ages trying to this, such simple problems can quickly turn into frustrating nightmares!! Whilst the instructions for my version are available here, I suggest you have a look at this original design as it shows more clearly the concepts used. The key is to make sure that the overall gear ratios on each side are 1:1, and that one side has an even number of turns, and the other side an odd number of turns, it's then a simple matter to decouple the motions using a differential gear. The joystick is towards the centre-right of the picture of the cockpit, the rudder pedals can be seen towards the top.