Hey Hodo, you need to set up the physics in your datablock. The included vehiclemaps should at least get you moving. Getting a realistic airplane is going to take a bit of work I think. Here is a flying car datablock made by someone in the old forums. This is just a cheetah with no wheels as an example and I had to alter the mounting. There is an included crappy install.txt that I threw together.
As far as an action map, it depends on what you want to do. Something like making "w" increase engine RPM instead of "moveforward" is most likely going to take some engine changes because I believe it is just set to a basic global move. The same move that pushes your player forward.
Either way the physics are not really too good. You can take off from any speed and landing is sort of a crash. Heh.