Hi Morten,
If you want to use the airports/runways data held in my 52-week flightplanner as a basis for your later functionality (finding suitable airports based on runway length and surface) feel free to do that. It came from an open source cache of data that is more recent than FS9s, so although the planner is geared to FS9, that data might be suitable for your purposes. There were errors and omissions in the open source stuff - a lot of which I have corrected myself - but it might still be suitable. The open source data reflectes recent - post-FS9 - changes in ICAO codes, so things like the re-coding that Malaysia and Indonesia have done are reflected in that data.
I also have an algorithm for looking ahead for destinations within a certain number of degrees and at certain ranges (intended to get aicraft home via intermediate airports rather than relying on random airport selection - e.g. using Beijing to get from Geneva to New Zealand along a Great Circle using the Haversine Formula), and a much shorter range version of that approach might be what you need to find a likely destination for a tracked aircraft. Often the destination can be worked out from the following departure.
The flightplanner is over on Flightsim.com, and although the coding won't be of much use, the underlying data may well be.
Good luck with the project, even an old FS9er like me is interested in what comes up!
