For many years, I've been interested in getting hold of a good airline simulation/game. This would be one that represented the best of simulations - that is, it was both realistic and playable. "Realistic" in this context would mean that it would be possible to reconfigure details such as pricing structure and cabin fittings, operate routes, acquire a reputation, operate a variety of different sorts of airlines to a variety of different destinations. Your opponents ought to correspond in some measure to real airlines. "Playable" would mean that you can set up routes, schedules, aircraft and staff fairly easily.
Airline Tycoon was the most commercially accessible option. However, realism was written down in this for playability. You can have fun buying charter flights and writing programmes for your airliners, but they are too expensive to set up an interesting airline, and as soon as you start doing well, your AI opponents start putting bombs in your aircraft.
Then there was "Airlines 2". This was more realistic from the point of view of the business simulation (though aircraft seem to crash with surprising regularity). But the real problem was that even with the largest airport, you could only schedule five routes with your airline. Hardly a hub in any sense of the word ....
I don't know whether Airline was derived from this or not. I had high hopes of this - it certainly comes with vast amounts of data, and promised a range of options for configuration, and the best timetabling options for flights that I have seen. However, it takes about 15 minutes to start up, and 10 minutes to process quarterly actions. The menu system for moving around it is completely not intuitive. I've tried it, and I stuck with it as it migrated from version 5 to version 6, but whilst conceptually it was great, in terms of its implementation it was (in my opinion) unplayable.
There's a new kid on the block - Airpro. I'm going to go and investigate it now. But if anybody else knows of airline simulations which meet both the playability and realism criteria, then do let me know.