How current is the data in FlightGear compared to the real world?
We use the same navaid and airport dataset that X-Plane uses. The current dataset can be found in the $FGROOT/Navaids/ and $FGROOT/Airports/ directories. If you have updates or corrections to the dataset, see http://www.flightgear.org/Docs/AirNav/AptNavFAQ.FlightGear.html for instructions on contacting the database maintainer.