$FG_HOME is an environment variable representing the path to where user-specific data is stored (not application data). Basically, it is a name for a directory that varies with the operating system and stores information between sessions: configuration/preferences, properties marked with the "user-archive" attribute and aircraft-specific settings (using the data helper class in aircraft.nas).

Common paths

  • Linux: ~/.fgfs/
  • Mac OS X: ~/Library/Application Support/FlightGear (to learn more about viewing hidden folders, see [1])
As all future FlightGear versions will take their preferences from here, it is a good idea to have their access available easily.
Desktop/Finder/Go/Go to Folder is where you need to start.
When given the option, input: ~/Library/Application Support/FlightGear
It is probably a good idea to have '~/Library/Application Support/FlightGear' saved on a Stickies note just in case you forget it.
If you want/need to refer to any of these files frequently, you could make an alias of a file, or the whole folder, and place it somewhere easier to access.
  • Windows: %APPDATA%\flightgear.org\
%APPDATA% is another environment variable that depends on your Windows version. On XP and older, it can be found under C:\Documents and Settings\{username}\Application Data. On Vista and later it can be found under C:\Users\{username}\AppData. The folder is hidden by default; see these instructions to unhide the folder.