$FG ROOT

The environment variable $FG_ROOT is a setting referring to the path of the main data directory of FlightGear, which contains the so called base package, also known as FGData. This setting can also be set from the FlightGear Qt launcher, or the command-line. The base package consists of the default aircraft and scenery, GUI files, sounds, 3D models etc.

To set $FG_ROOT from the Qt launcher, click ••• at the top left of the launcher to get the drop down menu and click on Select data files location...

When running FlightGear from a command line, you can set $FG_ROOT via --fg-root=path/to/root. In FGRun, it is set on the paths page, previous to the aircraft selection page.

As of FlightGear 2.4, it is advised to install additional scenery and aircraft in $FG_SCENERY and $FG_AIRCRAFT directories outside $FG_ROOT. This allow for maintaining the additional stuff when installing a new version of FlightGear.

Common paths

• Mac OS X: Applications/FlightGear.app/Contents/Resources/data/ (right-click on FlightGear.app and select "Show Package Contents" to see the Contents folder)

$FG_ROOT is not installed automatically. See New to FlightGear for an installation manual.

• Ubuntu: /usr/share/games/flightgear/
• Windows: Program Files\FlightGear 2020.3\data\ (default, see note!)

Note  Newer Windows versions are very, very protective about the Program Files folder. Installing FlightGear into this folder makes it prone to any problems relating to file read/write permissions. Hence, installing FlightGear into Program Files on Windows Vista and later is not recommended. (I have yet to see where installing it outside of the default location actually helps - jaxsin)

$FG_DATA

You will sometimes see $FG_ROOT erroneously being mentioned as $FG_DATA. While there is no $FG_DATA environment variable, the SourceForge repository containing the base package is named FGData and was earlier named fgdata in Gitorious.