Fgrun is a graphical front end for FlightGear. The airport's list doesn't seem to appear (or ever worse, it dissappears) when the refresh button is pressed. To (re)build this list execute the following line once the FlightGear-data is installed: zcat /usr/share/FlightGear/Airports/metar.dat.gz > \ ${HOME}/.fltk/flightgear.org/fgrun/airports.txt