The latest version of Airport is 2.95 and you can get it here:
http://www.airportforwindows.com/downloads.htmlIt should work fine for FS2004, the only issue is mentioned in the quote below from Martin Wright.
"The only change seems to be a reduced support for 8 bit extended Bmps. The transparency in these images does not seem to be as fully supported as before and Textures may require converting to one of the newer Alpha type formats to function correctly."