I assume by "aircraft file" you mean the aircraft.cfg file? In that case, the other two files are "Tigercat v2.air" and "Tigercat v2.aam1.air". Go to the Tigercat file in your FS2004 folder, and you should see a "Tigercat v2.air" file in that folder. Rename it to "Tigercat v2.old.air" or something to that effect, and then extract the "Tigercat v2.air" in the zip file to that folder. You should be all set after that. I can't remember what that "aam1" file was for, but it doesn't seem to be anything of consequence. The aircraft.cfg file and the .air file I detailed above are all you need for it.
