So, after 2 weeks, I finally received authorization for Fly Away. I'd pretty much given up on them. Anyway, I downloaded the F-15 for my kids. But, I have to say, the installation is really bad. I did what it said in the very funky readme.txt file, but, I still don't even see the plane under my FSx. Why can't they create an actual installation file?
Most people join flyaway for the forums, there are much better download sites out there.
Anyway, most of the downloadable airplanes here were made by people in their free time, and they're not getting paid for it. It's certainly possible to make an installer, but when you're just doing it as a hobby people don't tend to. Adding aircraft to FSX is a bit of a hack to be honest, but the nice thing is that it's pretty much the same procedure for every plane you'll ever add.
http://www.flightsimulationforums.com/viewtopic.php?t=9278 is a great guide with pictures on how to add planes to FSX.
Avsim is a pretty good file library, and free! (Or at least was good, they were hacked and had the entire site taken down a little while back, and are just recently getting back on their feet.)
Hope something here is useful
Thanks, Bob. Actually, and I'm embarrassed to say this, my kids figured this out. I was looking under "missions," but they found it under "free flight."
Thanks for your additional info.