If you publish through an AIAA journal, the default licence assigns copyright to them, but there is an option to select that you retain copyright but just give them permission to reproduce. That's certainly the box I tick, but not everybody notices it, and they certainly don't go out of their way to point it out.
The other thing that a lot of academic authors do now is publish the final drafts (so all the words are in the right order, but the formatting isn't there) on their institution research archives. If you know which university they are from, look on the university website or try searching by paper title on Google Scholar, which should normally index all the open access archives.
That said, these archives can be a bit slow and sometimes take a few months to upload the papers.
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