You can put any pilot that you want into any plane. The available pilots are found in your main game folder's objects folder. Their names are:
Just open the particular aircraft's .tmc file in notepad, scroll down to the bottom and you'll see an entry that looks like this:
Change "pilot_pamela" in the C172 for example to "pilot_peter" and you'll now see the pilot from the Jungmeister in the pilot's seat of the C172.
A caveat, however. All of the male pilots have alien mutant hands. Only the female pilots have normal hands. So if you want to sit in the co-pilot's seat and look at the pilot, the males' hands will look a little weird. But if you stay in the pilot's seat, no problem, and it doesn't show on external view.
I'm going to tinker around with the SDK and see if I can create a pilot model in Poser 9 and convert it into Aerofly FS 2. If it works, I can put myself in the various aircraft with my leather flight jacket, silk scarf, and dashing good looks.
I'll report back if I have any luck. It might be a few days. I have to get back up to speed with Poser 9.