I'm just wondering if there are any good airport photo sites that you know of. I'm working on KDSM (Des Moines International Airport) I have been using http://www.airliners.net/ for a few hangars, but it's not enough, and I don't have access to the airport.
While I don't have any advice on where to get good airport photos I encourage you to take a look at Forest - FSX / P3D Tree Placement Tool available here. It's a new graphical utility to help airport scenery designers quickly place vegetation according to real-world location for the region within about a 10km radius around an airport.
www.bing.com/maps has 45° angle maps that you can rotate, so you can see the side of airport buildings. You have to select "bird's eye" at the top of the screen and zoom into the airport to get the 45° angle.
you can try jetphotos.net. If you're really struggling like I am then sifting through social media sites like Facebook, Instagram, Flickr has found me treasures too. Although you have to sift through a whole bunch of selfies and food shots. Small airports then to be much easier on social media sites as there are fewer photos of people inside the terminal which usually isn't that helpful for modelling the outside of an airport.