What you might be looking for is the Project AI stuff. I and many others use it.

Here is the site:  http://projectai.com

First, click on the link "Official Files" : and get the PAI Installer programs. This installs the packages you download, makes it very simple.

Then, go and get any and as many of the packages from the "Airlines" and/or "Cargo" links displayed below the Installer download link. Bear in mind, the more traffic you put in the air, the more it can slow down you flight sim in FPS. However, many of us have installed quite a bit of Airlines, including myself, with very very little hit on fps.

Hope this is what you were looking for and have fun.