You should download tha PAI files from their website. Each PAI file contains a complete airline: with low polygon aircraft models, aircraft textures, and airline timetable: schedule. They have at least 150 different PAI files.
If you download and install them, you got those airlines flying in the sim. You can create a new BGL file too, that contains only ProjectAI timetables, and it will not screw up your original traffic.bgl. If you download all PAI files you can install them at once

Just open the downloaded multiple PAI files and the installer will extract, split and install them 1 by 1. It takes about 10 or so minutes to install everything in 1 go ! But after it you will surely enjoy the result !
Good luck mate
