Ikki,
For adding AI traffic to your simulation, you will want to download and become familiar with the following:
1. AFCAD
2. Traffic Tools by Lee Swordy
3. A Traffic Editing Program - there are many choices, some of which come with Traffic Tools included. I use AI Traffic Mover.
Project AI has some resources that you will find useful (how "useful" depends on how serious you are about realism) including airline installer packages:
http://projectai.flight1.net/That should get you started...........
Good luck
