Is there any program I can run that puts afcads at all the default airports? Or would I have to do that manually? I'm using Marcus Brunner's GATraffic, but to my understanding, it will just put traffic at airports where AFCADS are already installed. So to a large extent, the small airports still have no traffic. Am I correct in this assumption? I'm just looking to get airplanes at every airport throughout the world.Does airport environment upgrade by Chris Arrington add AFCADS at all the airports?

Many small default airports do have traffic parking probably where runways exceed 3,000 feet. I don't know about turf airports.You do not need a separate AFCAD file for a default airport. The elements are in various scenery .bgl files I believe starting with AP followed by a number indicating a cluster of airports in a region.AFCAD will still show these default airports, including small ones that do not contain parking spots. Check your airports of interest and if needed add some parking spots and taxi-route. You may have to add a transparent apron area and use apron type taxi routes which are transparent so aircraft can exit the runway for turf fields with turf parking.An example of an airport with "nothing" but a turf runway is 9Y0 in northern Minnesota. I believe the turf runway is 2,600 feet. You can create an AFCAD adding parking and taxi routes for that which will overlay the default.In the libraries here and on flightsim.com I have often spotted small airport AFCADS and airport scenery that you can download and install. You can search by state or other political region title.