Airpower and helicopter question

[Mustang]

I don't know, but it might be something you are doing that is discouraging the enemy from using their airplanes. Do you usually buy tons of air defence that scares the enemy away? Or do you just move too fast for the AI to call down fire on you?

[Pazam]

I've continued playing around with the settings, and now see that the opponent does purchase aircraft and uses them around turn 4 or so. So one mystery solved!!!

Next mystery - where are enemy helicopters?