Can't see enemy aircraft

[downtown]

When I fly, I don't see enemy aircraft unless they've fired at me, or they are in red circle range. No grey circles unless they are pursuing an enemy aircraft and firing at it. I find it frustrating that I will be scanning all over the sky, up, down, left, right, forward, backward, and never see anything. I'll be looking back and see tracers appear, then the red circle, than the aircraft.