When is "mid-tier" air combat

When do I get to mid-tier in air battles and what is the experience like in mid-tier for the USSR Air Tech tree

“Mid tier” is a kind of nebulous term. I consider it to be ranks 3-5.

mid tier as i understand is the bit of the game where people give up on war thunder (post ww2 vehicles, so starting rank 5 just about)

Ahh thank you

Mid-tier is usually the BRs/ranks where late WWII vehicles and early Cold War vehicles are seen the most, with the start of jets (imo, at least) being the start of high tier

I would say rank 4-5