Are you intending to say a plane can't be seen at a distance further than 2100 yards?
Walk outside, look up.
No I'm not saying that. You can see a plane miles and miles away, but you don't have an icon above it giving you the exact (give or take 100-200 yard) distance of the enemy. Some pilots don't like it that they can't see enemy wirbles or GVs until 1200 yards or so. And they definitely don't like being 'baited' over enemy wirbles when chasing a target, then getting shot down. So I thought that lowering the enemy icon distance in a GV to 2k or 3k (as suggested by Lunatic1) and then add another idea that has been tossed around of also while in a GV friendly icon range is shortened to 3k as well (for friendly aircraft). I would keep it at 6k for friendly GVs otherwise we will have friendlies killshotting themselves .
I play with all the tools, land, sea air, guns etc. Viewing this from all the perspectives, I found this to be the most balancing answer (in my opinion). It doesn't give any one side an advantage, and makes it harder to kill a plane while in a wirble. If you know how to aim, this will not change how many kills or deaths you get.