[freebeard]

Originally Posted by aerohead

If so,you'll notice that there are actually highways in the sky that aircraft fly.
Depending on whether you're flying east-west,or north-south,there are established flight rules pilots must follow in order to maintain safe separation distances.You fly at odd or even altitudes above ground level.I think 500-feet is the minimum vertical separation.
There are classifications for different flight spaces,like Class-A,Class-B,Military,etc..
The FAA is trying to prevent mid-air collisions,as well as protect planes from wingtip vortices,which can send light aircraft into the ground.

I was thinking of these ones:
http://cosmicconvergence.org/wp-cont...1-1024x609.png
from DDG, not endorsing the web site
Maybe they're Photoshopped.