Originally Posted by
zkzkz
"dangerously close" can't possibly be the correct phrase. What danger does being over a kilometer from a plane pose?
Depends very much upon which directions the separation requirements were violated.
The danger is that at cruise speeds, any deviation from the flight path, whether due to navigational system drift, pilot commanded turn or some unexpected event, can result in a collision within seconds if two planes just happen to be where they aren't supposed to be.