In article 5Z2zg.84642$ZW3.6823@dukeread04,
"Jim Macklin" wrote:

ATC has a box around each IFR airplane, no other airplane
should be in that box. The size of the box changes, but in
general [somebody will surely correct me] is 1,000 above and
below within a distance of from 5 to 20 miles. Anything
closer and it is a near-miss. When you are close enough to
see the individual rivets or make out the color of the other
pilot's eyes, it is also a near-miss.

{I know, loss of separation}


The above posting is not correct. IFR planes have a unique box *only*
against other IFR traffic -- VFR traffic is not mentioned. That is why
you *have* to keep a lookout for traffic when you are under IFR.

An IFR may report a "near miss" when a VFR does not consider it to be a
threat. The "1000 above or below within 5 to 20 miles" applie only to
Class A airspace, *not* to B, C, D, etc.; else traffic flow would
trickle to a halt.