"Icebound" wrote in message =
...
=20
So the question is: If my Westbound Cessna at 6000 feet (with the =
autopilot=20
keeping it happily on the GPS-track centerline) meets the descending =
Bonanza=20
on the reciprocal track between the same two airports (using a similar =

GPS/a-p combo), there is a distinct possibility that the horizontal=20
clearance may be zero...


The July 2004 issue of "International Procedures News" from
Flight Safety Inc., carried an item exactly about that,
in regard to the North Atlantic routes.
Here is one paragraph, which I quote from that article:

"Following a successful trial in the West Atlantic Route System (WATRS),
it has been determined that by allowing aircraft conducting oceanic =
flights
to fly lateral offsets not exceeding two NM right of centerline,
an additional safety margin will be provided and will mitigate the risk
of collision when non-normal events such as operational altitude =
deviation errors
and turbulence induced altitude deviations occur."

The remainder of the article describes the 1-nm or 2-nm offsets allowed,
and only to the right of centerline, with effective date of June 10, =
2004.

The name of this concept is "Strategic Lateral Offset Procedure",
so everyone can understand they've now added SLOP to the route system!
As Dave Barry might say, I am not making this up.
---JRC---