RVSM in the NAT
 

Maybe someone can point me in the right direction. I have seen aircraft pass overhead as well as below our aircraft with a seperation of 1,000' while going in the opposite direction. Since the NAT flow is typically eastbound at night and westbout during the daylight hours I'm trying to put some logic to what is happening during these events. I cannot find anything definitive in the MNPS manuals. Any information is appreciated:ok:

No surprises here, freighter "flow" eastbound is often daylight, so they going opposite the westbound passenger tracks. ATC can, I believe route them "opposing' as long as everyone is RVSM. A bit atypical, perhaps, because the tracks are based on the minimum time route, i.e. most advantageous winds, so usually they are separated by the wind factor. Light winds, etc. might be a factor.

GF

Thanks GFlyer. That's pretty much the way I figured it was working but I can't find a printed data to define the procedure.

You may want to consider "SLOP"

On some NAT routes on the OTS, not all levels are utilized and will be omitted from Track Message. For instance, during daytime, on the westbound flow, you may have Track "Charlie" with available levels 310,320,330,340,360,370,390. So, FL 350 and 380 are available for use by flights on a random routing, which could be opposite the westbound flow. That is why you see opposite direction traffic.

Thanks to all for their replys. Much appreciated.:ok: