1 minute ago, scandinavian13 said:

Wheels up times are still in use, but the requirement comes from different spots. Could be a wheels up for congested local airspace, airspace a few ARTCCs/FIRs over, or the oceanic sectors. The latter, though, has been cut down through the use of RLatSM tracks in the NAT region (basically, reduced separation, provided the aircraft is properly equipped, etc.).

Got it. Thanks Kyle!

On 9.3.2017 at 2:18 PM, scandinavian13 said:

If you fly the 777's Tutorial #1.5, you'll be able to see some of the simulated exchange just before entering the oceanic segment (you can simply read through it, as well, if you don't feel like flying the whole thing). When you call up for your clearance, the controller will check the track that you requested to see if there is space still available for you (assuming your earlier "I'm 20 min late in the Pacific" example). If there is, you'll get a clearance. If you're out of sequence, you'll likely get a time condition basically saying you need to cross X before/at/after a set time. In the case of the NAT region, you also specify your "backup" track in your initial clearance request, so that the controller can shift you over there if the primary isn't available (due to a delay, etc.).

With the Pacific, there's a lot more room, and it's slightly less organized than the NAT region, so 20 minutes shouldn't be a showstopper. Either way, the delay is adjusted to in real time (partially the reason we have controllers in the first place, if you think about it - they're there to adjust to things in real time and tactically address changes). The plan originally filed was filed for a set time. A delay was incurred, which affected this earlier planned time. When a controller starts working your flight plan, it becomes "active" in the system, and the flight (and now active plan) get a vague ATD (actual time of departure) in the system once you first get snagged on radar (there's a bit more to it than that, but that's for another discussion). That ATD can be used in any traffic management planning, to include checking for route conformance across the procedural segment. Even so, when calling for clearance, the controller will look once more for any conflicts and adjust the timing/routing as appropriate.

That help at all?

So when you file a flightplan inculiding a NAT, you also file a second NAT, in case the first one is not availabe. That was new to me.

That surely helped a lot. Thank you very much.

9 hours ago, CaptainLars said:

So when you file a flightplan inculiding a NAT, you also file a second NAT, in case the first one is not availabe.

File, no. Request clearance prior to entering the NAT, yes (optionally).

If I'm remembering correctly, you tack it in your clearance request after your first NAT request as "...second [TRACK Letter]."

http://ctp.vatsim.net/system/view/includes/Transatlantic_Radio_Operations_Checksheet.pdf

So:

“Request Kennedy Intl. Via NAT ALPHA, second BRAVO, SUNOT 58/20 59/30 59/40 59/50 PRAWN DCT YDP, at flight level 370, mach .82. Estimate SUNOT time 1508 Zulu, TMI 075, SELCAL – CS-AR, BAW123.”