Oceanic procedures question... again

[CaptainLars 21]

Hi,

NATs westbound are active from 1100z to 1930z, if I'm not mistaken, and eastbound from 0100z to 0800z, relative to 30°W. Well, I have two questions concerning this.

1) "Relative to 30°W means that an aircraft's last opportunity to cross 30°W would be 0800z eastbound and 1930z westbound, respectively?

2) Outside of the time during which the NATs are valid, do they function as a random track? Could you use, say, track T westbound in the time between 0800z and 0100z as being on a random track, or at least between approx. 1000z and 2300z, when there wouldn't be any NAT-traffic expected? Otherwise you would have to make a long way around when you want to go westbound during the day (e. g. from the Iberian peninsula to the east coast).

In other words, into what exactly transforms a NAT when the "NAT time" ends for this day and direction?

[scandinavian13 5,192]

13 minutes ago, CaptainLars said:

1) "Relative to 30°W means that an aircraft's last opportunity to cross 30°W would be 0800z eastbound and 1930z westbound, respectively?

Yep. This is my understanding.

14 minutes ago, CaptainLars said:

2) Outside of the time during which the NATs are valid, do they function as a random track? Could you use, say, track T westbound in the time between 0800z and 0100z as being on a random track, or at least between approx. 1000z and 2300z, when there wouldn't be any NAT-traffic expected? Otherwise you would have to make a long way around when you want to go westbound during the day (e. g. from the Iberian peninsula to the east coast).

No. Keep in mind that the tracks include ALL altitudes in a given direction - there's no east/west separation based on odd/even altitudes here. If you're not going in the same direction as the active tracks, you route out to the North or South.

As soon as the track expires, it expires and cannot be used.

[iwebber 207]

14 minutes ago, scandinavian13 said:

As soon as the track expires, it expires and cannot be used.

Kyle is, of course, correct but...

Using an expired westbound track to go west on is not uncommon (and east on an expired eastbound track). Officially you're on a random route but that route can be an original westbound NAT. I used to regularly cross westbound after hours and we usually went on an expired NAT.

Don't forget the westbound and eastbound tracks are usually quite different, the westbound being routed to avoid the headwinds and the eastbound to take advantage of the tailwinds. That's the main reason you wouldn't *want* to go west on an eastbound track, even if they would let you (which they wouldn't).

You don't have to use a NAT, I just came back from a LON NYC trip and we were only on a NAT on the way home, on the way out it was a random route just to the north of the NATs, the company decided it didn't like the NATs published that day and sent us a different route. Your Iberian to East Coast example would probably go on a random route most days, the NATs are really for the bulk of the traffic that passes over France/UK on it's way over, everyone else just makes up their own routing.

Hope this helps,

Ian

[downscc 1,327]

Full names in the PMDG forums please Ian.

Terminology.  Nothing wrong with filing a "expired" track using the same waypoints as long as it doesn't conflict with the now-active tracks, but you are copying the route and it does become a random route.  The bulk of random routes I believe are cargo or military flights, which tend to fly opposite pax flights on the clock.

[Budbud 227]

Hi,

My understanding is that out of the hours of service of Eastbound/Westbound NAT Tracks, you can plan whatever random route you like with the conditions that this route doesn't go nowhere nearer than 1 degree of any active track and doesn't cross any active track.
So you can take an old NAT track, convert it as a random route if it meet the conditions above and you cannot name it NATx in your flight plan as it no longer exists.

[scandinavian13 5,192]

41 minutes ago, Budbud said:

So you can take an old NAT track, convert it as a random route if it meet the conditions above and you cannot name it NATx in your flight plan as it no longer exists.

That's mainly what I was getting at earlier, though I wasn't as clear as I should've been. You need to be out of the way of the stampede and can't list the NAT by name.

[Budbud 227]

6 minutes ago, scandinavian13 said:

That's mainly what I was getting at earlier, though I wasn't as clear as I should've been.

Well yes you were. Actually I have just read again the whole thread and don't understand anymore why I posted here (useless)... 

[CaptainLars 21]

Thank you all for your replies.

 

5 hours ago, scandinavian13 said:

That's mainly what I was getting at earlier, though I wasn't as clear as I should've been. You need to be out of the way of the stampede and can't list the NAT by name.

I'm sorry, I did understand you the way that the track-track (no pun intended) is forbidden after the NAT expires, i. e., not only the NAT expires, but it would be prohibited from that time on to use the space previously occupied by the NAT... I don't know if I explained myself.

So, it is possible to use a previous NAT by programming / filing it as a series of waypoints without naming it like the expired NAT. The restriction is that it has to stay away at least 1° of latitude from an active NAT. Also, adverse meteorological conditions (jetstream) likely render this track a very uneconomic route. But it is possible, and winds are not always that adverse to justify a longer tour around.

So, I hope I understood it correctly...

[Budbud 227]

8 hours ago, CaptainLars said:

So, I hope I understood it correctly...

Yes! ;)

[scandinavian13 5,192]

12 hours ago, CaptainLars said:

So, I hope I understood it correctly...

Yep.

[CaptainLars 21]

Great!