North Atlantic Tracks (NATS) & How to Read Them

I have seen quite a few people asking about NATS or talking about them in light of the testers flying across the pond since testing which began sometime back in February. Hopefully this thread will clear some confusion about NATS. I have included a link that gives you updated and most current information about these tracks. At first they will seem like an absolute disaster to decipher. I have included a handy cheat sheet so you can figure out what exactly everything means.

North Atlantic Tracks (NATS)


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This is a very nice post that clears up some confusion about a much-talked about issue. Kudos to you!

What is the “LIMRI” thing to the left of the oceanic exit point?

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Is it just the waypoint before the exit point? @DeerCrusher


@NEO That is correct.

@nicochile2 LIMRI can be seen on this image. Second to last fix before the exit.



What does the list of altitudes mean? Is there a set of distance between the altitude before we can fly to higher altitude level? Is it still possible for pilots to contact the controllers over Ocean to ask for ascend to higher altitude level or does NATS allow us to control our altitude?

Great topic! Bookmarked for later reference.

Could you explain the preferred entry routes? I’m having a hard time trying to figure out what N155A and N141D are.

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Great tutorial, I was just thinking about this today.

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To be honest, I’m not sure what they are. I would assume that it’s an identifier for a route that would be preferred by the controlling agency or airline to the entry position of the NAT. I’m the wrong person to ask since I have never flown on a NATS route. @Heavydriver, @Yuan_Tugo, or @Aernout would be in a better position to answer that.


Thanks for explaining, it’s very helpful indeed :)

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You made a post about something you’ve never done and then when a question pops up its our responsibility? I’m sure @Mark_Denton will make a thorough tutorial when it’s time for this type of information to be released.

FYI it’s not called the NAT anymore!

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They’re the list of altitudes you can cruise at on that track.

He didn’t say it was your responsibility, I think he just wanted to make sure he wasn’t giving out incorrect info and appreciated any help he could get regarding that. I’ve found his post beneficial and informative :)


There’s no benefit or information when data can’t be applied. We can learn all types of things on a daily basis but unless put to use the knowledge becomes faint. Furthermore, FDS puts out tutorials and I’m not one to step on those toes.

Agreed, but I think that’s why he made more of a general post in RWA than a more comprehensive one in #tutorials


Yeah I know that, but my question was what we do with them. Just ascend to an altitude in that list without having to ask controller for permission?

No[quote=“Deaf, post:8, topic:131738”]
Is there a set of distance between the altitude before we can fly to higher altitude level?

Pretty sure you stay at one FL

Not sure

If we have to stay at an altitude then why would we have list of altitudes instead of just one altitude between entry point and exit point.

Well I think heavydriver said that NATS isn’t in use anymore so what is correct procedure for crossing an ocean.

So you can cruise at different altitudes. If I’m flying KJKF-OMDB I’ll want a lower initial altitude as I can’t climb as high as if flying KJFK-EGLL, or just planes with different ceilings

Of course, start at lower altitude and fly higher as you burn enough fuel.