Navigating the 777 trans Atlantic/Pacific

[FS737Pilot 12]

Hey folks!

 

Just wondering, how do pilots create flight paths over the ocean? Are there waypoints over the ocean? Or is it more direct? Or less direct?

 

thanks!

[EGLL77W 1,508]

Atlantic Ocean -

 

They have what you call NATS, "North Atlantic Tracks" Updated twice a day. They generally arrange them by weather, there are Westbound & Eastbound tracks. Normally 2 waypoints on each side followed by coordinates. 20W, 30W, 40W & 50W (sometimes 60W-80W for tracks going further across the Atlantic).

 

Westbound are generally even FL's and Eastbound are generally odd FL's. However, special requests are granted. When I flew to LAX we were flying with an AF A388 the whole way, we were FL330 and he was FL340. These requests are made in that kind of situation when you have two on the same track, same position, needing the same FL.

 

You have an assigned Mach number. They're controlled by 4 main centers. 2 on the American/Canadian side and 2 on the European side. Sometimes the tracks go North into Iceland & Greenland Airspace.

 

European ones being:

Shanwick Oceanic EGGX

Santa Maria LPPO

 

US/Canadian ones being:

Gander FIR CZQX

New York Oceanic KZNY

 

Self assigned NAT's are common indeed, these are mainly from flying (e.g.) Heathrow - San Francisco, you'll sometimes go all the way up to 60N+ into Iceland & Greenland's Airspace. Sometimes you get them over the main Atlantic Ocean but not as common.

 

E.g. for a flight plan going from Montreal to London Heathrow -

 

YQB MIILS YYT NATW ELSOX EVRIN UL607 NUMPO UP2 OKESI Y3 BEDEK OCK2F

 

You can see the NAT in there, it's Whiskey! Sometimes the flight plan shows the whole route and not just the NAT letter. Like this one going from Heathrow - Montreal -

 

CPT UL9 KENET UN14 BAKUR PIKIL 57N020W 58N030W 58N040W 56N050W SCROD VALIE FRAZR YRI MIVAX PENTU OMBRE2

 

To get the latest NAT's, weather etc use this - http://blackswan.ch/nat/

 

Now on the Pacific I believe there are tracks, but you only use them for certain routes. They have main Airways that they use so routing is generally similar.

 

If there's anything else you'd like to know or need clearing up let me know!

[FS737Pilot 12]

Atlantic Ocean -

 

They have what you call NATS, "North Atlantic Tracks" Updated twice a day. They generally arrange them by weather, there are Westbound & Eastbound tracks. Normally 2 waypoints on each side followed by coordinates. 20W, 30W, 40W & 50W (sometimes 60W-80W for tracks going further across the Atlantic).

 

Westbound are generally even FL's and Eastbound are generally odd FL's. However, special requests are granted. When I flew to LAX we were flying with an AF A388 the whole way, we were FL330 and he was FL340. These requests are made in that kind of situation when you have two on the same track, same position, needing the same FL.

 

You have an assigned Mach number. They're controlled by 4 main centers. 2 on the American/Canadian side and 2 on the European side. Sometimes the tracks go North into Iceland & Greenland Airspace.

 

European ones being:

Shanwick Oceanic EGGX

Santa Maria LPPO

 

US/Canadian ones being:

Gander FIR CZQX

New York Oceanic KZNY

 

Self assigned NAT's are common indeed, these are mainly from flying (e.g.) Heathrow - San Francisco, you'll sometimes go all the way up to 60N+ into Iceland & Greenland's Airspace. Sometimes you get them over the main Atlantic Ocean but not as common.

 

E.g. for a flight plan going from Montreal to London Heathrow -

 

 

 

YQB MIILS YYT NATW ELSOX EVRIN UL607 NUMPO UP2 OKESI Y3 BEDEK OCK2F

 

You can see the NAT in there, it's Whiskey! Sometimes the flight plan shows the whole route and not just the NAT letter. Like this one going from Heathrow - Montreal -

 

CPT UL9 KENET UN14 BAKUR PIKIL 57N020W 58N030W 58N040W 56N050W SCROD VALIE FRAZR YRI MIVAX PENTU OMBRE2

 

To get the latest NAT's, weather etc use this - http://blackswan.ch/nat/

 

Now on the Pacific I believe there are tracks, but you only use them for certain routes. They have main Airways that they use so routing is generally similar.

 

If there's anything else you'd like to know or need clearing up let me know!

 

Ok so are NATS airways or more like waypoints? In other words, are they paths, or just points to fly to?

[EGLL77W 1,508]

Ok so are NATS airways or more like waypoints? In other words, are they paths, or just points to fly to?

 

Set of waypoints but I guess you can call each NAT a path. All points would be "Direct" in the FMC.

 

Your NAT would depend on the routing after you've crossed.

[scandinavian13 5,192]

Gold Star for not calling them NAT Tracks...

 

The current NATs are posted here in a more official capacity (if it matters):

https://www.notams.faa.gov/common/nat.html

[RomeoMike 10]

Isn't it that twin-engines must often fly more north than the actual NATs in order to stay in the 90min circles of deviation airports?

[Joseph_Van 7]

Isn't it that twin-engines must often fly more north than the actual NATs in order to stay in the 90min circles of deviation airports?

 

E.T.O.P.S you can ben2 hours away from an alternet airport.

[daniel.burke01 1]

E.T.O.P.S you can ben2 hours away from an alternet airport.

 

I even believe now that with the 777 they are or are in the process of extending the ETOPS to 330 minutes...thats a good 5 hours from any point!

 

-Dan Burke-

[DragonNGX 1]

For a flight that is much more southerly across the Atlantic for example the Delta flight from ATL to JNB, do they use something different or are there tracks for more southerly operations.

[GE90110B 1]

I even believe now that with the 777 they are or are in the process of extending the ETOPS to 330 minutes...thats a good 5 hours from any point!

 

-Dan Burke-

 

The entire B777 family is certified by the FAA for ETOPS 240 operations. The -200ER (GE90 only), -200LR, -F, and -300ER are also certified for ETOPS 330.

 

Also you have to consider that aircraft certification is only part of ETOPS operation. The airlines must also be certified for ETOPS operation. I believe that includes certification in areas of maintenance, operations, and of course flight planning.

[EGLL77W 1,508]

For a flight that is much more southerly across the Atlantic for example the Delta flight from ATL to JNB, do they use something different or are there tracks for more southerly operations.

 

Yes Dispatch plan the flight to be within the limits. So they'll pick the best NAT/Airways for the Aircraft & Route.

 

Isn't it that twin-engines must often fly more north than the actual NATs in order to stay in the 90min circles of deviation airports?

 

No the 90 minute ETOPS rule isn't used on the NATs. 180 Minutes is the only legal way you can file for a NAT if it's not going up into Iceland & Greenland Airspace. The 120 Minute rule wouldn't work crossing the Atlantic without going up into Iceland/Greenland.

 

The 330 Minute is for the whole Extended Range 777 fleet with GE engines. I don't believe it's been approved by JAA yet, only FAA last I knew.

 

Gold Star for not calling them NAT Tracks...

 

The current NATs are posted here in a more official capacity (if it matters):

https://www.notams.f...common/nat.html

 

Hehe yeah people call them that a lot!

 

Regarding that website, yeah that's more official but I use the other one also to get the weather & winds. Both can come in handy for sure :P

[mcbellette 145]

I might be wrong, but I think flights between the US and Australia are done via satellite navigation using GPS points that involve the aircraft and satellites communicating by continually updating the aircrafts' position instead of ground-based navaids.

[CaptainTim 0]

Interesting reading although a couple of points I'd like to add.

 

In the NAT Briefing, for each track a number of flight levels will also be issued that can be used for that particular path. Because during the day the majority of the flights are westbound, most or all of the flight levels between FL300 and FL400 can be used. The same principle works at night where most flights are eastbound and again most if not all flight levels are available to use on the track. For the NAT there is no general odd or even flight levels as in most of the RVSM world.

 

For the pacific, PACOTS/OTS routes are generated. Again same principle that tracks are made up of several waypoints that take advantage of winds whether its to take advantage of a tail wind or to avoid a 100 knt headwind.

 

PACOTS - https://pilotweb.nas.faa.gov/PilotWeb/noticesAction.do?queryType=PACIFICTRACKS&formatType=ICAO

 

 

Cheers,

 

Tim

[Joseph_Van 7]

What about Trans Polar routes

[G.Franco Corrias 0]

Have a look at NAT v.4 avaible at AVSIM.

Gianfranco