North Atlantic Tracks question
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North Atlantic Tracks question
I recently flew (with Delta) Heathrow - Seattle and return.
On the outward journey, crew announced we are going "way up north today" and our track was over Iceland, Greenland, Northwestern Passages of Canada.
Our return a week later was much further south (south Hudson Bay, south of Greenland etc).
My two questions:
1. Is there a fixed number of North Atlantic tracks available, each one always using the same route/coordinates, or are they more changeable?
2. Was our outward journey unusually far north for this route, or just pretty much bog standard?
Thanx.
On the outward journey, crew announced we are going "way up north today" and our track was over Iceland, Greenland, Northwestern Passages of Canada.
Our return a week later was much further south (south Hudson Bay, south of Greenland etc).
My two questions:
1. Is there a fixed number of North Atlantic tracks available, each one always using the same route/coordinates, or are they more changeable?
2. Was our outward journey unusually far north for this route, or just pretty much bog standard?
Thanx.
TBH the outbound track sounds fairly fairly "bog standard", close to the great circle route (shortest) and it sounds like you weren't on one of the organised Atlantic Tracks.
As to the North Atlantic tracks in general, they change twice a day both to take into account of the fact there's a bit of a "tidal flow" to air traffic over the ocean - most flights go to the States in the European daytime and the other way overnight. Also the jetstream moves, so the published organised tracks also move to either avoid the headwind or make use of the tail wind.
Result is :
1. There are no permanent fixed coordinates over the ocean, we use latitude and longitudes as waypoints and those lat/longs to be overflown are published along with the track identifiers by the authorities (there is a large selection of fixed, named entry and exit points offshore, but not all of those are used every day).
2. The daytime tracks ( westbound to the States) will usually be set up if possible to avoid the usually westerly jetstream, so on the map they may run an unusual distance north or south of what might appear to be the shortest route.
3. At nightime the tracks are eastbound, from the States, and may well be planned to run in the jetstream.
On your way home it's possible you might have been in an official track (possibly the most northern of the nightime eastbound tracks), but it's also possible you were on what is known as a "random" route to the north of the tracks proper.
There's more detail here:
https://en.wikipedia.org/wiki/North_Atlantic_Tracks
As to the North Atlantic tracks in general, they change twice a day both to take into account of the fact there's a bit of a "tidal flow" to air traffic over the ocean - most flights go to the States in the European daytime and the other way overnight. Also the jetstream moves, so the published organised tracks also move to either avoid the headwind or make use of the tail wind.
Result is :
1. There are no permanent fixed coordinates over the ocean, we use latitude and longitudes as waypoints and those lat/longs to be overflown are published along with the track identifiers by the authorities (there is a large selection of fixed, named entry and exit points offshore, but not all of those are used every day).
2. The daytime tracks ( westbound to the States) will usually be set up if possible to avoid the usually westerly jetstream, so on the map they may run an unusual distance north or south of what might appear to be the shortest route.
3. At nightime the tracks are eastbound, from the States, and may well be planned to run in the jetstream.
On your way home it's possible you might have been in an official track (possibly the most northern of the nightime eastbound tracks), but it's also possible you were on what is known as a "random" route to the north of the tracks proper.
There's more detail here:
https://en.wikipedia.org/wiki/North_Atlantic_Tracks
Last edited by wiggy; 30th Nov 2016 at 12:58.
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Many thanx Wiggy for your helpful reply.
Journey out was some 10 hrs and IFE showed a headwind of about 50-70mph if I remember correctly.
However journey back was only 8.75 hours, tailwind of 100+ which was welcomed by all!
Also outward we reached 40,000 or poss higher, but return I don't recall exceeding 35,000 (but of course slept quite a bit!)
Journey out was some 10 hrs and IFE showed a headwind of about 50-70mph if I remember correctly.
However journey back was only 8.75 hours, tailwind of 100+ which was welcomed by all!
Also outward we reached 40,000 or poss higher, but return I don't recall exceeding 35,000 (but of course slept quite a bit!)
You'rer welcome.
It's a fair cop - I've got a really bad habit of posting then having second thoughts or thinking of another way of explaining something ...I promise to try harder first time around...
I've noted your updated/edited info,
My wife had an aunt who emigrated to the US and lived in San Francisco. The routes we took getting there varied pretty well every time. There was a sort of pattern - north from London, just south of Iceland, cross southern Greenland, north of Hudsons Bay cross into the USA somewhere between Winnipeg and Calgary, down to Point Reyes, cross San Francisco city at about 10-12000 feet, down the Peninsular, then reverse course to land up the Bay over the San Mateo bridge to the 28 runways.
A couple stand out. On one occasion we went as far west as Seattle then down the coast and back in September this year we crossed into the USA over the Idaho panhandle down to Point Reyes and then landed on 19R which is almost unheard of according to a BA 747 pilot of my acquaintance.
Coming back has could involve being either north or south of the Great Lakes, I've ended up entering UK airspace over Lands End, Shannon and Southern Scotland. This year coming home our initial cruise was 33000 (I think), then 35000 and finally 39000 - that kind of vertical profile is often related to the weight of the aircraft and as it burns fuel and gets lighter it's able to climb higher. It can also be a way of improving the effect of wind, it's surprising how wind can vary with altitude. In our case I suspect it was a combination of factors with the ability to climb being weight restricted to start with and then as fuel was burned we went higher to take advantage of winds because although the flight from London had arrived 40 minutes late and we took off late as a result we actually arrived in London on time - we got the benefit of the winds that delayed the outbound.
Planning long haul flying is about a balance. That 747 pilot I know also flew 767s long haul for a while. With twins it's not just about fitting in with the weather and great circle (and North Atlantic tracks). There are rules about access to diversionary airfields that need to be taken into account - they have to be predicted to be open as the aircraft passes.
Even short haul has variations. The usual route Paris to London is pretty obvious but on one occasion we headed west then up to Le Havre, Southampton, Heathrow. Geneva usually involved going down to Lyons and turning left but I've also gone over Belgium and Germany.
A couple stand out. On one occasion we went as far west as Seattle then down the coast and back in September this year we crossed into the USA over the Idaho panhandle down to Point Reyes and then landed on 19R which is almost unheard of according to a BA 747 pilot of my acquaintance.
Coming back has could involve being either north or south of the Great Lakes, I've ended up entering UK airspace over Lands End, Shannon and Southern Scotland. This year coming home our initial cruise was 33000 (I think), then 35000 and finally 39000 - that kind of vertical profile is often related to the weight of the aircraft and as it burns fuel and gets lighter it's able to climb higher. It can also be a way of improving the effect of wind, it's surprising how wind can vary with altitude. In our case I suspect it was a combination of factors with the ability to climb being weight restricted to start with and then as fuel was burned we went higher to take advantage of winds because although the flight from London had arrived 40 minutes late and we took off late as a result we actually arrived in London on time - we got the benefit of the winds that delayed the outbound.
Planning long haul flying is about a balance. That 747 pilot I know also flew 767s long haul for a while. With twins it's not just about fitting in with the weather and great circle (and North Atlantic tracks). There are rules about access to diversionary airfields that need to be taken into account - they have to be predicted to be open as the aircraft passes.
Even short haul has variations. The usual route Paris to London is pretty obvious but on one occasion we headed west then up to Le Havre, Southampton, Heathrow. Geneva usually involved going down to Lyons and turning left but I've also gone over Belgium and Germany.
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Thanx for that Hartington. Aircraft weight, possible diversionary airfields etc. all makes perfect sense to me now.
One surprising thing, on the return flight SEA to LHR, the 767 was almost empty. I would say no more than 40 pax, we had so much room to spread out it was like being on our own private jet!
One surprising thing, on the return flight SEA to LHR, the 767 was almost empty. I would say no more than 40 pax, we had so much room to spread out it was like being on our own private jet!
Depends on the upper winds. I did LHR-SEA last week and the jet stream was in the wrong place over southern Iceland pushing us up to 75°N over Thule and the north magnetic pole. Furthest north all three of us had ever beeen (around 50 years of long haul experience in the FD). This is significantly off the great circle, which reaches no further north than 67°N.
This ended up with the wonderful experience of the sun setting as we flew north, and rising as we flew south. We also experienced the moon unsetting or rising in the West.
Flying is cool...
This ended up with the wonderful experience of the sun setting as we flew north, and rising as we flew south. We also experienced the moon unsetting or rising in the West.
Flying is cool...
Many (gosh, almost 40) years of flying LHR to California, the westbound is invariably further north than the eastbound. But there are all sorts of oddballs. Even with this experience, I was most surprised on a LHR-Vancouver flight to overfly Edinburgh on the way up. Likewise an LAX back to London which routed over Bangor ME.
LHR to Miami has been the same. Outward via Lands End and overhead Bermuda had followed, by a few months, another westbound way to the north, over Newfoundland and overhead New York City. This latter was on a 767 which may have been downgraded from ETOPS. We still managed an on time arrival.
LHR to Miami has been the same. Outward via Lands End and overhead Bermuda had followed, by a few months, another westbound way to the north, over Newfoundland and overhead New York City. This latter was on a 767 which may have been downgraded from ETOPS. We still managed an on time arrival.
