Why would a flight from North America to Asia sometimes fly over the Atlantic?

The name of the pictureThe name of the pictureThe name of the pictureClash Royale CLAN TAG#URR8PPP











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I am going to take AC031 from Toronto to Beijing in a couple of weeks, I searched its flight path, most of the time it will fly westbound after taking off from Toronto and continue west across the north pole area and land in Beijing, but yesterday it flew eastbound, across the Atlantic, this is very strange since the distance is a little bit more than flying westbound.



Why?
flying eastbound



normal flight path







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  • 79




    Very weird definition of "the Atlantic" you have there. It clearly flies over the north pole, not the Atlantic.
    – jwenting
    Aug 1 at 5:49






  • 2




    It's worth noting that only the green segments on the flight path are from actual radar tracking; the white segments are just estimated paths, and are (I believe) just great-circle routes that connect the known positions. So the actual routes for both flights might have been somewhat different.
    – Michael Seifert
    Aug 1 at 15:04







  • 11




    I don't think it's really going east or west much, either way. It flies north, then south :-)
    – jamesqf
    Aug 1 at 15:45






  • 7




    Very weird definition of "clearly" you have there. The problem is the map. Mercator projections are exceptionally poor for anything within a few thousand miles of a pole.
    – Harper
    Aug 2 at 15:46






  • 1




    Spheres are weird.
    – Lightness Races in Orbit
    2 days ago














up vote
34
down vote

favorite
1












I am going to take AC031 from Toronto to Beijing in a couple of weeks, I searched its flight path, most of the time it will fly westbound after taking off from Toronto and continue west across the north pole area and land in Beijing, but yesterday it flew eastbound, across the Atlantic, this is very strange since the distance is a little bit more than flying westbound.



Why?
flying eastbound



normal flight path







share|improve this question

















  • 79




    Very weird definition of "the Atlantic" you have there. It clearly flies over the north pole, not the Atlantic.
    – jwenting
    Aug 1 at 5:49






  • 2




    It's worth noting that only the green segments on the flight path are from actual radar tracking; the white segments are just estimated paths, and are (I believe) just great-circle routes that connect the known positions. So the actual routes for both flights might have been somewhat different.
    – Michael Seifert
    Aug 1 at 15:04







  • 11




    I don't think it's really going east or west much, either way. It flies north, then south :-)
    – jamesqf
    Aug 1 at 15:45






  • 7




    Very weird definition of "clearly" you have there. The problem is the map. Mercator projections are exceptionally poor for anything within a few thousand miles of a pole.
    – Harper
    Aug 2 at 15:46






  • 1




    Spheres are weird.
    – Lightness Races in Orbit
    2 days ago












up vote
34
down vote

favorite
1









up vote
34
down vote

favorite
1






1





I am going to take AC031 from Toronto to Beijing in a couple of weeks, I searched its flight path, most of the time it will fly westbound after taking off from Toronto and continue west across the north pole area and land in Beijing, but yesterday it flew eastbound, across the Atlantic, this is very strange since the distance is a little bit more than flying westbound.



Why?
flying eastbound



normal flight path







share|improve this question













I am going to take AC031 from Toronto to Beijing in a couple of weeks, I searched its flight path, most of the time it will fly westbound after taking off from Toronto and continue west across the north pole area and land in Beijing, but yesterday it flew eastbound, across the Atlantic, this is very strange since the distance is a little bit more than flying westbound.



Why?
flying eastbound



normal flight path









share|improve this question












share|improve this question




share|improve this question








edited Aug 1 at 15:54









FreeMan

6,723650114




6,723650114









asked Aug 1 at 4:12









Yifan Nie

182125




182125







  • 79




    Very weird definition of "the Atlantic" you have there. It clearly flies over the north pole, not the Atlantic.
    – jwenting
    Aug 1 at 5:49






  • 2




    It's worth noting that only the green segments on the flight path are from actual radar tracking; the white segments are just estimated paths, and are (I believe) just great-circle routes that connect the known positions. So the actual routes for both flights might have been somewhat different.
    – Michael Seifert
    Aug 1 at 15:04







  • 11




    I don't think it's really going east or west much, either way. It flies north, then south :-)
    – jamesqf
    Aug 1 at 15:45






  • 7




    Very weird definition of "clearly" you have there. The problem is the map. Mercator projections are exceptionally poor for anything within a few thousand miles of a pole.
    – Harper
    Aug 2 at 15:46






  • 1




    Spheres are weird.
    – Lightness Races in Orbit
    2 days ago












  • 79




    Very weird definition of "the Atlantic" you have there. It clearly flies over the north pole, not the Atlantic.
    – jwenting
    Aug 1 at 5:49






  • 2




    It's worth noting that only the green segments on the flight path are from actual radar tracking; the white segments are just estimated paths, and are (I believe) just great-circle routes that connect the known positions. So the actual routes for both flights might have been somewhat different.
    – Michael Seifert
    Aug 1 at 15:04







  • 11




    I don't think it's really going east or west much, either way. It flies north, then south :-)
    – jamesqf
    Aug 1 at 15:45






  • 7




    Very weird definition of "clearly" you have there. The problem is the map. Mercator projections are exceptionally poor for anything within a few thousand miles of a pole.
    – Harper
    Aug 2 at 15:46






  • 1




    Spheres are weird.
    – Lightness Races in Orbit
    2 days ago







79




79




Very weird definition of "the Atlantic" you have there. It clearly flies over the north pole, not the Atlantic.
– jwenting
Aug 1 at 5:49




Very weird definition of "the Atlantic" you have there. It clearly flies over the north pole, not the Atlantic.
– jwenting
Aug 1 at 5:49




2




2




It's worth noting that only the green segments on the flight path are from actual radar tracking; the white segments are just estimated paths, and are (I believe) just great-circle routes that connect the known positions. So the actual routes for both flights might have been somewhat different.
– Michael Seifert
Aug 1 at 15:04





It's worth noting that only the green segments on the flight path are from actual radar tracking; the white segments are just estimated paths, and are (I believe) just great-circle routes that connect the known positions. So the actual routes for both flights might have been somewhat different.
– Michael Seifert
Aug 1 at 15:04





11




11




I don't think it's really going east or west much, either way. It flies north, then south :-)
– jamesqf
Aug 1 at 15:45




I don't think it's really going east or west much, either way. It flies north, then south :-)
– jamesqf
Aug 1 at 15:45




7




7




Very weird definition of "clearly" you have there. The problem is the map. Mercator projections are exceptionally poor for anything within a few thousand miles of a pole.
– Harper
Aug 2 at 15:46




Very weird definition of "clearly" you have there. The problem is the map. Mercator projections are exceptionally poor for anything within a few thousand miles of a pole.
– Harper
Aug 2 at 15:46




1




1




Spheres are weird.
– Lightness Races in Orbit
2 days ago




Spheres are weird.
– Lightness Races in Orbit
2 days ago










5 Answers
5






active

oldest

votes

















up vote
86
down vote



accepted










Those routes are extremely similar.



They're basically two almost-a-straight-line routes over the arctic ocean, except that the second one has deviated a bit to the right, so that it's gone just on the right of the North Pole instead of passing by the left. At the pole itself, there's no such thing as "East" or "West", and if you pass very close to it, there is a discontinuous jump between passing it "going East" and "going West".



You can see this explicitly by going to FlightAware, asking to View track log, and downloading the flight tracking data to be viewed on Google Earth:





Actual tracking data in white. Interpolations for the missing-data parts in green.



As you can see, there is indeed a nontrivial deviation of what's probably several hundred kilometers in clipping Nunavut vs the northeast corner of Greenland, but that deviation is within the normal ranges of what you'd get in your standard transatlantic flight, say. The only change here is that the variation now includes the North Pole itself.






share|improve this answer

















  • 6




    Credit obviously due to the three answers posted previously to this one, which contain very similar content - I just thought I could provide a slightly clearer version and pull in the actual flight tracks.
    – E.P.
    Aug 1 at 18:10






  • 1




    Unrelated to the OP's question: is it possible one or the other of those (similar) routes is chosen due to eg. airstream etc ??
    – Fattie
    Aug 1 at 18:13






  • 3




    @Fattie There are many factors that go into planning flight paths; wind conditions are obviously one of the most important ones.
    – E.P.
    Aug 1 at 18:34










  • It makes sense when you put it that way @E.P. :)
    – Fattie
    Aug 1 at 18:58










  • Is there any way to overlay the two routes onto the same image?
    – jpmc26
    Aug 3 at 0:19


















up vote
80
down vote













The direct route from YYZ to PEK flies almost over the north pole:



enter image description here



Sometimes, routes need to deviate a bit from the "direct" route, due to prevailing winds or other traffic. If your route from YYZ needs to deviate a bit to the right, then it will cross over to the other side of the north pole (which is the very centre of the map above), and your projected map from Flightaware would show it flying "over" the Atlantic. But really, it's just gone slightly to the right of the pole.






share|improve this answer



















  • 28




    Showing the right picture can make a big difference. +1.
    – Pete Becker
    Aug 1 at 11:22







  • 12




    The aircraft must remain within 180 mins of a suitable landing airports at all times. There are very few airports along that Polar route so weather conditions may dictate a more easterly route over Greenland on some days.
    – Mike Sowsun
    Aug 1 at 11:30










  • The difference between 'east' and 'west' routes is almost always driven by the winds. The 'east' route is more common in the winter due to the stronger jet stream.
    – Gerry
    Aug 1 at 12:12






  • 2




    180 minutes - wouldn't that be about 1500 miles? With airports in Alaska, Iceland, and Norway that doesn't look like it would be too difficult.
    – nasch
    Aug 1 at 15:27






  • 4




    Not sure which is the relevant regulatory body here, but the Boeing 777-300ER has been certified by FAA in the US to fly as far as 330 minutes from airports aviationweek.com/awin/faa-extends-777-etops-approval
    – Roman Odaisky
    Aug 1 at 23:25

















up vote
76
down vote













I took Hewgill's picture and added the routes in the OP (I just eyeballed this, so I won't guarantee accuracy).



Flight paths from over the north pole



With the FlightAware maps it looks like drastically different routes, but from this angle you can see that both routes are not that far off the ideal route.






share|improve this answer

















  • 11




    This is actually the most useful answer as it shows visually how little difference there is between the flight tracks. Not that any of the others are wrong...
    – FreeMan
    Aug 1 at 16:09

















up vote
32
down vote













The flight did not fly across the Atlantic. Rather, you're seeing the results of stereographic projection.



More specifically, the Earth is round. Navigation needs to be thought of on the basis of a sphere. It is 3-dimensional, and if you have studied sphere geometry, you will know that it defies the rules of geometry we know in 2D - for example it is possible to construct a triangle with three 90-degree angles.



The problem is that 3-dimensional objects cannot be displayed on a map, which is 2-dimensional. Therefore a mathematical formula is used to make a sphere look like a rectangle. The conversion is really skewed for regions near the poles. As a result, you cannot compare distances by measuring them on the projected map.



The route merely deviated slightly to the left in the second picture. However it is still flying over the North Pole, not the Atlantic. The deviation may be due to changes in winds aloft and/or traffic.






share|improve this answer



















  • 14




    @Cloud That's a byproduct of the map projection used by FlightAware. The Earth isn't flat, so the shortest distance between two points won't show up as a straight line on that map (the actual shortest distance for flight planning purposes also takes winds into account). The ideal path isn't anything remotely close to a straight line.
    – Zach Lipton
    Aug 1 at 7:13






  • 4




    @Cloud It only looks like a big curve due to the limitations of drawing that type of projection. It isn't nearly as bad as it looks.
    – Mast
    Aug 1 at 8:30







  • 4




    @Cloud This great circle visualization of the ideal route might help you understand. Look at the 3D view to see how the route looks on a globe, then switch to the 2D view with the button in the top right and see how different it looks on a flat map.
    – kwc
    Aug 1 at 9:02






  • 1




    Some years ago, talking with a friend, I did a demonstration with a small ball and a tape measure. (He worked in a custom tailor shop in Bangkok.) The look on his face as he realized that the curved path really meant was PRICELESS.
    – John R. Strohm
    Aug 1 at 17:54






  • 3




    Wait, wait, wait! You mean the earth is ROUND?! So, why would NBA players mislead us?
    – TomMcW
    Aug 1 at 18:14

















up vote
6
down vote













To complement the posted correct answers, consider this page: https://en.wikipedia.org/wiki/Antipodes#Cities



It contains a list of cities that are exactly (or almost exactly) opposite one another on the spherical earth (antipodal); for example, Xi'an, China and Santiago, Chile.



You could leave Santiago, and fly in a straight line (great circle, not a rhumb line) in literally any starting direction and still wind up close to Xi'an.



Of course, range and availability of alternate landing fields along the way would limit your choices...






share|improve this answer




















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    5 Answers
    5






    active

    oldest

    votes








    5 Answers
    5






    active

    oldest

    votes









    active

    oldest

    votes






    active

    oldest

    votes








    up vote
    86
    down vote



    accepted










    Those routes are extremely similar.



    They're basically two almost-a-straight-line routes over the arctic ocean, except that the second one has deviated a bit to the right, so that it's gone just on the right of the North Pole instead of passing by the left. At the pole itself, there's no such thing as "East" or "West", and if you pass very close to it, there is a discontinuous jump between passing it "going East" and "going West".



    You can see this explicitly by going to FlightAware, asking to View track log, and downloading the flight tracking data to be viewed on Google Earth:





    Actual tracking data in white. Interpolations for the missing-data parts in green.



    As you can see, there is indeed a nontrivial deviation of what's probably several hundred kilometers in clipping Nunavut vs the northeast corner of Greenland, but that deviation is within the normal ranges of what you'd get in your standard transatlantic flight, say. The only change here is that the variation now includes the North Pole itself.






    share|improve this answer

















    • 6




      Credit obviously due to the three answers posted previously to this one, which contain very similar content - I just thought I could provide a slightly clearer version and pull in the actual flight tracks.
      – E.P.
      Aug 1 at 18:10






    • 1




      Unrelated to the OP's question: is it possible one or the other of those (similar) routes is chosen due to eg. airstream etc ??
      – Fattie
      Aug 1 at 18:13






    • 3




      @Fattie There are many factors that go into planning flight paths; wind conditions are obviously one of the most important ones.
      – E.P.
      Aug 1 at 18:34










    • It makes sense when you put it that way @E.P. :)
      – Fattie
      Aug 1 at 18:58










    • Is there any way to overlay the two routes onto the same image?
      – jpmc26
      Aug 3 at 0:19















    up vote
    86
    down vote



    accepted










    Those routes are extremely similar.



    They're basically two almost-a-straight-line routes over the arctic ocean, except that the second one has deviated a bit to the right, so that it's gone just on the right of the North Pole instead of passing by the left. At the pole itself, there's no such thing as "East" or "West", and if you pass very close to it, there is a discontinuous jump between passing it "going East" and "going West".



    You can see this explicitly by going to FlightAware, asking to View track log, and downloading the flight tracking data to be viewed on Google Earth:





    Actual tracking data in white. Interpolations for the missing-data parts in green.



    As you can see, there is indeed a nontrivial deviation of what's probably several hundred kilometers in clipping Nunavut vs the northeast corner of Greenland, but that deviation is within the normal ranges of what you'd get in your standard transatlantic flight, say. The only change here is that the variation now includes the North Pole itself.






    share|improve this answer

















    • 6




      Credit obviously due to the three answers posted previously to this one, which contain very similar content - I just thought I could provide a slightly clearer version and pull in the actual flight tracks.
      – E.P.
      Aug 1 at 18:10






    • 1




      Unrelated to the OP's question: is it possible one or the other of those (similar) routes is chosen due to eg. airstream etc ??
      – Fattie
      Aug 1 at 18:13






    • 3




      @Fattie There are many factors that go into planning flight paths; wind conditions are obviously one of the most important ones.
      – E.P.
      Aug 1 at 18:34










    • It makes sense when you put it that way @E.P. :)
      – Fattie
      Aug 1 at 18:58










    • Is there any way to overlay the two routes onto the same image?
      – jpmc26
      Aug 3 at 0:19













    up vote
    86
    down vote



    accepted







    up vote
    86
    down vote



    accepted






    Those routes are extremely similar.



    They're basically two almost-a-straight-line routes over the arctic ocean, except that the second one has deviated a bit to the right, so that it's gone just on the right of the North Pole instead of passing by the left. At the pole itself, there's no such thing as "East" or "West", and if you pass very close to it, there is a discontinuous jump between passing it "going East" and "going West".



    You can see this explicitly by going to FlightAware, asking to View track log, and downloading the flight tracking data to be viewed on Google Earth:





    Actual tracking data in white. Interpolations for the missing-data parts in green.



    As you can see, there is indeed a nontrivial deviation of what's probably several hundred kilometers in clipping Nunavut vs the northeast corner of Greenland, but that deviation is within the normal ranges of what you'd get in your standard transatlantic flight, say. The only change here is that the variation now includes the North Pole itself.






    share|improve this answer













    Those routes are extremely similar.



    They're basically two almost-a-straight-line routes over the arctic ocean, except that the second one has deviated a bit to the right, so that it's gone just on the right of the North Pole instead of passing by the left. At the pole itself, there's no such thing as "East" or "West", and if you pass very close to it, there is a discontinuous jump between passing it "going East" and "going West".



    You can see this explicitly by going to FlightAware, asking to View track log, and downloading the flight tracking data to be viewed on Google Earth:





    Actual tracking data in white. Interpolations for the missing-data parts in green.



    As you can see, there is indeed a nontrivial deviation of what's probably several hundred kilometers in clipping Nunavut vs the northeast corner of Greenland, but that deviation is within the normal ranges of what you'd get in your standard transatlantic flight, say. The only change here is that the variation now includes the North Pole itself.







    share|improve this answer













    share|improve this answer



    share|improve this answer











    answered Aug 1 at 16:06









    E.P.

    944713




    944713







    • 6




      Credit obviously due to the three answers posted previously to this one, which contain very similar content - I just thought I could provide a slightly clearer version and pull in the actual flight tracks.
      – E.P.
      Aug 1 at 18:10






    • 1




      Unrelated to the OP's question: is it possible one or the other of those (similar) routes is chosen due to eg. airstream etc ??
      – Fattie
      Aug 1 at 18:13






    • 3




      @Fattie There are many factors that go into planning flight paths; wind conditions are obviously one of the most important ones.
      – E.P.
      Aug 1 at 18:34










    • It makes sense when you put it that way @E.P. :)
      – Fattie
      Aug 1 at 18:58










    • Is there any way to overlay the two routes onto the same image?
      – jpmc26
      Aug 3 at 0:19













    • 6




      Credit obviously due to the three answers posted previously to this one, which contain very similar content - I just thought I could provide a slightly clearer version and pull in the actual flight tracks.
      – E.P.
      Aug 1 at 18:10






    • 1




      Unrelated to the OP's question: is it possible one or the other of those (similar) routes is chosen due to eg. airstream etc ??
      – Fattie
      Aug 1 at 18:13






    • 3




      @Fattie There are many factors that go into planning flight paths; wind conditions are obviously one of the most important ones.
      – E.P.
      Aug 1 at 18:34










    • It makes sense when you put it that way @E.P. :)
      – Fattie
      Aug 1 at 18:58










    • Is there any way to overlay the two routes onto the same image?
      – jpmc26
      Aug 3 at 0:19








    6




    6




    Credit obviously due to the three answers posted previously to this one, which contain very similar content - I just thought I could provide a slightly clearer version and pull in the actual flight tracks.
    – E.P.
    Aug 1 at 18:10




    Credit obviously due to the three answers posted previously to this one, which contain very similar content - I just thought I could provide a slightly clearer version and pull in the actual flight tracks.
    – E.P.
    Aug 1 at 18:10




    1




    1




    Unrelated to the OP's question: is it possible one or the other of those (similar) routes is chosen due to eg. airstream etc ??
    – Fattie
    Aug 1 at 18:13




    Unrelated to the OP's question: is it possible one or the other of those (similar) routes is chosen due to eg. airstream etc ??
    – Fattie
    Aug 1 at 18:13




    3




    3




    @Fattie There are many factors that go into planning flight paths; wind conditions are obviously one of the most important ones.
    – E.P.
    Aug 1 at 18:34




    @Fattie There are many factors that go into planning flight paths; wind conditions are obviously one of the most important ones.
    – E.P.
    Aug 1 at 18:34












    It makes sense when you put it that way @E.P. :)
    – Fattie
    Aug 1 at 18:58




    It makes sense when you put it that way @E.P. :)
    – Fattie
    Aug 1 at 18:58












    Is there any way to overlay the two routes onto the same image?
    – jpmc26
    Aug 3 at 0:19





    Is there any way to overlay the two routes onto the same image?
    – jpmc26
    Aug 3 at 0:19











    up vote
    80
    down vote













    The direct route from YYZ to PEK flies almost over the north pole:



    enter image description here



    Sometimes, routes need to deviate a bit from the "direct" route, due to prevailing winds or other traffic. If your route from YYZ needs to deviate a bit to the right, then it will cross over to the other side of the north pole (which is the very centre of the map above), and your projected map from Flightaware would show it flying "over" the Atlantic. But really, it's just gone slightly to the right of the pole.






    share|improve this answer



















    • 28




      Showing the right picture can make a big difference. +1.
      – Pete Becker
      Aug 1 at 11:22







    • 12




      The aircraft must remain within 180 mins of a suitable landing airports at all times. There are very few airports along that Polar route so weather conditions may dictate a more easterly route over Greenland on some days.
      – Mike Sowsun
      Aug 1 at 11:30










    • The difference between 'east' and 'west' routes is almost always driven by the winds. The 'east' route is more common in the winter due to the stronger jet stream.
      – Gerry
      Aug 1 at 12:12






    • 2




      180 minutes - wouldn't that be about 1500 miles? With airports in Alaska, Iceland, and Norway that doesn't look like it would be too difficult.
      – nasch
      Aug 1 at 15:27






    • 4




      Not sure which is the relevant regulatory body here, but the Boeing 777-300ER has been certified by FAA in the US to fly as far as 330 minutes from airports aviationweek.com/awin/faa-extends-777-etops-approval
      – Roman Odaisky
      Aug 1 at 23:25














    up vote
    80
    down vote













    The direct route from YYZ to PEK flies almost over the north pole:



    enter image description here



    Sometimes, routes need to deviate a bit from the "direct" route, due to prevailing winds or other traffic. If your route from YYZ needs to deviate a bit to the right, then it will cross over to the other side of the north pole (which is the very centre of the map above), and your projected map from Flightaware would show it flying "over" the Atlantic. But really, it's just gone slightly to the right of the pole.






    share|improve this answer



















    • 28




      Showing the right picture can make a big difference. +1.
      – Pete Becker
      Aug 1 at 11:22







    • 12




      The aircraft must remain within 180 mins of a suitable landing airports at all times. There are very few airports along that Polar route so weather conditions may dictate a more easterly route over Greenland on some days.
      – Mike Sowsun
      Aug 1 at 11:30










    • The difference between 'east' and 'west' routes is almost always driven by the winds. The 'east' route is more common in the winter due to the stronger jet stream.
      – Gerry
      Aug 1 at 12:12






    • 2




      180 minutes - wouldn't that be about 1500 miles? With airports in Alaska, Iceland, and Norway that doesn't look like it would be too difficult.
      – nasch
      Aug 1 at 15:27






    • 4




      Not sure which is the relevant regulatory body here, but the Boeing 777-300ER has been certified by FAA in the US to fly as far as 330 minutes from airports aviationweek.com/awin/faa-extends-777-etops-approval
      – Roman Odaisky
      Aug 1 at 23:25












    up vote
    80
    down vote










    up vote
    80
    down vote









    The direct route from YYZ to PEK flies almost over the north pole:



    enter image description here



    Sometimes, routes need to deviate a bit from the "direct" route, due to prevailing winds or other traffic. If your route from YYZ needs to deviate a bit to the right, then it will cross over to the other side of the north pole (which is the very centre of the map above), and your projected map from Flightaware would show it flying "over" the Atlantic. But really, it's just gone slightly to the right of the pole.






    share|improve this answer















    The direct route from YYZ to PEK flies almost over the north pole:



    enter image description here



    Sometimes, routes need to deviate a bit from the "direct" route, due to prevailing winds or other traffic. If your route from YYZ needs to deviate a bit to the right, then it will cross over to the other side of the north pole (which is the very centre of the map above), and your projected map from Flightaware would show it flying "over" the Atlantic. But really, it's just gone slightly to the right of the pole.







    share|improve this answer















    share|improve this answer



    share|improve this answer








    edited Aug 2 at 12:45









    jcaron

    437311




    437311











    answered Aug 1 at 5:01









    Greg Hewgill

    6,11612432




    6,11612432







    • 28




      Showing the right picture can make a big difference. +1.
      – Pete Becker
      Aug 1 at 11:22







    • 12




      The aircraft must remain within 180 mins of a suitable landing airports at all times. There are very few airports along that Polar route so weather conditions may dictate a more easterly route over Greenland on some days.
      – Mike Sowsun
      Aug 1 at 11:30










    • The difference between 'east' and 'west' routes is almost always driven by the winds. The 'east' route is more common in the winter due to the stronger jet stream.
      – Gerry
      Aug 1 at 12:12






    • 2




      180 minutes - wouldn't that be about 1500 miles? With airports in Alaska, Iceland, and Norway that doesn't look like it would be too difficult.
      – nasch
      Aug 1 at 15:27






    • 4




      Not sure which is the relevant regulatory body here, but the Boeing 777-300ER has been certified by FAA in the US to fly as far as 330 minutes from airports aviationweek.com/awin/faa-extends-777-etops-approval
      – Roman Odaisky
      Aug 1 at 23:25












    • 28




      Showing the right picture can make a big difference. +1.
      – Pete Becker
      Aug 1 at 11:22







    • 12




      The aircraft must remain within 180 mins of a suitable landing airports at all times. There are very few airports along that Polar route so weather conditions may dictate a more easterly route over Greenland on some days.
      – Mike Sowsun
      Aug 1 at 11:30










    • The difference between 'east' and 'west' routes is almost always driven by the winds. The 'east' route is more common in the winter due to the stronger jet stream.
      – Gerry
      Aug 1 at 12:12






    • 2




      180 minutes - wouldn't that be about 1500 miles? With airports in Alaska, Iceland, and Norway that doesn't look like it would be too difficult.
      – nasch
      Aug 1 at 15:27






    • 4




      Not sure which is the relevant regulatory body here, but the Boeing 777-300ER has been certified by FAA in the US to fly as far as 330 minutes from airports aviationweek.com/awin/faa-extends-777-etops-approval
      – Roman Odaisky
      Aug 1 at 23:25







    28




    28




    Showing the right picture can make a big difference. +1.
    – Pete Becker
    Aug 1 at 11:22





    Showing the right picture can make a big difference. +1.
    – Pete Becker
    Aug 1 at 11:22





    12




    12




    The aircraft must remain within 180 mins of a suitable landing airports at all times. There are very few airports along that Polar route so weather conditions may dictate a more easterly route over Greenland on some days.
    – Mike Sowsun
    Aug 1 at 11:30




    The aircraft must remain within 180 mins of a suitable landing airports at all times. There are very few airports along that Polar route so weather conditions may dictate a more easterly route over Greenland on some days.
    – Mike Sowsun
    Aug 1 at 11:30












    The difference between 'east' and 'west' routes is almost always driven by the winds. The 'east' route is more common in the winter due to the stronger jet stream.
    – Gerry
    Aug 1 at 12:12




    The difference between 'east' and 'west' routes is almost always driven by the winds. The 'east' route is more common in the winter due to the stronger jet stream.
    – Gerry
    Aug 1 at 12:12




    2




    2




    180 minutes - wouldn't that be about 1500 miles? With airports in Alaska, Iceland, and Norway that doesn't look like it would be too difficult.
    – nasch
    Aug 1 at 15:27




    180 minutes - wouldn't that be about 1500 miles? With airports in Alaska, Iceland, and Norway that doesn't look like it would be too difficult.
    – nasch
    Aug 1 at 15:27




    4




    4




    Not sure which is the relevant regulatory body here, but the Boeing 777-300ER has been certified by FAA in the US to fly as far as 330 minutes from airports aviationweek.com/awin/faa-extends-777-etops-approval
    – Roman Odaisky
    Aug 1 at 23:25




    Not sure which is the relevant regulatory body here, but the Boeing 777-300ER has been certified by FAA in the US to fly as far as 330 minutes from airports aviationweek.com/awin/faa-extends-777-etops-approval
    – Roman Odaisky
    Aug 1 at 23:25










    up vote
    76
    down vote













    I took Hewgill's picture and added the routes in the OP (I just eyeballed this, so I won't guarantee accuracy).



    Flight paths from over the north pole



    With the FlightAware maps it looks like drastically different routes, but from this angle you can see that both routes are not that far off the ideal route.






    share|improve this answer

















    • 11




      This is actually the most useful answer as it shows visually how little difference there is between the flight tracks. Not that any of the others are wrong...
      – FreeMan
      Aug 1 at 16:09














    up vote
    76
    down vote













    I took Hewgill's picture and added the routes in the OP (I just eyeballed this, so I won't guarantee accuracy).



    Flight paths from over the north pole



    With the FlightAware maps it looks like drastically different routes, but from this angle you can see that both routes are not that far off the ideal route.






    share|improve this answer

















    • 11




      This is actually the most useful answer as it shows visually how little difference there is between the flight tracks. Not that any of the others are wrong...
      – FreeMan
      Aug 1 at 16:09












    up vote
    76
    down vote










    up vote
    76
    down vote









    I took Hewgill's picture and added the routes in the OP (I just eyeballed this, so I won't guarantee accuracy).



    Flight paths from over the north pole



    With the FlightAware maps it looks like drastically different routes, but from this angle you can see that both routes are not that far off the ideal route.






    share|improve this answer













    I took Hewgill's picture and added the routes in the OP (I just eyeballed this, so I won't guarantee accuracy).



    Flight paths from over the north pole



    With the FlightAware maps it looks like drastically different routes, but from this angle you can see that both routes are not that far off the ideal route.







    share|improve this answer













    share|improve this answer



    share|improve this answer











    answered Aug 1 at 14:21









    Eugene Styer

    1,311510




    1,311510







    • 11




      This is actually the most useful answer as it shows visually how little difference there is between the flight tracks. Not that any of the others are wrong...
      – FreeMan
      Aug 1 at 16:09












    • 11




      This is actually the most useful answer as it shows visually how little difference there is between the flight tracks. Not that any of the others are wrong...
      – FreeMan
      Aug 1 at 16:09







    11




    11




    This is actually the most useful answer as it shows visually how little difference there is between the flight tracks. Not that any of the others are wrong...
    – FreeMan
    Aug 1 at 16:09




    This is actually the most useful answer as it shows visually how little difference there is between the flight tracks. Not that any of the others are wrong...
    – FreeMan
    Aug 1 at 16:09










    up vote
    32
    down vote













    The flight did not fly across the Atlantic. Rather, you're seeing the results of stereographic projection.



    More specifically, the Earth is round. Navigation needs to be thought of on the basis of a sphere. It is 3-dimensional, and if you have studied sphere geometry, you will know that it defies the rules of geometry we know in 2D - for example it is possible to construct a triangle with three 90-degree angles.



    The problem is that 3-dimensional objects cannot be displayed on a map, which is 2-dimensional. Therefore a mathematical formula is used to make a sphere look like a rectangle. The conversion is really skewed for regions near the poles. As a result, you cannot compare distances by measuring them on the projected map.



    The route merely deviated slightly to the left in the second picture. However it is still flying over the North Pole, not the Atlantic. The deviation may be due to changes in winds aloft and/or traffic.






    share|improve this answer



















    • 14




      @Cloud That's a byproduct of the map projection used by FlightAware. The Earth isn't flat, so the shortest distance between two points won't show up as a straight line on that map (the actual shortest distance for flight planning purposes also takes winds into account). The ideal path isn't anything remotely close to a straight line.
      – Zach Lipton
      Aug 1 at 7:13






    • 4




      @Cloud It only looks like a big curve due to the limitations of drawing that type of projection. It isn't nearly as bad as it looks.
      – Mast
      Aug 1 at 8:30







    • 4




      @Cloud This great circle visualization of the ideal route might help you understand. Look at the 3D view to see how the route looks on a globe, then switch to the 2D view with the button in the top right and see how different it looks on a flat map.
      – kwc
      Aug 1 at 9:02






    • 1




      Some years ago, talking with a friend, I did a demonstration with a small ball and a tape measure. (He worked in a custom tailor shop in Bangkok.) The look on his face as he realized that the curved path really meant was PRICELESS.
      – John R. Strohm
      Aug 1 at 17:54






    • 3




      Wait, wait, wait! You mean the earth is ROUND?! So, why would NBA players mislead us?
      – TomMcW
      Aug 1 at 18:14














    up vote
    32
    down vote













    The flight did not fly across the Atlantic. Rather, you're seeing the results of stereographic projection.



    More specifically, the Earth is round. Navigation needs to be thought of on the basis of a sphere. It is 3-dimensional, and if you have studied sphere geometry, you will know that it defies the rules of geometry we know in 2D - for example it is possible to construct a triangle with three 90-degree angles.



    The problem is that 3-dimensional objects cannot be displayed on a map, which is 2-dimensional. Therefore a mathematical formula is used to make a sphere look like a rectangle. The conversion is really skewed for regions near the poles. As a result, you cannot compare distances by measuring them on the projected map.



    The route merely deviated slightly to the left in the second picture. However it is still flying over the North Pole, not the Atlantic. The deviation may be due to changes in winds aloft and/or traffic.






    share|improve this answer



















    • 14




      @Cloud That's a byproduct of the map projection used by FlightAware. The Earth isn't flat, so the shortest distance between two points won't show up as a straight line on that map (the actual shortest distance for flight planning purposes also takes winds into account). The ideal path isn't anything remotely close to a straight line.
      – Zach Lipton
      Aug 1 at 7:13






    • 4




      @Cloud It only looks like a big curve due to the limitations of drawing that type of projection. It isn't nearly as bad as it looks.
      – Mast
      Aug 1 at 8:30







    • 4




      @Cloud This great circle visualization of the ideal route might help you understand. Look at the 3D view to see how the route looks on a globe, then switch to the 2D view with the button in the top right and see how different it looks on a flat map.
      – kwc
      Aug 1 at 9:02






    • 1




      Some years ago, talking with a friend, I did a demonstration with a small ball and a tape measure. (He worked in a custom tailor shop in Bangkok.) The look on his face as he realized that the curved path really meant was PRICELESS.
      – John R. Strohm
      Aug 1 at 17:54






    • 3




      Wait, wait, wait! You mean the earth is ROUND?! So, why would NBA players mislead us?
      – TomMcW
      Aug 1 at 18:14












    up vote
    32
    down vote










    up vote
    32
    down vote









    The flight did not fly across the Atlantic. Rather, you're seeing the results of stereographic projection.



    More specifically, the Earth is round. Navigation needs to be thought of on the basis of a sphere. It is 3-dimensional, and if you have studied sphere geometry, you will know that it defies the rules of geometry we know in 2D - for example it is possible to construct a triangle with three 90-degree angles.



    The problem is that 3-dimensional objects cannot be displayed on a map, which is 2-dimensional. Therefore a mathematical formula is used to make a sphere look like a rectangle. The conversion is really skewed for regions near the poles. As a result, you cannot compare distances by measuring them on the projected map.



    The route merely deviated slightly to the left in the second picture. However it is still flying over the North Pole, not the Atlantic. The deviation may be due to changes in winds aloft and/or traffic.






    share|improve this answer















    The flight did not fly across the Atlantic. Rather, you're seeing the results of stereographic projection.



    More specifically, the Earth is round. Navigation needs to be thought of on the basis of a sphere. It is 3-dimensional, and if you have studied sphere geometry, you will know that it defies the rules of geometry we know in 2D - for example it is possible to construct a triangle with three 90-degree angles.



    The problem is that 3-dimensional objects cannot be displayed on a map, which is 2-dimensional. Therefore a mathematical formula is used to make a sphere look like a rectangle. The conversion is really skewed for regions near the poles. As a result, you cannot compare distances by measuring them on the projected map.



    The route merely deviated slightly to the left in the second picture. However it is still flying over the North Pole, not the Atlantic. The deviation may be due to changes in winds aloft and/or traffic.







    share|improve this answer















    share|improve this answer



    share|improve this answer








    edited Aug 1 at 8:37


























    answered Aug 1 at 4:31









    kevin

    25.9k789213




    25.9k789213







    • 14




      @Cloud That's a byproduct of the map projection used by FlightAware. The Earth isn't flat, so the shortest distance between two points won't show up as a straight line on that map (the actual shortest distance for flight planning purposes also takes winds into account). The ideal path isn't anything remotely close to a straight line.
      – Zach Lipton
      Aug 1 at 7:13






    • 4




      @Cloud It only looks like a big curve due to the limitations of drawing that type of projection. It isn't nearly as bad as it looks.
      – Mast
      Aug 1 at 8:30







    • 4




      @Cloud This great circle visualization of the ideal route might help you understand. Look at the 3D view to see how the route looks on a globe, then switch to the 2D view with the button in the top right and see how different it looks on a flat map.
      – kwc
      Aug 1 at 9:02






    • 1




      Some years ago, talking with a friend, I did a demonstration with a small ball and a tape measure. (He worked in a custom tailor shop in Bangkok.) The look on his face as he realized that the curved path really meant was PRICELESS.
      – John R. Strohm
      Aug 1 at 17:54






    • 3




      Wait, wait, wait! You mean the earth is ROUND?! So, why would NBA players mislead us?
      – TomMcW
      Aug 1 at 18:14












    • 14




      @Cloud That's a byproduct of the map projection used by FlightAware. The Earth isn't flat, so the shortest distance between two points won't show up as a straight line on that map (the actual shortest distance for flight planning purposes also takes winds into account). The ideal path isn't anything remotely close to a straight line.
      – Zach Lipton
      Aug 1 at 7:13






    • 4




      @Cloud It only looks like a big curve due to the limitations of drawing that type of projection. It isn't nearly as bad as it looks.
      – Mast
      Aug 1 at 8:30







    • 4




      @Cloud This great circle visualization of the ideal route might help you understand. Look at the 3D view to see how the route looks on a globe, then switch to the 2D view with the button in the top right and see how different it looks on a flat map.
      – kwc
      Aug 1 at 9:02






    • 1




      Some years ago, talking with a friend, I did a demonstration with a small ball and a tape measure. (He worked in a custom tailor shop in Bangkok.) The look on his face as he realized that the curved path really meant was PRICELESS.
      – John R. Strohm
      Aug 1 at 17:54






    • 3




      Wait, wait, wait! You mean the earth is ROUND?! So, why would NBA players mislead us?
      – TomMcW
      Aug 1 at 18:14







    14




    14




    @Cloud That's a byproduct of the map projection used by FlightAware. The Earth isn't flat, so the shortest distance between two points won't show up as a straight line on that map (the actual shortest distance for flight planning purposes also takes winds into account). The ideal path isn't anything remotely close to a straight line.
    – Zach Lipton
    Aug 1 at 7:13




    @Cloud That's a byproduct of the map projection used by FlightAware. The Earth isn't flat, so the shortest distance between two points won't show up as a straight line on that map (the actual shortest distance for flight planning purposes also takes winds into account). The ideal path isn't anything remotely close to a straight line.
    – Zach Lipton
    Aug 1 at 7:13




    4




    4




    @Cloud It only looks like a big curve due to the limitations of drawing that type of projection. It isn't nearly as bad as it looks.
    – Mast
    Aug 1 at 8:30





    @Cloud It only looks like a big curve due to the limitations of drawing that type of projection. It isn't nearly as bad as it looks.
    – Mast
    Aug 1 at 8:30





    4




    4




    @Cloud This great circle visualization of the ideal route might help you understand. Look at the 3D view to see how the route looks on a globe, then switch to the 2D view with the button in the top right and see how different it looks on a flat map.
    – kwc
    Aug 1 at 9:02




    @Cloud This great circle visualization of the ideal route might help you understand. Look at the 3D view to see how the route looks on a globe, then switch to the 2D view with the button in the top right and see how different it looks on a flat map.
    – kwc
    Aug 1 at 9:02




    1




    1




    Some years ago, talking with a friend, I did a demonstration with a small ball and a tape measure. (He worked in a custom tailor shop in Bangkok.) The look on his face as he realized that the curved path really meant was PRICELESS.
    – John R. Strohm
    Aug 1 at 17:54




    Some years ago, talking with a friend, I did a demonstration with a small ball and a tape measure. (He worked in a custom tailor shop in Bangkok.) The look on his face as he realized that the curved path really meant was PRICELESS.
    – John R. Strohm
    Aug 1 at 17:54




    3




    3




    Wait, wait, wait! You mean the earth is ROUND?! So, why would NBA players mislead us?
    – TomMcW
    Aug 1 at 18:14




    Wait, wait, wait! You mean the earth is ROUND?! So, why would NBA players mislead us?
    – TomMcW
    Aug 1 at 18:14










    up vote
    6
    down vote













    To complement the posted correct answers, consider this page: https://en.wikipedia.org/wiki/Antipodes#Cities



    It contains a list of cities that are exactly (or almost exactly) opposite one another on the spherical earth (antipodal); for example, Xi'an, China and Santiago, Chile.



    You could leave Santiago, and fly in a straight line (great circle, not a rhumb line) in literally any starting direction and still wind up close to Xi'an.



    Of course, range and availability of alternate landing fields along the way would limit your choices...






    share|improve this answer

























      up vote
      6
      down vote













      To complement the posted correct answers, consider this page: https://en.wikipedia.org/wiki/Antipodes#Cities



      It contains a list of cities that are exactly (or almost exactly) opposite one another on the spherical earth (antipodal); for example, Xi'an, China and Santiago, Chile.



      You could leave Santiago, and fly in a straight line (great circle, not a rhumb line) in literally any starting direction and still wind up close to Xi'an.



      Of course, range and availability of alternate landing fields along the way would limit your choices...






      share|improve this answer























        up vote
        6
        down vote










        up vote
        6
        down vote









        To complement the posted correct answers, consider this page: https://en.wikipedia.org/wiki/Antipodes#Cities



        It contains a list of cities that are exactly (or almost exactly) opposite one another on the spherical earth (antipodal); for example, Xi'an, China and Santiago, Chile.



        You could leave Santiago, and fly in a straight line (great circle, not a rhumb line) in literally any starting direction and still wind up close to Xi'an.



        Of course, range and availability of alternate landing fields along the way would limit your choices...






        share|improve this answer













        To complement the posted correct answers, consider this page: https://en.wikipedia.org/wiki/Antipodes#Cities



        It contains a list of cities that are exactly (or almost exactly) opposite one another on the spherical earth (antipodal); for example, Xi'an, China and Santiago, Chile.



        You could leave Santiago, and fly in a straight line (great circle, not a rhumb line) in literally any starting direction and still wind up close to Xi'an.



        Of course, range and availability of alternate landing fields along the way would limit your choices...







        share|improve this answer













        share|improve this answer



        share|improve this answer











        answered Aug 2 at 22:47









        DJohnM

        42648




        42648















            protected by kevin 2 days ago



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