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Flying east is faster so I expect that if the destination are on opposite points or closer, that the flights between them always be to the east.

For example Los Angeles to Delhi. I see the fly is over the north pole.

Wouldn't it be faster to always go east?

http://www.gcmap.com/mapui?P=lax-del&DU=mi

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  • $\begingroup$ You mean east as opposed to north? $\endgroup$ – gerrit Apr 27 '18 at 13:46
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    $\begingroup$ I assume you're referring to trade winds/prevailing westerlies as mentioned in aviation.stackexchange.com/questions/2549/… $\endgroup$ – Barry Carter Apr 27 '18 at 19:11
  • $\begingroup$ I meant as opposed to east to west and west to east. Unless they all do that through north pole, in that case the question can be opposed to north pole flights. $\endgroup$ – Ronen Festinger Apr 29 '18 at 7:52
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FlightAware suggests there are no non-stop flights from LA to Delhi.

Was certainly going to point out that we're pretty limited on ultra long-haul flights still, and it'd take a very special flight setup to make your scenario. You'd need both:

  • Two locations about 180° longitude apart so that the distance going east vs. the distance going west is insignificant for both legs enough so the jet stream gains flying east pay off.
  • Two places at just the right latitudes. They need to be at latitudes far enough south (in the NH) that it's not much shorter to just fly the great circle through the North Pole [or near if not 180° apart].
    Here is a graph showing the ratio of the distances of the path crossing the Pole vs the distance of the constant-latitude path, for places 180° longitude apart [derivation in comments]... which shows it's 50% longer to fly around the 60° latitude circle than to fly over the Pole).
    However, the further equatorward (south in the NH) you go, the less benefit you'd get from the jet stream as upper wind speeds are typically much slower further south, and you'd spend less of your flight time in the jet stream. (Here's a current jet stream map).

Keep in mind that the jet stream is only going to add 100-200 mph in general. So that's only like 1/3 of the cruising speed of a large jet. Of course the benefits will show up in both in fuel usage (and the additional weight benefits of carrying less fuel) and in travel time (people like quicker flights, and you can run more flights in a year and/or pay crew less). So despite being a longer distance, if it cut enough time/energy it might just be worth it.

And, well go figure, it turns out you weren't far off at all! Because there actually is a direct flight from San Francisco to Delhi. And it looks like they do exactly as you suggested!

enter image description here enter image description here
(Click images for larger versions)

These are Air India flights 173 and 174. The official flight does make a jaunt from Delhi to Bengaluru and back once it completes the SFO-DEL leg. But you could indeed go around the world from Delhi to San Francisco to Delhi without any other stops... in looks like around 36 hours.

Pretty cool!

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    $\begingroup$ (To compare polar distance to equal-latitude distance, the Great Circle distance is (2πR*(2*(90-φ))/360), times 2 to include the return trip. The equal-latitude distance is 2πR*cos(φ), as it's the circle circumference at that latitude... R stands for the radius of the Earth [which will cancel] and φ stands for the latitude.) $\endgroup$ – JeopardyTempest Apr 28 '18 at 7:36
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    $\begingroup$ And certainly no idea how much the flight may vary over paths, as following the jet stream should prove quite an economic benefit for them. Interesting how different the two segments are in latitude (though that sort of matches the current jet stream pattern?) An intriguing subject to look into, definitely! $\endgroup$ – JeopardyTempest Apr 28 '18 at 9:40

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