the shorter great circle route is the US one
Here I am thinking that any distance between two points on a sphere can only be connected by one greatcircle...
I'm assuming we're talking two contending optimum tracks here.
Anyway, galleypower, let's assume GIG (say, 2249S14023E) and NRT (say, 3546N4315W), then that greatcircle runs due north, almost smack over the pole and then south to NRT, say, 167 degrees, some 10.000 NM or some 22 hours+ at LRC, zero wind.
Free tracking, single fuel stop: Greenland is nicely positioned on-track, with Iceland a little offset to the right.
Multi-stop (and airways) requirement: Azores (or even Africa), then as wind/temperature/greatcircle optimum as possible over the western hemisphere.
Fact remains that Earth is not a sphere, so a northern route is less distance, add to that predominantly western winds.
When looking at those upper wind charts (fading practice, I know), aside from jets have a lookout for big weather systems (storms, hurricanes) as they will greatly affect your optimum route, resulting in unexpected better routeings and groundspeeds.
But you knew all that already, right?
Cheers, Max
