Interesting one, I would have never suspected that and as the crow flies, it would be. But I wonder currently with the Russia issue if that's really the case, would the 'avoiding Russian airspace' LHR-HND route be further? It's only about 1200 miles shorter on Great Circle Mapper, so the detour may make it longer in both time and miles actually flown. I know I did PVG-LHR and back last month and even with PVG being a bit further south, it was a VERY long flight, much much more then I was used to on East Asia to Europe.