Originally Posted by
Beltway2A
As others have noted, fare rules most likely won't allow routing through Japan for those routes. For TPE in particular though, TPE-FRA is around 4 miles shorter than NRT-FRA. I don't disagree that JAL offers one of the best Y products out there, but you'd be adding an extra 1300 or so miles to your journey in the opposite direction to get it.
Looking at the route China Airlines has to take from TPE to FRA to avoid Chinese airspace, Narita is not going ro be much of a mile wise detour, though of course the stop does add time.
But considering that people regularly fly London to Cape Town via DXB, or London Tokyo via DXB, I doubt this level of detour is much of a show stopper for most people
