Route notes
Why this routing works
This itinerary runs as a clean four-flight loop: Houston to Barcelona, onward to Istanbul, then across to Tokyo, and back to Houston. With no surface sectors or open jaws, the routing keeps all major transitions on one continuous ticket structure.
Over three weeks, the stop order spreads the longest intercontinental flying across the trip rather than stacking it back to back at the start. Barcelona and Istanbul work as sequential intra-regional stops before the longer move into East Asia and the final transpacific return.
In business class, this kind of multi-stop build is geared toward reducing friction on the longest legs while preserving a straightforward city sequence. October timing also places the trip in a shoulder-to-peak late-year travel window, so locking the order early helps keep the routing coherent.