Originally Posted by
wetrat0
To my knowledge, Southwest is the only US airline that currently sells direct itineraries where continuing passengers are permitted (sometimes, required) to stay on the plane during the stop.
Maybe a fluke example, but if you want to fly to/from China on AA, DL, or UA, there is an ICN stop and leaving the plane there is not even an option (for passengers). Still, aa.com displays DFW-ICN and ICN-PVG as separate segments (with the same flight number).