Originally Posted by
Sopwith
My understanding is that in airline lexicon "direct" means you get to your destination without changing flight number, but there may be stop(s), or rarely, a change in aircraft. "Non-stop" means there are no scheduled stops to your destination. Most of the time there won't be an unscheduled stop either.
"non-stop" is sufficient,
"direct, non-stop" combined is redundant,
"direct" on its own can be misleading and generally serves no purpose as it does not mean what many non-aviation people think it does (i.e. non-stop). I've been on direct flights with stops that include:
- continuing passengers stay on the plane at the intermediate stop,
- continuing passengers deboard/board the same plane at the intermediate stop,
- continuing passengers change planes at the intermediate stop.