Originally Posted by
Hypeman123
Gotcha. Thanks for listing out the other routes as well!
It's worth noting that is specifically those routes, and not "any lie-flat equipped aircraft". Believe it's basically the same as DL with domestic D1 except UA did not adopt the 24-hour upgrade rule that DL did, and the front cabin on long-haul Hawaii flying is still branded "United First".
If you happen to find a lie-flat aircraft on e.g. SFO-ORD or SFO-IAD, you can still get a free upgrade there, although usually you'll be too far down the list.