Originally Posted by Brickfire

Not incorrect.

But at some scale, it make sense to avoid paying for X thousand hotel nights/year. And to have reserve coverage for all those AM departures. IDK what scale that is - I suspect for narrowbodies it's north of a dozen airplanes staying overnight. Which would mean something like a 5:30 and a 7:30 to every hub. Not many candidates ... the list of large airports/cities that are not already UA bases is Dallas, Philly, Atlanta, Phoenix, Boston, Detroit, Seattle, Minneapolis. Cities that aren't somebodies hub are the St. Louis, Nashville, New Orleans, Portland range. I agree none of those places make sense if you can grow your current bases. Question is how much growth can current bases support and how much it costs to open an outstation.