read the question more thoroughly please.
I'm not an idiot, and you don't have to know how to split atoms to figure out that you can start a new airline wherever you want.
Just curious how you can start or even have a base at the top 20 airports... which clearly seems to be the case at DFW.
Learn to write what you mean please and/or stop being a p*** when people answer your questions. I'm not a mind-reader.
You didn't ask about additional
bases or hubs or anything to indicate you meant a second
(or third, whatever) base, you said "base airport". Your first base IS
a "base airport", ya know.
Even your 2nd post doesn't indicate what you truly mean, I'll have to assume based off your smartass reply that you mean how do people open additional
bases at DFW when you cannot: Airlines can get additional bases there by opening a 2nd base at GSW or DAL prior to the opening of DFW. When DFW opens, those at GSW are forced to move and those at DAL are presented with an option to move.