Rocky Mountain Ultra Low: Can Frontier Airlines replicate the great success of other ultra-LCCs?

If Southwest is the godfather of low-cost aviation, then Spirit Airlines is its present manifestation, a symbol of what has come to be known as the ultra-low-cost carrier. Put another way, Spirit is low-cost aviation’s new frontier, one so profitable that another U.S. airline is now unsurprisingly trying to cross that frontier as well. That airline, appropriately enough: Frontier.