Shake-up at world’s busiest airport underscores broader trends

Frontier knocks out Southwest as Atlanta’s No. 2 carrier

Move over, Denver, make way for Atlanta.

That’s the story at Frontier Airlines, where Atlanta is poised to displace Denver as the budget carrier’s busiest airport. It’s a big shift for Denver-based Frontier, whose hub at Denver has long been its busiest airport.

It also comes amid a broader shakeup at Frontier under new CEO James Dempsey, who assumed the role less than three months ago after the abrupt resignation of previous chief executive Barry Biffle.

High on Dempsey’s list: Fixing Frontier’s notoriously unreliable operation. “The status quo is not acceptable,” he said last week during Frontier’s quarterly earnings call.

TPG’s Sean Cudahy notes that it’s “been a lingering frustration for passengers — especially those who get stranded on routes the airline only flies two or three times per week.”

But for those of us who like to track airline route changes — count me among those — the emergence of Atlanta as Frontier’s top airport is a big deal in its own right, and one that hints at other changes afoot among U.S. carriers.

Among those is Southwest Airlines’ slow, ongoing retreat from Atlanta, where it immediately became the No. 2 carrier at the airport following its merger with Atlanta-based AirTran Airways that closed in 2011. But the second-place spot changed hands in 2025, when Frontier moved past Southwest — trailing only Atlanta-based Delta Air Lines, which dominates traffic at the world’s busiest airport.

For Southwest (which is undergoing seismic changes of its own), the drop to No. 3 in Atlanta comes as it has focused on Nashville — where it is the top carrier — as its primary base in the region.

That’s where Frontier’s opportunity comes in, as it looks to reverse its financial fortunes after losing $137 million in 2025.

Aside from a renewed focus on reliability, Frontier is tweaking its schedules and routes to focus on what it believes are its most profitable opportunities.

That includes Atlanta, where the slow pullback by Southwest — coupled with big schedule cuts by bankrupt rival Spirit Airlines — has opened the door for Frontier to grow.

The shift in Atlanta caught the attention of The Cranky Flier aviation blog, which did a deep dive on Frontier’s latest route map changes.

“There is one thing that stands out above all. Atlanta,” writes The Cranky Flier in a data-heavy post. “And Frontier continues to really, really like what it sees. It is by far the airline’s largest station this summer. This is a massive growth engine for Frontier, and it desperately needed to find one. The question is ... is it doing well for Frontier or is it just better than the other places where it could put its airplanes?”

Stay tuned …

---