For the second time in less than a year, Spirit Airlines has filed for bankruptcy protection, raising fresh concerns about the stability of the ultra-low-cost carrier model in the United States. The news comes as the airline struggles with mounting debt, rising fuel costs, and Pratt & Whitney engine reliability issues that have left passengers frustrated with repeated cancellations and delays.

Repercussions

If Spirit were to cease operations, the disruption would be both immediate and widespread. The airline currently operates more than 600 daily flights across the U.S., Latin America, and the Caribbean. On peak days, that translates to well over 100,000 available seats, many of which are relied on by budget-conscious travelers. Losing this capacity would strand tens of thousands of passengers and cause ripple effects across airports where Spirit has built a strong presence.

Take Fort Lauderdale-Hollywood International Airport (FLL) as an example, where Spirit accounts for nearly 30 percent of all traffic. The carrier also holds double-digit market shares in Orlando (MCO), Las Vegas (LAS), and Detroit (DTW). With a fleet of roughly 200 Airbus A320-family aircraft serving more than 80 destinations, a collapse would leave the entire leisure-heavy routes underserved, particularly to Florida, the Caribbean, and Mexico.

United is Taking Advantage

Recognizing the opportunity, United Airlines quickly announced expanded winter schedules and additional routes that overlap with Spirit’s network. By adding frequencies on high-demand leisure routes and deploying larger aircraft, United is positioning itself to absorb some of the stranded demand. Just as importantly, United can leverage valuable airport slots at its main hubs like Chicago O’Hare (ORD) and Newark Liberty (EWR) to tighten its hold if Spirit retreats.

Analysts estimate that United and other legacy carriers could absorb 40% to 50% of Spirit’s capacity within months. However, passengers would almost certainly face higher fares.

According to U.S. Department of Transportation data, the average domestic airfare in the country was around $400 in 2025. Spirit’s average base fare, by contrast, hovered closer to $100 before add-ons. That pricing power kept downward pressure on fares across the industry. In fact, airlines like Spirit forced the majors to introduce “basic economy” tickets in the mid-2010s, an option designed to compete with ultra-low-cost carriers without undercutting their more profitable fare classes.

Data courtesy of U.S. Dept of Transportation

Lack of Competition

This is why competition matters. It not only keeps fares lower but also pushes carriers to innovate and improve. If Spirit disappears, travelers could see fewer rock-bottom fares and less incentive for legacy carriers to maintain competitive pricing.

For now, Spirit’s future hangs in the balance. While the airline works to restructure, larger players like United are already moving quickly to fill the void, setting the stage for a reshaped U.S. air travel landscape.