Spirit’s Shutdown Could Reshape Airport Growth Assumptions

As the aviation industry debates which carriers will absorb Spirit Airlines’ routes following the carrier’s shutdown, another question is beginning to emerge for airport operators: what if much of that capacity never comes back?

According to Jeffrey Sigmon, manager, U.S. Travel & Transportation at Arthur D. Little, airports should prepare for a recovery that is uneven, slower than many expect and potentially permanent in some smaller markets. While major trunk routes are likely to regain service through existing carriers, many secondary airports and leisure-focused markets could see long-term structural losses.

“We foresee 60 to 70 percent capacity replacement within 24 months, but it will be uneven,” Sigmon said. “The structural loss is concentrated in 30 Spirit-monopoly markets that represent about 6 percent of Spirit’s seats, and that capacity will be much slower to return or vanish entirely.”

The implications extend well beyond airline competition. For airports, the loss of Spirit’s ultra-low-cost carrier (ULCC) model could affect everything from concession revenue and passenger facility charge collections to terminal utilization assumptions and long-term capital planning strategies.

Capacity Recovery Won’t Be Even

Sigmon said much of Spirit’s network already overlapped with major carriers prior to the shutdown. Roughly 93 percent of Spirit’s 2025 seats operated in markets where the Big 3, Southwest or JetBlue already had a presence, making frequency replacement on major routes more likely.

However, replacing all of Spirit’s lost seats will be difficult in the near term.

“Several constraints shape the near-term outlook,” Sigmon said, citing fuel costs, weak airline financial performance, pilot and crew availability and limited aircraft supply.

Summer schedules were finalized months before the shutdown, meaning significant replacement capacity may not materialize until late 2026 or into 2027. While Frontier represents the most natural replacement carrier in many markets, Sigmon noted the airline lacks the immediate fleet scale necessary to absorb Spirit’s entire network while maintaining its own growth plans.

At the same time, major network carriers are unlikely to broadly replace Spirit’s footprint.

“The Big 3, together with Southwest, account for roughly 80 percent of domestic capacity and operate predominantly hub-and-spoke or focus-city networks,” Sigmon said. “Southwest is expected to selectively cherry-pick the most attractive opportunities, focusing on high-demand, high-margin routes rather than broad-based replacement of capacity.”

That selective replacement strategy could leave some airports exposed.

Revenue Pressure Could Arrive Quickly

For airport finance teams, the first impacts may emerge in non-aeronautical revenue streams.

“Concessions and parking take the first hit because they are immediate, variable and tied directly to enplaned passengers,” Sigmon said.

Spirit carried roughly 82,000 daily passengers systemwide at the end of 2025, according to Sigmon, feeding parking facilities, food and beverage operations and retail activity in real time. Landing fee adjustments typically lag by 30 to 90 days as airports recalibrate rates and airline payments.

Passenger facility charge revenue may create an even larger long-term concern.

“The least visible but most painful hit is PFC revenue, which is a direct function of enplaned passengers and flows straight to debt service,” Sigmon said.

Arthur D. Little recommends airports immediately rebuild traffic forecasts from the ground up rather than applying temporary adjustments.

Sigmon said airports with strong legacy or Frontier presence should assume roughly 50 to 60 percent passenger recapture in year one and 70 to 80 percent in year two, while airports heavily dependent on Spirit could experience materially slower recovery.

At the same time, airports may see changes in passenger mix that partially offset losses.

“While overall volumes may decline, this mix shift can partially offset the impact, as spend per enplanement typically increases by 10 to 20 percent,” Sigmon said, referring to higher-spending legacy airline passengers replacing some ULCC traffic.

Smaller Airports Face the Greatest Risk

Not all airports will experience the shutdown equally.

According to Sigmon, airports where Spirit represented more than 10 percent of total seat share and had limited overlap with legacy carriers or Frontier face the greatest risk of long-term service loss.

He identified Latrobe, Atlantic City, Fort Lauderdale, Myrtle Beach, St. Thomas, Detroit and Orlando among the airports with elevated exposure. While larger leisure hubs like Orlando and Fort Lauderdale are expected to recover, smaller airports could struggle to replace lost connectivity.

“Atlantic City and Latrobe face an existential question,” Sigmon said.

The situation could also force changes to long-standing air service development strategies.

“The post-2010 ASD playbook leaned heavily on ULCC incentive packages because Spirit, Frontier, Allegiant and Avelo were the only carriers willing to start service in thin markets,” Sigmon said.

With fewer ULCC operators remaining, smaller airports may need to shift away from incentive-heavy approaches and instead demonstrate stronger underlying demand fundamentals.

Rethinking Terminal Planning

The shutdown may also challenge airport infrastructure assumptions developed during the rapid expansion of ULCC service over the last decade.

“The reality is that any capacity assumption built around ULCC growth needs to be revisited for 2026,” Sigmon said.

He pointed to Fort Lauderdale as an example, where Spirit operated approximately 79 daily departures and 15,700 daily seats by the end of 2025. Even with partial replacement service, airports could still experience lower frequencies and reduced gate utilization.

Dedicated ULCC concourses and terminals may become especially vulnerable.

“Several projects, particularly across Florida and Northeast secondary airports, were partially underwritten on ULCC growth assumptions that may now be at risk,” Sigmon said.

In the near term, Sigmon said airports should focus on reducing operational costs rather than maintaining full-scale operations in anticipation of a rapid recovery.

“Mothball selectively rather than uniformly,” he said. “Consolidate operations into fewer concourses during off-peak hours, reduce HVAC and lighting loads in low-traffic concourses and terminals.”

A Different Competitive Environment

Passengers are also likely to feel the impact.

Sigmon expects average fares in former Spirit overlap markets to rise approximately 8 to 15 percent during the first year following the shutdown, particularly where Spirit was previously the only ULCC option.

That could alter traveler behavior, especially in shorter-haul leisure markets.

“Price-sensitive leisure travelers will substitute to driving on routes under 500 miles,” Sigmon said. “Some demand will be lost entirely.”

For airport executives, the message is clear: prepare for a fundamentally different airline landscape rather than a quick return to pre-shutdown conditions.

“Political pressure to ‘replace Spirit passengers’ will be significant,” Sigmon said. “But the reality is that Spirit is unlikely to return and any replacement capacity will look vastly different.”