US Aviation Market Data Insights

Find answers to your questions about the US aviation market, with flight data insights and analysis powered by OAG's Schedules Analyser.

Here are some highlights from this month's US market data:

• Largest airline: American Airlines
• Busiest airport: Atlanta Hartsfield-Jackson
• Busiest US domestic flight route: New York JFK to Los Angeles
• State adding most airline capacity: Illinois

The data is updated monthly. Seats are calculated as departing seats (one-way).

• American Airlines remains the biggest carrier in the US in November 2025 with 21% of the market, 20.7m seats.
• Southwest Airlines and Delta Air Lines both represent 19% share of the market with 18.6m and 18.4m seats respectively.
• Spirit Airlines decreased capacity by a further 36% vs November 2024, 1.4m fewer seats as they continue to navigate a second Chapter 11 process.
• The Big 4 carriers continue to represent a 75% share of the market.
                                                    
• 
• 

• This month, American Airlines added 862,500 more seats compared to November 2024, leading all carriers in seat growth. United Airlines also expanded, increasing capacity by 797,200 seats over the same period.
• Percentage wise JSX increased capacity at the fastest rate of 62%, but remains a smaller carrier. Breeze Airways continued to increase capacity at the fast rate of 41% vs November 2024.
  

• The busiest airline route in the US this month is New York JFK to Los Angeles with 301,200 seats, an increase of 10% capacity vs November 2024.
• The New York LaGuardia to Chicago route made the largest percentage increase of 16% to 297,900 seats.
• Capacity decreased most on the Las Vegas to Los Angeles and Honolulu to Kahului routes, both declining by 14 % vs November 2024.
• Capacity on the Denver to Chicago route reduced by 21%, taking it out of the Top 10 to be the 38th busiest route.
  

• The state of Illinois saw the largest increase in seats again this month, with capacity increasing by 471,700 seats vs November 2024.
• Percentage-wise capacity in Tennessee increased the most again amongst the largest states, up by 11% this month.
• Capacity decreased the most in Nevada again this month, by 293,200 seats, followed by California with 162,400 fewer seats vs last year. Nevada is heavily reliant on leisure travel (e.g., Las Vegas area) and reductions in demand for leisure travel combined with staffing and operational challenges are causing carriers to reduce capacity.
  

To view US flight capacity statistics from 2019-2025, click the button below to download the data.

*As of July 2025, international capacity is reported on a two-way basis (previously one-way departing).