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.

• Which are the top airlines in the USA?
• What's the country's busiest airport?
• Which US domestic flight route is busiest?
• Is there more domestic or international capacity in the US aviation market?
• And more.

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

• American Airlines remains the biggest carrier in the US this month with 21% of the market, 21.4m seats.
• Southwest and Delta Air Lines remain a close second and third largest, with 19% share each.
• The Chapter 11 filing from Spirit Airlines is reflected in a further capacity decrease this month of 17% vs April 2024, a reduction of 720,200 seats, as they reorganise their network.
• In contrast Allegiant Air increased capacity most percentage wise within the Top 10, by 18%.
  
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• United Airlines added over 961,000 seats vs April 2024, whilst American Airlines added 755,700 seats and Delta Air Lines added 724,400 seats.
• Breeze Airways increased capacity by 48%, 201,400 seats.
• Mexican carriers, Vivaaerobus and Volaris, increased capacity by 45% and 28% respectively.
• Spirit Airlines and South West Airlines reduced capacity most by 720,200 and 281,300 seats respectively.
  

• The busiest route remains Denver - Phoenix with 288,400 seats, constant vs last year.
• Capacity grew fastest on the New York JFK - Los Angeles route, increasing by 14% vs April 2024 and making it the second busiest domestic route.
• Capacity reduced again this month on the Atlanta - Fort Lauderdale route, with 34,300 fewer seats - a reduction of 14%. It also reduced by 7% on the Atlanta - Orlando route.
• Capacity on the Denver - Las Vegas route also continued to reduce this month, by 12% vs April 2024. Capacity also reduced by 11% on the Honolulu - Kahului route this month.

• Overall capacity in April 2025 increased by 3% vs last year, an additional 2.5m seats.
• The state of California added the most seats again this month, increasing capacity by 410,500 seats vs April 24.
• Percentage wise capacity increased most in the District of Columbia increasing by 11%, followed by Pennsylvania, Massachusetts and Tennessee all increasing by 8%.