The latest data from leading aviation analytics provider, OAG, shows a diverse performance across the global aviation industry in September 2025. While some airlines and regions are experiencing robust growth, others are seeing a contraction in capacity and frequency compared to the previous year.
Airlines Add Frequency, with United and Delta Leading the Way
United Airlines continues to lead the way in adding extra flight frequencies among the top 20 airlines, with 6,900 more flights compared to September 2024. This significant increase is a key factor in United’s capacity strategy. Close behind is Delta Air Lines, which has added 5,500 more frequencies.
In a notable shift from earlier this year, Indian low-cost carrier IndiGo has reduced its flying by 0.5% compared to last year, a departure from the strong growth it demonstrated in the first half of 2025.
Fastest Growth and Largest Reductions
Turkish Airlines stands out as the airline with the fastest growth rate this month, increasing its capacity by an impressive 7.9%. Conversely, Azul Airlines of Brazil is experiencing the largest reduction, with a decrease of 9.2%.
Regional and Domestic Market Performance
The world’s largest domestic markets are showing a mixed performance. Indonesia has seen the most significant fall, with capacity down by 12.2% this month. Japan, India, and the USA also saw their domestic capacity contract.
In contrast, the domestic market in Turkiye is experiencing strong growth, up by 16.2% and adding 740,000 more seats compared to September 2024. Other markets with significant growth include Canada and Australia, both up 7%, and Brazil, up 5%.
Global Capacity and Regional Growth Trends
OAG forecasts this month’s total capacity to be 515.1 million seats, a 2.4% increase year-on-year. This is lower than the peak month of July, which recorded 559 million seats.
Among IATA regions, Central Asia continues to show the strongest year-on-year growth, up by 12.1%. All four African regions are also growing, with Southern Africa leading the continent with a 10.3% increase.
However, three regions are seeing a decline in capacity compared to September 2024: North America is down 0.4%, Upper South America is down 2.7%, and the Caribbean is experiencing the most significant decline at 3.4%.
