US airlines take more discipline and less capacity into 4th July

IBA has found that US airlines are taking a more disciplined approach to capacity deployment during this year's July 4th travel period, with capacity slightly down despite continued strong holiday demand.

Data from the IBA’s Insight aviation intelligence platform shows total scheduled seats for 27th June to 4th July period have eased slightly compared with 2025, following two years of steady growth.

Domestic capacity continues to account for around 85% of all July 4th airline seats in the US, with the balance between domestic and international operations remaining broadly stable. While overall capacity remains above 2023 levels, the slight year-on-year decline suggests airlines are becoming increasingly selective in how they deploy seats during one of the busiest travel periods of the year.

Domestic scheduled seats are down 2.0% year-on-year, while international seats have fallen 2.1%. International available seat kilometers (ASKs), however, are almost unchanged, declining by just 0.3%, indicating airlines are maintaining longer-haul flying while trimming frequencies elsewhere in their networks.

The trend is particularly visible among low-cost carriers. Domestic LCC seat capacity is down 9.1% year-on-year, while full-service carriers have increased capacity by 2.0%, reflecting continued changes in the competitive landscape following the exit of Spirit Airlines earlier this year.

The changes (by seats) to the US’ five largest city pairs shows how uneven the reshaping of capacity has been. New York - Chicago is up 5.7%, but New York - Los Angeles is down 7.1%, New York - Atlanta is down 12.4%, New York - Orlando is down 11.3%, and New York - Miami is down 5.8%.

Spirit’s exit has clearly disrupted the competitive map, but airlines may not yet have had enough time to fully rework peak summer schedules. Instead, capacity appears to be being removed, reallocated or backfilled selectively rather than replaced one-for-one. Frontier is one of the stand-out growers, up 18.2%, while among the big three, United is up 3.3%, American is up 2.5%, and Delta is broadly flat.

Dan Taylor, Head of Consulting at IBA, said: "July 4th capacity tells a punchy story of fewer low-cost carrier seats, more full-service carrier capacity, and a market being managed for margin rather than volume.”

“With the adjustment to Spirit’s exit still taking shape, growth is becoming more cautious, capacity more deliberate, and the focus appears to be shifting from adding seats to improving yield.”