As much as 99%: The 10 US-Europe routes with the highest load factors

According to the US Department of Transportation, ~77 million passengers flew between the US and Europe in the 12 months to November 2024. More than three in 10 of the country's international passengers flew to/from the continent.

Some 37 carriers operated 500+ routes and 340+ airport pairs. They filled an average of 83% of the seats for sale.

Seat load factors: a summary

An airline's seat load factor is the proportion of available capacity (whether seats or seat miles) filled by traffic (whether passengers or revenue passenger miles).

If too much capacity is available relative to demand, fares and yields will reduce, but loads should rise.

Conversely, if there is too little capacity for the demand at a particular price, fares and yields may increase, but loads may fall while leaving revenue on the table. These things will depend on other factors, including competition.

If capacity rises faster than traffic, loads will fall, meaning fewer passengers to generate the required revenue, and each passenger will cost more to carry, and vice versa.

A route with a very high load factor may look like it performs very well, but it is about how it was achieved.

It could simply be full of lower-yielding leisure and visiting friends and relatives traffic, the lowest segments for yields due to lower premium demand. It may not mean good performance unless costs are low enough for this.

They were as high as 99.1%

As summarized below, the analysis of 500+ routes for the 12 months to November 2024 shows the 10 routes with the highest load factors. Most are point-to-point, summer seasonal, and focused on leisure or visiting friends and relatives demand.

Three of them only had a weekly service, with the minimal capacity and nature of demand helping to fill the aircraft.

For year-round links, frequencies were typically reduced in the off-season (helping with fares, yields, and loads) and increased in the primary season (benefiting from peak demand and pricing).

The average load is based on each route's operating period in the 12 months examined. Figures would have varied within that period.

For example, the US DOT shows Delta's New York JFK-Prague service, which operated between May and October 2024, ranged from 87.9% to 98.0%. But did it do as well financially as these numbers suggest? That's an entirely different question.

Iberojet was number one

Iberojet is in first place with its sole US route: Madrid to Orlando. The Florida airport was the carrier's first US destination when flights launched in June.

With a time-limited service, it relied on Avoris and its Disney-specialized tour operators to drive sales and fill its high-capacity, 432-seat, all-economy A350-900s to a heady 99.1%.

It was the USA's top foreign airline with the fewest flights during its short seasonal operation.