Europe-US flights see seasonal shifts as some airlines report low seat occupancy

Finnair ranked sixth among carriers with lower load factors but has seen growth in its US services due to limited access to Asian destinations following Russian airspace restrictions. Its passenger traffic increased by around ten percent due to higher frequencies rather than new routes. Finnair’s load factor rose by over four percentage points to reach 78.1%, compared to the previous year.

According to DOT data for May 2024 through April 2025, Singapore Airlines had the lowest seat load factor at 69%. The airline ended its Singapore-Manchester-Houston route in March 2025; its remaining service is Singapore-Frankfurt-New York JFK—the longest one-stop passenger flight into the US.

Neos followed with a load factor of 75.8%, influenced by Palermo-New York JFK flights started last June and not including newer Bari flights that began after the reporting period.

Azores Airlines had several poorly performing routes and has since reduced its US network from nine routes down to four. Five links have been cut: Funchal-Boston, Funchal-New York JFK, Porto-Boston, Porto-JFK, and Terceira-Oakland. Porto-Boston had an especially low load at just over sixty-two percent; TAP Air Portugal has since replaced it with more frequent overnight service using A321LR aircraft.

Other airlines listed included Edelweiss (77.3%), Aer Lingus (78.1%), Virgin Atlantic (78.7%), Austrian (79.1%), Norse Atlantic UK (80.3%), and La Compagnie (80.4%). Individual underperforming routes contributed to these averages—for example, Zurich-Denver for Edelweiss operated only seasonally until September 2024.

Aer Lingus saw nearly three million round-trip passengers between Ireland and the US in this period—a four percent increase year-over-year—driven by launching or relaunching several routes including Dublin-Denver, Las Vegas, Minneapolis, and Nashville.

Three out of four Aer Lingus’ worst-performing transatlantic routes were new additions falling below seventy percent seat occupancy; Denver-Miami also posted a sub-seventy-percent winter average.

The findings highlight how both established carriers and newcomers can face challenges achieving high seat occupancy on transatlantic flights depending on route maturity and market dynamics.