29% More Flights: Inside United Airlines' Growing European Network At Chicago O'Hare

For many years now, Chicago O’Hare International Airport (ORD) in the US federal state of Illinois has been one of United Airlines’ most important hubs for both domestic and international flying. The city is also home to the US ‘big three’ legacy carrier and Star Alliance founding member’s corporate HQ.

The extent of United’s presence in Chicago is underlined by the fact that, this December, it is operating 29% more flights on its various long-haul routes to and from Europe than was the case this time last year. In this article, we will dive deeper into the data to examine United’s strong European growth.

Crunching The Numbers

According to present scheduling data made available by Cirium, an aviation analytics company, United Airlines is set to operate a grand total of 721 flights on routes between Chicago and Europe this month, offering 166,283 seats in the process. Compared to December 2024’s figures of 559 flights and 136,648 seats, these represent respective increases of 29% and 21.7%. Available seat miles (ASMs) are also up by a factor of 20.8%.

As far as aircraft utilization is concerned, the Boeing 767-300ER is United’s top jet for Chicago’s European routes, accounting for 370 of the 721 flights. Compared to last December, this represents an increase of 54.8%. Meanwhile, the 787-10 accounts for 256 flights (up 1.2%), with the 787-8 rostered to operate 95 (up 41.8%). Omar Idris, United’s Vice President of Chicago O’Hare, commented earlier this year, in May 2025, that:

“This is a historic time for our hometown hub. We’re not only offering our customers the largest network from Chicago, but also new industry-leading amenities both at the airport and in the air.”

Two Routes Are Being Served This December That Didn’t See Flights Last Time

A key factor in United Airlines’ European growth at Chicago O’Hare International Airport has been its extension of two previously seasonal summer routes into the winter. One of these serves Barcelona, which, in 2024, only had flights between May and October. This time around, however, they have run from April to December, albeit with quite a limited schedule this month, with just one outbound and two inbound flights this time.

A destination whose extension has resulted in a significantly greater capacity uplift in December, however, is Dublin Airport (DUB) in the Republic of Ireland. Served between May and October last year, United took the decision to enhance its coverage to year-round in 2025, with flights running from March to December. According to the Irish Times, the carrier has also increased capacity by deploying larger Boeing 787-8 Dreamliner aircraft.

This month will see United serve Dublin more or less daily from Chicago, with a grand total of 30 flights scheduled in each direction on this popular route across the North Atlantic Ocean. The only exception is December 24, which will have no outbound flight, and December 25, with no inbound service. Flying west, UA980 leaves ORD at 6:35 pm and lands at 8:10 am the next day, while UA981 leaves DUB at 10:40 am and lands at 1:30 pm.

Other Increases

As it happens, the route to Dublin actually represented United’s second-biggest European increase from Chicago this December, with 30 more flights in each direction compared to this time last year. The only corridor with more services added was to London Heathrow Airport (LHR), with 31 extra round trips. The addition of these flights has taken United’s coverage on the route this December from two return flights a day to three.

Elsewhere, Rome (FCO) has seen the third-largest increase in terms of raw flight numbers, with 15 services added in each direction. However, as this route only had two outbound and three inbound flights last December, this represents a huge proportional increase of 750% flying west and 500% flying east. Meanwhile, Zurich (ZRH) has been upgraded to a daily frequency, compared to 26 outbound and 27 inbound flights last December.