A few months ago, Alaska Airlines revealed that London Heathrow would be one of its European destinations. In early December, it secured slots from partner and fellow oneworld member American Airlines. And now, its flights are confirmed and on sale. It comes as Alaska’s first Boeing 787-9 (N784HA) was spotted in an all-white livery ahead of repainting into the new controversial livery.

When Alaska touches down at Heathrow next May, it’ll become the UK airport’s latest long-haul operator. Others joined its portfolio in 2025, including Air Peace, IndiGo, and Riyadh Air. Unusually, the trio debuted at Heathrow on the same day.

Alaska From Seattle To Heathrow

Credit: GCMap

Alaska’s first flight will leave Seattle on May 21, starting in time for the peak summer. Running daily, it’ll deploy the 300-seat Boeing 787-9 on the route, which will cover 4,171 nautical miles (7,725 km) each way. It is bound to make my celebratory Weekly Routes article (see the most recent edition).

Many airlines apply for slots at slot-constrained airports. Depending on the times and quantities required, some or all of them may be approved, whether at the exact time requested or before or after what was hoped for. They may then accept or decline them. Many decline them.

Unsurprisingly for Heathrow, Alaska’s request for a daily service was turned down in full. As such, it sought an alternative means to access the airport: using its partner American’s slots. Leasing slots from an incumbent carrier is a common way of accessing Heathrow or growing presence there.

American Has Reduced Flights On 3 Routes To Heathrow

Credit: Shutterstock

According to the latest Cirium Diio data, American plans 21 daily departures from Heathrow next July. Its offering has fallen from 24 daily departures in the same peak summer month in 2025. It is down from 25 daily takeoffs in July 2024 and 26 in the same month in 2023.

Compared to July 2025, American plans fewer services from Dallas/Fort Worth (from five to four daily, driven by transatlantic JV partner British Airways returning to the Texas hub next May), Miami (twice-daily to daily), and New York JFK (four daily to three daily). American will no longer leave Heathrow for the Big Apple at 5:00 pm; Alaska will now use it for its departure back to Seattle.

Excluding the pandemic-driven 2020/2021, American’s JFK frequency reduction means it’ll have the fewest-ever Heathrow flights in the peak summer. Part of the reason is that BA has grown its Heathrow-JFK flights from eight daily to nine (a frequency last seen in 2016), influenced by the ending of its Gatwick-JFK route. When American and BA’s combined offering is considered, they’ll have the same number of departures year-over-year.

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Seattle-Heathrow Will Now Have 5 Daily Departures

Credit: Virgin Atlantic

In the 12 months to September 2025, booking data indicates that 274,000 round-trip local passengers flew between Seattle and Heathrow. It was a good-sized market. Due to having nonstop flights, BA, Virgin, and Delta transported the most people, while Icelandair was the top operator for indirect passengers.

BA, in particular, was heavily reliant on connecting traffic. More than one in two Seattle passengers transferred to another flight at Heathrow. Italy, India, the wider UK, Spain, and Germany were the top five country markets, and Seattle-Delhi was the top city pair. Alaska will, of course, carry passengers via its Seattle hub, although the 6:45 pm arrival is quite late.

Next summer, Heathrow-Seattle will have five daily departures again, which will be the joint-highest on record. It was last available in 2023, when American last served the market. BA will run twice daily (777-300ER/787-10), while Alaska will be daily (787-9), Delta will be daily (A330-900), and Virgin will be daily (787-9). Oneworld will overtake SkyTeam again.