Delta’s Optimistic Seattle To London Heathrow Expansion

Delta Air Lines plans to massively expand its presence between Seattle and London this coming winter, as flagged by @IshrionA. I suspect this is intended as a preemptive move given Alaska Airlines’ long haul expansion, but I can’t help but think the airline is being a bit too aggressive…

Delta goes double daily between Seattle and London

For the upcoming 2025-2026 IATA winter season, Delta plans to operate 2x daily flights between Seattle (SEA) and London (LHR). The flights will operate with the following schedules:

DL292 Seattle to London departing 6:15PM arriving 11:00AM (+1 day)
DL20 Seattle to London departing 7:55PM arriving 12:40PM (+1 day)

DL293 London to Seattle departing 12:20PM arriving 4:00PM
DL21 London to Seattle departing 3:50PM arriving 7:30PM

The 4,801-mile route will be operated by a combination of Airbus A330-200s and A330-900neos. The flights are blocked at just under 10 hours eastbound, and just over 10 hours westbound.

For context, this past winter, Delta operated in the market 3x weekly. So to go from 3x weekly flights to 14x weekly flights is a unusual level of growth. What’s going on here?

• This past winter, Delta launched a seasonal 4x weekly London to Orlando flight, and those Heathrow slots came from the Seattle service, which was reduced from 7x weekly to 3x weekly at the time; so Delta is essentially moving those 4x weekly slots back to Seattle, so that it can resume daily flights
• Regarding Delta’s second daily flight to Seattle, I have to imagine that this is a swap for Virgin Atlantic’s once daily flight in the market, given that the two airlines have a joint venture, and coordinate schedules

So at a minimum, the Delta and Virgin Atlantic joint venture is going from 10x weekly flights to 14x weekly flights in the market.

I don’t see this level of winter capacity lasting

We’ll see how this plays out, but I’m just going to go ahead and put in my guess that the 14x weekly Delta flights between Seattle and London won’t last for the winter season, and that there will be cuts.

It’s one thing if Delta were simply taking over Virgin Atlantic’s frequencies, and going from 3x weekly flights to 10x weekly flights. But then adding another 4x weekly flights as well? Delta really expects this upcoming winter season to have more demand between Seattle and London than last season’s service? I just don’t see it.

For what it’s worth, British Airways operates 10x weekly flights in the market, and has a massive competitive advantage over Delta:

• It partners with Alaska, which has more connectivity in Seattle than Delta does
• It has a massive regional and global connecting network in London, much bigger than with Virgin Atlantic; that’s especially important in winter, where transatlantic demand just isn’t as high

We know that Alaska is launching long haul flights out of Seattle. The airline will first fly to Tokyo Narita and Seoul Incheon, but plans to expand to Europe in 2026. I can’t help but think that Delta beefing up in the Seattle to London market is partly a competitive response to that, though I’m not sure what exactly it’s going to accomplish. It’s going to be interesting to see how the “battle in Seattle” evolves.

Figuring out where to fly planes in winter can be complicated. However, what Delta’s doing here just doesn’t feel like a winning strategy. The airline reduced Seattle flights to launch Orlando flights. Then the airline canceled Orlando flights to boost Seattle flights. And now the airline plans a puzzlingly large presence in the Seattle to London market, bigger than ever before for winter.

Bottom line

This upcoming winter, Delta will go from operating 3x weekly flights between Seattle and London, to operating 14x weekly flights in the market. It seems that Delta is cutting its Orlando to London flight, and bringing those frequencies to Seattle. On top of that, Delta is likely taking over Virgin Atlantic’s presence in the market as well.

I find this level of service to be a bit of a head scratcher, and if I were a betting man, I’d guess we’ll see some frequency cuts…

What do you make of Delta’s Seattle to London winter expansion? Do you think it will last?