Sit on the Left side of the plane for the best views on flights from Seattle to London. While takeoff favors the right side with Rainier and Seattle, the left side wins overall due to the stronger, more scenic Heathrow approach over the Thames and London suburbs, plus consistent visibility of Scottish and English coastline features during descent into the UK.

During takeoff from Seattle Tacoma International (SEA), sit on the Right side for the best views. Departing SEA, flights typically head north then east over the Cascades. The right side offers views of Lake Washington, Seattle's downtown skyline, and Mount Rainier looming to the south. It's a brief but strong scenic opener before the long transatlantic stretch. Notable sights include: Seattle downtown skyline, Lake Washington, Mount Rainier, Cascade foothills.

When landing at Heathrow (LHR), sit on the Left side for the best views. On approach to Heathrow from the west, aircraft often cross the Thames Estuary or fly over west London before landing. The left side typically shows the Thames winding through the city, with recognizable landmarks like the London Eye or Windsor Castle area depending on the approach pattern. Notable sights include: River Thames, Windsor Castle area, west London suburbs, Heathrow's parallel runways.

The flight from Seattle Tacoma International (SEA) to Heathrow (LHR) takes 9h 10m.

The flight crosses the northern Atlantic Ocean, passing near southern Greenland's coastline and the Labrador Sea before making landfall over Ireland or Scotland, both largely obscured by clouds for most of the crossing.