Sit on the Left side of the plane for the best views on flights from London to Seattle. While the right side wins at Heathrow departure, the left side delivers the more spectacular sustained experience. Once over Canada and the Pacific Northwest, the left side tracks the Rocky Mountains and then the Cascades on approach, culminating in the Mount Rainier view on landing. The Heathrow departure view on the right is brief; the mountain scenery on the left lasts far longer.

During takeoff from Heathrow (LHR), sit on the Right side for the best views. Heathrow's dominant departure runway is 27L/27R, heading west. On a westbound departure, the right side gives you a clear view of central London as the aircraft banks right over the city. You'll see the Thames snaking through the urban grid, with the City of London and Canary Wharf tower clusters clearly identifiable. Notable sights include: River Thames bends through central London, Canary Wharf tower cluster, Windsor Castle and Great Park to the southwest, M25 orbital motorway arc.

When landing at Seattle Tacoma International (SEA), sit on the Left side for the best views. SeaTac primarily uses runways 16L/16R for southbound arrivals, meaning the aircraft approaches from the north heading south. The left side faces east, giving you a direct view of the Cascade Range including Mount Rainier, which at 14,411 feet is unmissable on a clear day. Elliott Bay and downtown Seattle are also visible to the left during the approach. Notable sights include: Mount Rainier (Cascades), Elliott Bay and downtown Seattle skyline, Lake Washington, Mount Baker on the northern horizon.

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

The great circle route from LHR to SEA tracks northwest over Scotland and the Hebrides, then across the North Atlantic near Iceland and southern Greenland (Greenland ice sheet visible on clear days), over Baffin Island and Hudson Bay, across the Canadian Shield and boreal forest of Manitoba and Saskatchewan, over the Canadian Rockies in Alberta and British Columbia including the Columbia Icefield area, then descending over the Cascades into Seattle. Greenland's ice sheet and the Canadian Rockies are the two most visually dramatic midpoint features.