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Left or right? The simple geometry that decides your view

"Which side of the plane should I sit on?" sounds like a question about luck or insider knowledge. It isn't. It is a compass problem with an exact answer, and once you see the trick you can estimate it in your head for any flight on Earth.

The one rule

Stand in the cockpit and look down the nose. Anything whose compass bearing is less than the plane's heading (up to 180° less) is out the left window; anything whose bearing is greater is out the right. That's the entire rule. A plane flying heading 090° (due east) has north (000°) on its left and south (180°) on its right. Everything else in this guide is just applying that subtraction to the sun and to landmarks.

Applying it to the sun

The sun's position is perfectly predictable: at any moment it sits at a known compass bearing (its azimuth) and height above the horizon (its altitude) for any point on Earth. In the northern hemisphere's mid-latitudes it rises roughly in the east, tracks through south at midday, and sets roughly west - "roughly" because the rise and set points swing north in summer and south in winter, by a lot at high latitudes.

Combine that with your heading and you get the classic results:

Why the date changes the answer

The same flight number can flip sides across the year. A June evening departure from London has the sun setting in the north-west; in December it sets in the south-west - nearly 90° of difference. On a north–south route, that swing can move the sunset from one side of the aircraft to the other. It's why the route pages on this site show a season-by-season table rather than one answer, and why we ask for your date and departure time instead of just the route.

Applying it to mountains and cities

Landmarks follow the same subtraction, with one extra step: the plane moves, so the bearing to a fixed landmark changes through the flight. Mont Blanc might be 30° right of the nose when you pass Geneva and behind the wing twenty minutes later. What matters is the bearing at the moment of closest approach - which requires knowing where along the route the plane is at each minute. That, plus a database of things worth seeing, is essentially what our engine computes; the how-it-works guide has the full pipeline.

The great-circle surprise

One more wrinkle: long-haul flights don't fly the straight line you'd draw on a wall map. They fly great circles - the genuinely shortest path on a sphere - which look curved on flat maps. New York to London arcs far north over Nova Scotia and toward Ireland; Dubai to Los Angeles passes near the Arctic. The practical consequence: the plane's heading changes continuously along the route, so the sun can migrate from one window to the other mid-flight even though you're "flying east" the whole time. On routes like that there is no single correct side - there's a correct side per phase, which is why verdicts here are broken into takeoff, cruise and landing.

Cheat sheet

Or skip the arithmetic: enter your flight and get the computed verdict with the sun, glare and landmarks all weighed for your exact date.

More guides

Or just check your own flight - enter a route, date and departure time and get a left/right verdict in a second.