How GeoKnow works

Last updated 26 October 2026

Great-circle distance

The Earth is a sphere, so the shortest path between two airports is an arc, not a straight line on a flat map. That arc is the great-circle route, and it is why a flight from London to Los Angeles curves up towards Greenland on a flat map. GeoKnow calculates it from each airport's latitude and longitude with the haversine formula and a mean Earth radius of 6,371 km.

Why real flights are longer

Real flights follow air traffic routes, jet streams, weather and airspace restrictions, so they are usually longer than the great-circle distance. The games ask about distance, not flying time.

Not every pair is a real flight

Routes are pairs of major airports. Some are flown nonstop, and some are not offered by any airline. GeoKnow compares geometry and does not claim a scheduled service exists.

Aircraft drawings

Plane Spotter draws simplified plan views from each aircraft's published length, wingspan and wing shape, all at one scale. They are approximate and leave out details such as winglets.

Countries on the map

Overflown uses the Natural Earth 1:110m world map, which is in the public domain. A country counts as flown over when the great-circle path spends more than about 60 km over it. The map is simplified, so very small countries are missing, and borders are approximate.

Populations

Population Match uses rounded estimates for around 2024.

Corrections

If you spot a mistake, please tell us.