I know a bit about planes and geography and stuff, but I will admit that seeing this on paper in pixels still managed to blow my mind just a little bit.

It concerns the longest commercial flight in the world – namely SQ22 between Singapore Changi Airport (SIN) and Newark Liberty International Airport (EWR) – which is a distance of 16,600km and takes about 18 hours and 45 minutes.

We shouldn’t overlook the return flight (SQ21) either.

The shortest distance between two points on the earth is a straight line, but it it may not be the fastest.

Indeed. And when you’re looking at distances like these, you can make some significant savings on time and fuel by choosing a different route. And not just a slightly different route: a radically different one.

Because EWR and SIN are basically on the other side of the planet from one another, going over the top (the Great Circle Route) is the shortest route between them. As an example, that’s the route most transatlantic flights take, which is why you see LHR-JFK flying over Sheffield, which is basically due North of London, while their final destination, New York, is very much East.

Checking the weather forecasts and using favourable winds might alter the routes of these flights sometimes, but it’s basically a choice of either over the top (via Sheffield) or a straight run across the ocean.

But if you are right on the other side of the world, and going halfway round it, you have a third option – you can go around the other way, as well.

As you can see from the graphic above (borrowed from here), while the first two SQ 22 flights (red and yellow) followed basically the same flight path over the north Pacific (NOPAC) – neither of them were anywhere near the Great Circle Route – the shortest distance between New York and Singapore:

And the first SQ21 (green) followed the GCR very neatly, but the second flight (light blue) went round “the other way” – over the Atlantic.

14 October’s SQ21 took advantage of a strong jet stream across the Atlantic Ocean to fly eastward from New York to Singapore, effectively making the round trip and around the world flight as well. This transatlantic routing shortened the flight time by 3 minutes, but added 945 km to the flight.

Because of Cape Town’s position right at the bottom corner of Africa, there’s really not a lot of variation in the routes of flights that come down here. If there were more any routes to and from here that went across as well as just up and down, that might be different, but everything coming and going here generally follows very set routes from Europe and the Middle East.

Very few flights anywhere in the world have the option to change their routes as entirely as SQ21 and SQ22. When you’re dealing with massive distances, you can make massive changes. So every time you get on, it’s like almost a whole day’s magical mystery tour – but hopefully one with a very clear destination.