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.

Dreamliner drawing

I tweeted about this while it was happening last week, but it’s worth recording on here for those who didn’t see it, and for me to come back here in a few years and go “Oh yeah – remember that?”.’s blog has the full story, but tl:dr – a Boeing 787 did a test flight over the USA, the route of which drew an outline of a giant Boeing 787.

This was during an ETOPS test on the Rolls Royce Trent 1000 TEN engine.

I had to look up what ETOPS meant, and found that it was “Extended-range Twin-engine Operational Performance Standards”. Basically, it refers to the distance that a twin (or more) engined plane is allowed to go from an airport that it can safely land at, in case of engine failure. As with many of these sorts of things, it’s actually rather more complicated than it would seem to need to be.

Still, as long as the people in charge know what’s going on, I suppose…

Regulators closely watch the ETOPS performance of both type certificate holders and their affiliated airlines. Any technical incidents during an ETOPS flight must be recorded. From the data collected, the reliability of the particular airframe-engine combination is measured and statistics published. The figures must be within limits of type certifications. Of course, the figures required for ETOPS-180 will always be more stringent than ETOPS-120.

Pfft. Of course…

Unsatisfactory figures would lead to a downgrade, or worse, suspension of ETOPS capabilities either for the type certificate holder or the airline.

And so they should. Excellent.