A question that occurs to me: are you looking only at commercial flights?
If so, a commercial airline has to have enough passengers to make the flight profitable. Are there enough people that travel from Johannesburg to Sao Paolo, for example, to make a direct flight viable, or do they need to fly to a major hub such as London in order to have enough passengers to make it pay?
For example, all the commercial flights from my local airport fly to a metro hub. There's a larger town that I drive to semi-regularly about 150 miles away. If I wanted to fly there via commercial airline , I would have to fly to the metro hub (~250 miles), then change planes to fly 160 miles to get to that town. It's simply the economic factors that determine that.
Now if a person hired a charter to fly from Johannesburg to Sao Paulo, and was taken via London, that would be very compelling.
There would certainly be SOME flights taking that direct route. If you could fill a plane with people from one place to another, it would not only save on fuel, but it would be a major competitive advantage vs. other carriers in terms of the convenience and the time of travel. Based on the number of flights, there would certainly be a business case for at least one direct flight. This pattern of flights is just too darn consistent to be based on economics.
So, I recall when I was a child and took a few flights over a couple years between Cleveland and Hungary (direct flight always with a full plane). We always flew over Gander Air Force Base in Newfoundland. After checking out a globe map, I asked my dad why that was, since that did seem to be really out of the way vs. a direct line. He told me that regulations required that passenger planes always remain within a certain distance of land. Not sure if he heard that somewhere, but I have since learned that this was entirely untrue. While this route is not as bad as the Southern Hemisphere routes, if you plot a direct line between Cleveland and Hungary on a flat earth map, it's dead on a straight line between the two.
EDIT: So I looked it up and it still show on a map as taking that route. Again, not extremely pronounced, since there's much less of a difference in the Northern Hemisphere. But still ... why? Why would you take this curved route when you could just make a straight line ... and save some time and some fuel?
https://tinyurl.com/mr3vpcasPut this on an FE map and it's a straight line.
Topic: % Confidence in Earth's Shape (Read 89604 times)