Flight durations are a useful proxy for the distances between cities and easily debunk flat Earth. Flat-Earthers invented the “explanations” that the discrepancies of the flight durations in the flat Earth model are caused by winds and jet streams.
In reality, the required wind speed in such a scenario far exceeds the typical jet stream speed. Furthermore, the wind does not affect similar routes the same way in the flat Earth model. And we can easily account for the wind speed differences by averaging the flight durations in both directions.
For example, we can use the nonstop Sydney–Santiago route and the same route but with a stop in Dallas. The route’s duration with a stop in Dallas is almost twice as long as the nonstop route. If it were to occur on a flat Earth, the nonstop route needs to be 900 km/h faster, far exceeding the fastest jet stream.
Furthermore, the nonstop route will fly over Dallas. And both routes should coincide with each other on a flat-Earth. Their jet stream excuse does not work because it affects one, but not the other.
- Sydney–Dallas: QF7, QF8
- Sydney–Santiago: QF27, QF28, LA802, LA803
- Dallas–Santiago: AA940, AA945
- Jet stream – National Geographic