Article: How Does Qantas Calculate Distances?

[AFF Editor]

When Qantas recently announced its new BNE-MNL route, I looked up the distance on Great Circle Mapper and was pleasantly surprised to find it would be 3,596 miles - just low enough to put it into "Zone 4" on the Qantas Classic Flight Reward table.

Turns out it's actually in Zone 5. I wanted to understand why, which led me down a bit of an unexpected rabbit hole that involved learning the difference between a sphere and an ellipsoid.

You can read about it here:

How Does Qantas Calculate the Distance Between Airports?

There's more than one way to calculate the distance between two airports. It makes a difference to the number of Qantas points needed for Classic Flight Rewards on routes like Brisbane-Manila.

www.australianfrequentflyer.com.au

 

[bussyboy]

Interesting, probably a lawsuit waiting to happen - “the shortest distance on the surface of the globe" has all kinds of interpretations!

 

[jrobin]

...

How Does Qantas Calculate the Distance Between Airports?

There's more than one way to calculate the distance between two airports. It makes a difference to the number of Qantas points needed for Classic Flight Rewards on routes like Brisbane-Manila.

www.australianfrequentflyer.com.au

It is all very interesting that there is more than one way to calculate distances.
But does QANTAS at least use the same method for earning points on flights as for redeeming points?

 

[justinbrett]

I checked my flight planning software and it calculates the route as 3134 nautical miles, which is 3606.5 statute miles.

I would hazard a guess aviation planning systems use legacy calculations which would have used the simpler sphere model.

This route is particularly affected as it is primarily north south within a similar longitude. The difference is 9 nautical miles. However comparing the distance on SYD LHR the difference is only 3 nautical miles even though it’s a much longer route.

 

[oz_mark]

Back in the day, before things became simpler and fairer, Qantas used to award points based on distance flown. Using various flights, I was able to match what they were doing to one particular ellipsoid model (I think I found about three of them at the time, that all gave slightly different answers)