Distance Calculation

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Old Mar 15, 19, 12:28 pm
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Distance Calculation

I know that the distances between city pairs can be different depending on which database a company uses but I find it interesting that DL's calculation changes based on the origin and destination of each flight. Does Seattle get closer to Austin during the daylight and then move further away again at night?

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Old Mar 15, 19, 1:44 pm
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Probably based on routes, if they have to ďconnectĒ with different airports each way. But 4 miles isnít much so thatís strange
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Old Mar 15, 19, 1:57 pm
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To add to the mix, Great Circle Mapper shows the distance as 1,770 miles.
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Old Mar 15, 19, 3:02 pm
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This has come up before and I believe the conclusion was that the miles flown often vary, but the MQM calculator is correct. It calculates 1764 miles in both directions.
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Old Mar 15, 19, 6:21 pm
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Originally Posted by lmsalman View Post
To add to the mix, Great Circle Mapper shows the distance as 1,770 miles.
Recalculate it to AUS.OLD. Delta uses the old airport's location for DEN when calculating MQMs, and I suspect the same is true for AUS. This may explain the dichotomy if they are calculating the return flight from the new airport for that display....

GCMap calculations from SEA show 1770 to AUS but only 1764 to AUS.OLD.
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Old Mar 15, 19, 6:41 pm
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The itinerary view is full of bugs. You will earn the same MQM both ways.
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Old Mar 15, 19, 6:52 pm
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Originally Posted by CKDGM View Post
..........GCMap calculations from SEA show 1770 to AUS but only 1764 to AUS.OLD.
Great insight. However, it doesn't explain how DL got 1768 for AUS->SEA.
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Old Mar 15, 19, 8:01 pm
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All the points make sense and Iím not worried about the mqm earnings. I just find it funny that a flight between 2 points is longer in one direction versus the other. I take off and land at the same airports.
jrkmsp and strickerj like this.
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Old Mar 15, 19, 9:51 pm
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Originally Posted by Worldtraveler727 View Post
All the points make sense and Iím not worried about the mqm earnings. I just find it funny that a flight between 2 points is longer in one direction versus the other. I take off and land at the same airports.
Itís even worse when youíre flying out two airports that are very close. Iím going LGA-JAX, which is listed as 820, then JAX-JFK, which is listed as 869. While on occasion the taxi ride between LGA and JFK seems like it might as well be 49 miles, being on the south shore of Long Island, shouldnít JFK at least be closer to JAX than LGA?
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Old Mar 15, 19, 10:17 pm
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Is it possible they calculate the average distance flown for a segment? I was told this is how they did it at one point . However I have no clue if it is or ever was true. Would make sense though that one direction could have a slightly different length.
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Old Mar 22, 19, 7:24 pm
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Originally Posted by TerryK View Post
Great insight. However, it doesn't explain how DL got 1768 for AUS->SEA.
They measured from the other end of the runway?
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Old Mar 22, 19, 7:29 pm
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AFAIK they use as the crow flies miles or great circle calculations. The actual flight paths shouldn't matter at all, even though airport traffic might well make the distance slightly greater in one direction, or in certain weather conditions, etc......
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Old Mar 23, 19, 9:14 pm
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Originally Posted by flyerCO View Post
Is it possible they calculate the average distance flown for a segment? I was told this is how they did it at one point . However I have no clue if it is or ever was true. Would make sense though that one direction could have a slightly different length.
Nope, itís based on great circle distance. At least, it has been for decades.
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