Discrepancy Between CO Calculation and DL Calculation of Miles Earned
 

I recently flew CO and was earning DL Skymiles for the flight. It was EWR-TPA and back. On my CO ticket, it represented that the mielage for the flight was 1,010 miles. However, when credited to my Skymiles account, it was registered as only 998 miles.

Anyone know why there is a discrepancy between what CO shows on the ticket and what is deposited into my Skymiles account both as miles and MQMs?

Being based in Atlanta, Delta SkyMiles are really Delta DixieMiles and thus slightly shorter than Continental miles. If you take into consideration the Southern Drawl, those DixieMiles are stretched out a little bit longer and end up the same as Continental's.

Delta calculates mileage based on a Mercator projection, whereas Continental relies on a Cassini projection.

Thanks, this will be useful for all of you who call and complain :mad: about it. ^

How did you know that? I am impressed.

I thought the difference was due to CO circling the airport prior to landing :D

Actually I was thinking the two hour taxi times at EWR. Thanks for the information. I think they should say something on the mielage credit area of DL.com.

Perhaps I'm missing something, but the Mercator projection would give really inaccurate results. Perhaps you mean [Universal] Transverse Mercator?

Maybe they should use the aircraft's odometer reading. ;)