Originally Posted by
SPN Lifer
Note that because of the 500-mile minimum credit per segment for MileagePlus Premier members, this overstates the actual BIS mileage, but is what UA uses. So that's good enough for me.
It's ok, the great circle distance isn't a true measure of the actual BIS mileage either, it would have to be specific flight path dependent in 3D space. I just irrationally "rationalize" that the 500-mile minimums are a way to recover some of that lost miles spent circling around airports, taxiing in the runway, diversions from programmed path, etc.