What is the distance between two points?
Or, in the case of air travel, what is the distance between two airports?
In the 21st century, such mundane matters are widely assumed to be settled. With modern satellites and GPS systems, highly accurate measurements are easily made.
But a suit brought by a Chicago-based frequent flyer, Hangbo Han, alleges that United has routinely awarded him fewer miles than he actually flew, claiming that United's method of measuring flight distances consistently erred in the airline's favor.
Han's suit cites several specific examples. For instance, he earned 6,920 miles for a United flight between Beijing and Washington, D.C., but claims the "actual flown distance" was 7,276 miles.
It would appear that the dispute hinges on differing definitions of "flight miles."
The distances cited by Han come from the website Flightaware and "other public sources." Flightaware is capable of tracking the actually flown distance for any given flight, including any deviations from the mathematically ideal flight path to avoid inclement weather or circle an airport while waiting for permission to land. Such measurements would meet the strict definition of "flown miles."
United refused to reveal the basis or source for the airport-to-airport distances it uses in awarding miles, citing the pending litigation. But the airline appears to be relying on the idealized and unvarying distance between airports: as the crow flies. That's entirely sensible, given the need to simplify and standardize. But the distances thus measured would more accurately referred to as "computed distance" rather than "flown distance."
Although the discrepancies between the computed and flown distances are typically modest, if Han is successful in gaining class-action status for his complaint, the combined mileage shortfall sustained by millions of program members on hundreds of thousands of flights could be substantial.
Reader Reality Check
Tempest in a teacup, or a serious breach of MileagePlus members' trust?
This article originally appeared on FrequentFlier.com.