Delta Air Lines asks more than 10 out of every 10,000 passengers to voluntarily surrender their seat and take a later flight, making it the major U.S. carrier most likely to “bump” passengers, the Chicago Tribune reported March 30, 2017.

United Airlines and Southwest Airlines were other carriers that frequently bumped travellers in 2016, respectively shifting an average of 7.7 and 7.2 of every 10,000 passengers to different flights, according to an analysis of U.S. Department of Transportation data. The research was conducted by, which reports on airline credit card and rewards programs.

The report includes US airlines that have at least one percent of total domestic scheduled-service passenger revenues and operate aircraft with a passenger capacity of 30 or more seats, and provides system data for scheduled passenger service on domestic flights and data on international flight segments that originate in the United States.

Travellers are most likely to get bumped (15.9 per 10,000 passengers) from flights on smaller, regional airlines. Most passengers gave up their seats willingly, the report found: only 8.3 percent of those who got bumped did so involuntarily. Overall, the rate at which airlines bumped passengers declined 40 per cent between 2010 and 2016.

Bumping typically occurs when airlines oversell flights to avoid flying with empty seats due to no-shows, or when they are forced to switch to smaller planes due to delays or equipment problems. The airlines with the lowest bump rates, JetBlue, Frontier, and Hawaiian, benefit from serving far more leisure travellers than business travellers, who are more apt to change their travel plans with little notice, said Delta spokesman Anthony Black.