interline

In addition to partnerships like code shares, when an airline operates a flight on behalf of another, or alliances, most airlines also have relationships known as interline agreements that allow them to transfer passengers to flights on other carriers.

Charles Leocha, president of Travelers United, a nonprofit passenger advocacy group, agrees, saying: “I would like to see more interline agreements. That would be a big help.”

“Now, if a carrier cancels a flight, you miss a funeral or a wedding, you are out of luck. With an interline agreement, consumers are not put in that untenable situation.”

The interline agreement idea was among 17 proposed rule changes listed in a June 24 letter to Buttigieg by Flyersrights.org, a nonprofit passenger rights group with more than 60,000 members.

Interline agreements were common before the industry was deregulated in 1978 and have now fallen out of favor, especially among low-cost airlines whose pricing models differ so much from those of traditional carriers that they avoid such agreements, according to industry experts.