NEW YORK — The latest round of American Airlines flight cancellations has left tens of thousands of passengers searching for alternative ways to get to their destinations, but airlines are not required to compensate passengers for canceled flights.

The only time airlines legally have to provide compensation is when a passenger is bumped from an overbooked flight, according to the Department of Transportation's Aviation Consumer Protection Division.

However, passengers whose schedules are significantly affected — such as when the only available alternate flight involves flying on a different day or includes an unplanned stopover — are eligible for a refund in lieu of a later flight.

"If they'd rather have a refund than reschedule ... they can demand a refund, even if their ticket is nonrefundable," said Transportation Department spokesman Bill Mosely.

American, the biggest U.S. carrier, has canceled more than 2,400 flights since Tuesday to inspect its MD-80 airliners. The airline has been working to put passengers on alternate flights, but with so many planes out of commission in hubs like Dallas and Chicago, there isn't always enough room for everyone. Other airlines also canceled a handful of flights to inspect their planes.

Passengers who did not buy their tickets directly from the airline might have better luck finding an alternate seat by contacting their online or brick-and-mortar travel agency.

"We can help push that process along and find seats that are available," said Brian Hoyt, a spokesman for Orbitz Worldwide Inc., the parent company of, and other sites.

American was offering travel vouchers to some inconvenienced passengers and putting some travelers in hotels. The carrier, based in Fort Worth, Texas, said customers who were forced to stay overnight because of cancellations should e-mail the carrier's customer-relations department through a form on the company's Web site for details about compensation.