Flight delayed or canceled? If so, these are your rights and what the airline owes you.

Airlines are assailed with complaints every time there is a spike in flight cancellations and delays, and every time, too many passengers are left bewildered, unsatisfied or even fuming at airlines' responses.

There is a disconnect between what passengers think they are owed and what airlines owe them when flights plans go haywire thanks to a patchwork of federal regulations and airline policies.

Some rules, like those covering refunds for cancellations and significant flight delays by the airline, are dictated by the U.S. Department of Transportation. Others, like hotel and meal vouchers and expense reimbursement, are up to individual airline policies spelled out in dozens of pages of legalese known as a contract of carriage.

"In Europe it's uniform. In Canada it's uniform. In the United States, you are at the mercy of the contract of carriage,'' said William McGee, an aviation adviser to Consumer Reports who has been pushing for an air passenger bill of rights for years and last year joined other consumer advocates in taking their case to Transportation Secretary Pete Buttigieg. "In the past 20 years, those contracts have gotten much harder to read, they've gotten lengthier, and they've gotten much weaker from a consumer standpoint.''

What's a stranded traveler to do? Know your rights and persistently pursue them, including taking airlines to task on social media.

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What happens if your flight is canceled?

Airlines are required by the DOT to offer a refund when they cancel a flight. It doesn't matter if the reason for the cancellation was outside their control, like weather, or within their control, like maintenance issues or flight crew shortages. And it doesn't matter what kind of ticket you bought, including nonrefundable tickets or basic economy tickets.

Airlines prefer, of course, to automatically rebook you on their next available flight, but you are under no obligation to take it. Keep in mind, though, that a refund a) might not be instant and b) probably won't cover the cost of a new last-minute ticket unless your original ticket was pricey, so the next-available flight might be the least-expensive option for getting to your destination or back home when things go awry last minute.

If you opt for a refund, you are eligible to get your money back, not just a travel credit or voucher. Airlines are quickest to offer those, so travelers who want their money back instead often have to take some extra steps. Southwest and Delta, for example, automatically issue travel credit, so travelers who want their money back have to request it.

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What happens if your flight is delayed?

The same DOT rules apply to significant delays, meaning passengers are eligible for a refund regardless of the cause of the airline's delay. The only wrinkle here is that airlines' definitions of "significant delay" vary. American offers refunds for delays exceeding 90 minutes, Delta, Spirit and Alaska two hours, for example.

Will an airline pay for a hotel?

Here's where things get trickier and involve those contracts of carriage. Airline policies generally state that they only pay for a hotel if the flight cancellation or overnight delay is their fault, and then only if you don't live in the city you're stranded in. The earlier you request one, the better, as airport hotels sell out quickly when there's flight cancellation mayhem.

Weather, of course, and air traffic control issues are outside of airlines' control, so passengers whose flights are scrubbed for those reasons generally aren't given free hotel stays. (Many airlines do offer discounted hotel rates for those impacted by weather cancellations, so be sure to ask.)

How do you know the reason for your cancellation?

"I think passengers, quite frankly, have a right to be suspicious,'' McGee said. "Airlines are not forthcoming on a lot of issues like this.''

At the same time, the former airline flight dispatcher says passengers often don't understand how weather across the country can have a ripple effect on an airline.

Savvy travelers should jot down gate announcements or conversations with employees about the reasons for the delay as well as screenshot any alerts sent about the delay via text or the airline's mobile app to plead their case for reimbursement if the airline denies hotel accommodations due to weather.

Can an airline rebook you on another airline?

Stranded passengers are free to check options on other airlines, but whether the airline that canceled the original flight picks up the tab is another question.

Most major airlines, with the notable exception of Southwest, have so-called interline agreements with competitors so they can easily transfer passengers over when they don't have room. But airlines prefer to keep travelers on their flights, so the option isn't usually offered upfront.

Will the airline reimburse you for meals?

As with hotel stays, meal vouchers also are generally only doled out when cancellations and long delays are caused by the airline, but it never hurts to ask in any situation. Some airlines, though, including Delta and Southwest, have been known to roll in snack carts or order pizza during extreme weather and other situations outside their control.

Don't expect the airline's money to go far at the airport, airport hotel, or area restaurants, if you can find one open. The going rate is $12 per passenger at American and Alaska, for example. Delta says meal money varies by city. Some airlines, including American, say the vouchers can be used for food delivery services like UberEats.

This article originally appeared on USA TODAY: Flight cancellations, delays: Travelers' rights, what airlines owe you