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Major airlines are complying with the Federal Aviation Administration's call to reduce flight schedules starting Friday, with some carriers already beginning to cancel flights. But in an interview with ABC News, United Airlines' chief customer officer, David Kinzelman, said most travelers will be unaffected by the small number of cancellations, and the airline is aiming to have the least amount of impact on its passengers. “We are going to cancel about 4% of our schedule in certain markets over the next several days,” Kinzelman said. "The good news here for customers is we're getting those cancellations in today for tomorrow through Sunday. That will help customers who might be traveling over the weekend to be able to look for alternatives during that course. And keep in mind, it's select cancellations through select markets. United's a large airline, so we are confident that we'll be able to reaccommodate customers and still meet their travel needs," Kinzelman added. Delta Air Lines said it has already canceled around 170 of its flights for Friday. The airline says it expects the number to be lower on Saturday due to the low travel volume. American Airlines plans to cancel 220 of its 6,000 flights each day through the weekend and has already begun to notify passengers. Best Advice Experts say the best advice is to download the airline's app so you can be easily notified and rebooked if your flight is canceled. Morning flights are also the least impacted by cancellations and delays; additionally, they allow more time to find an alternate flight if there is an issue. International flights will not be impacted American, Delta and United have stressed that their long-haul, international flights will not be impacted by the flight cuts. The airlines are also saying that flights between their hubs are also not expected to be impacted. What does this mean? If you are flying from Newark Liberty International Airport to Chicago O'Hare International Airport on United or Ronald Reagan Washington National Airport to Dallas Fort Worth International Airport on American, or vice versa, those flights are not expected to be impacted as they are hubs for United and American Airlines. United Airlines says it will be making “rolling updates” to its flight schedules as the shutdown continues to help notify travelers in advance and minimize disruptions. Delta said it plans to notify travelers at least a day in advance of any cancellations, similar to how the airline operates during a weather-related cancellation. All three airlines have also waived their flight change and cancellation fees and are allowing customers to get a refund if they choose not to fly during this time. How are airlines deciding which flights to cut? United is trying to cut flights where it operates multiple flights at different domestic airports, according to Kinzelman. The reductions are happening after the summer travel rush and before the peak holiday travel period, which will allow airlines to prevent mass cancellations. Where could we see those cuts? The majority of cuts are anticipated to be on regional flights. These are flights operated between smaller airports and major hubs on small planes. Planes like the Bombardier CRJ are most commonly used on regional flights, which can typically seat between 50 to 80 passengers. What might airlines do? To accommodate a larger volume of passengers, airlines might swap out smaller planes for bigger planes like the Boeing 787or Boeing 777. These bigger planes can fit double and even up to five times more passengers on a flight compared to smaller planes like the CRJ regional jet. The bigger aircraft are generally operated on long-haul and international flights. However, aviation experts warn that the flight reductions will result in a travel mess. "It's going to be heavily chaotic because the FAA and DOT are giving airlines only 48 hours to start to make these changes," Henry Harvedelt, president of Atmosphere Research, told ABC News. "I believe what will also happen is we'll see changes on Friday differ from those made on Saturday. The airlines may change the schedule again on Sunday. So it's going to be really, really chaotic and hugely, hugely disruptive for the traveling public." In a LinkedIn post, which has since been deleted, Frontier Airlines CEO Barry Biffle advised travelers to book a backup ticket on another carrier to avoid being stranded at an airport. "Don’t book a basic ticket. For example, book Economy on Frontier so you can reuse the ticket value as changes are free or you can get a credit. If your flight is cancelled your chances of being stranded are high so I would simply have a backup ticket on another airline," Biffle posted. These reductions come as Airlines for America, an airline trade group, projects a record high of 31 million people to fly over the Thanksgiving holiday period between Friday, Nov. 21, and Monday, Dec. 1.