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Airports in Dallas and Houston are among those that will see flight cuts by the Federal Aviation Administration to reduce air traffic beginning Friday amid the ongoing government shutdown. DFW, Bush International, Hobby and Love Field among those facing reduction What we know: The FAA announced it would reduce air traffic by 10% at 40 "high volume" markets beginning on Friday. The reduction was prompted by staffing shortages because of the ongoing government shutdown, which is now the longest in U.S. history. Among those markets, four Texas airports are expected to see reduced flights: Dallas-Fort Worth International and Love Field in Dallas; and George Bush Intercontinental Airport and William P. Hobby Airport in Houston. The backstory: Transportation Secretary Sean Duffy told "Fox & Friends" on Thursday that the decision to limit air travel capacity to 40 airports was "data-driven." "We were seeing increased pressure in these 40 markets. And we looked at the data — this was data driven — and so taking 10% of the flights out will reduce that pressure, which is what we want to do," Duffy said. "Now, does that mean there's going to be no delays? No, Brian," Duffy told Fox News' Brian Kilmeade. "There's potentially still going to be delays if we have staffing triggers, and we don't have enough controllers in an aerospace where we did cut 10%, you might see additional delays." Airlines react to flight reductions Dallas-based Southwest Airlines released a statement saying they are evaluating the planned reductions and would communicate with customers "as soon as possible." What they're saying: "Nothing is more important to Southwest® than the safety of our customers and employees," the airline said. "We know that these FAA-imposed cancellations can impact an important moment in your life. We appreciate your understanding." Southwest said it would notify customers through the contact information given about flight cancellations and that most customers will be automatically rebooked on another flight. The company said refunds would be available for canceled flights that are not rebooked. Another North Texas airline, Fort Worth-based American Airlines, said they expect most travelers to be unaffected by the reduction. What they're saying: "We expect the vast majority of our customers’ travel will be unaffected, and long-haul international travel will remain as scheduled," American Airlines said in a statement. "As schedule changes are made, we’ll proactively reach out to customers who are impacted. As always, we encourage all customers to check their flight status on aa.com or the mobile app, which will provide real-time updates." American is also offering customers an opportunity to change flights or request refunds. "In the meantime, we continue to urge leaders in Washington, D.C., to reach an immediate resolution to end the shutdown," American Airlines said. "We remain grateful to the air traffic controllers, TSA officers, CBP officers and other federal employees who are working right now without pay — all to get our customers where they need to be safely — as well as our American Airlines team members who always work to take the best care of our customers." United Airlines released a statement about the reductions on Wednesday: "The FAA's goal is to relieve pressure on the aviation system so that we can all continue to operate safely. That is the FAA's highest priority, and ours as well. No matter what environment we're operating in, we will not compromise on safety. These reductions will start on Friday, November 7, and we will continue to make rolling updates to our schedule as the government shutdown continues so we can give our customers several days' advance notice and to minimize disruption for them and for all of you," the company said. Read the full statement here. Flight delays during shutdown Dig deeper: This week, more than 1,000 flight delays within, into or out of the U.S. have been delayed, with dozens of flights canceled, according to the flight tracking siteFlightAware.com. As of 9:30 a.m. ET on Thursday, 1,094 flights within, into or out of the U.S. had been delayed, while 49 had been canceled, according to FlightAware.com. Air traffic controllers have been working unpaid since the shutdown started on Oct. 1. Most employees work mandatory overtime six days a week, affecting their time to perform side jobs to cover bills and other expenses. RELATED: FAA cuts flights amid shutdown — What to do if yours is delayed or canceled Airlines work to have at least 80% of their flights depart and arrive within 15 minutes of when they are scheduled. Aviation analytics firm Cirium said that since the shutdown began, the total number of delays overall has not fallen significantly below that goal because most of the disruptions so far have been no worse than what happens when a major thunderstorm moves across an airport. Major airlines, aviation unions and the travel industry have been urging Congress to end this shutdown as soon as possible by voting to support the clean funding resolution that Republicans have proposed.