What to Know About Friday’s Nationwide Ground Stop

LatestHere’s the latest.The nationwide ground stop that brought all air travel to a halt across the country and stranded thousands of passengers has been canceled, according to the Federal Aviation Administration.Within minutes of flight traffic being restored, Sean Duffy, the transportation secretary, took to a podium Friday night at the White House to decry Congress, accusing lawmakers of dragging their feet when it came to fully funding upgrades he warned were vital to prevent similar failures from happening again.“It’s going to continue to fail,” Mr. Duffy told reporters, adding: “How many times does this have to happen for Congress to give the money to fix it?”Mr. Duffy added that the antiquated radar and telecoms systems that controllers rely on to transmit data and other information between facilities began to falter at 3:36 p.m. The aging system, which has undergone a number of upgrades, became overloaded, officials said.Appearing alongside him, Markwayne Mullin, the secretary of homeland security, stressed that there was never any indication that the communications failures had been triggered by a cyberattack, but he added, “we are still looking, and we’re not going to rule it out.” He emphasized that lives were never in danger.But the incident appeared to inject new fuel into Mr. Duffy’s now monthslong campaign to secure at least $30 billion in extra funding for air traffic control modernization.Last year, Congress approved $12.5 billion to upgrade aging air traffic facilities and technology, funds Mr. Duffy has repeatedly referred to as a “down payment” when asking for tens of billions more. On Friday night, Mr. Duffy appeared to up the ante, telling reporters that he didn’t just want another $30 billion for the project, but another $50 billion. He argued that it should be delivered in emergency funding before the end of the year, after which control of Congress — and the budget — switches from Republicans to Democrats.Some Democratic lawmakers have already raised questions about how efficiently and effectively the F.A.A. has spent the money they have been given thus far. But Mr. Duffy has long argued that his department cannot be expected to complete a meaningful overhaul of the nation’s air traffic control system without a massive influx of funding.Friday’s nationwide ground stop was only the third that the F.A.A. has issued this century. It ranks as the second-longest, after the ground stop issued on Sept. 11, 2001, in the wake of the terrorist attacks on the World Trade Center in New York. There was a shorter one on Jan. 11, 2023, because of an outage in the F.A.A.’s system to alert pilots to safety issues.The order on Friday halted nearly all departures and stranded thousands of passengers at airports across the country. Hundreds of flights were diverted to other airports and more were canceled, even as some internationally bound flights managed to secure permission to take off. Amid the delays and cancellations, many passengers were taken off flights or told to go home.More than 2 million people pass through airport security checkpoints on a typical day, according to Transportation Security Administration data. On Thursday, the agency screened nearly 2.5 million people. According to FlightRadar24, an aviation tracking site, there were more than 1,000 airborne aircraft bound for U.S. airports during the nationwide ground stop. According to the flight tracking app Flighty, there were more than 30,000 departures and arrivals scheduled for the remainder of the day.Passengers waiting to take off Friday afternoon were stuck in limbo.In the Denver airport, passengers were taken off their flights with their suitcases. A handful began rebooking travel for the next day. But most waited patiently for any kind of update. A Southwest flight attendant announced that the airline expected an update in 30 minutes.Before the advisory was published, the F.A.A. halted flights to Chicago’s O’Hare and Midway airports, citing equipment problems, and reported equipment-related departure delays at Newark, Las Vegas, Teterboro, Orlando, Houston and Phoenix.Here’s what else to know:If your flight is canceled: You are entitled to a refund if your flight is canceled in the United States, regardless of the reason, or if a flight is significantly delayed or changed and you decide not to take it. Here are other travel tips that might be helpful. Read more ›A busy travel month: The ground stop happened about two weeks before Thanksgiving, one of the busiest times of the year for air travel. On average, U.S. airlines are expected to fly about 2.7 million passengers each day over the holiday period, according to industry trade group Airlines for America.Handling the chaos: Radio transmissions between air traffic controllers and pilots at major airports offered a peek at how they navigated the ground stoppage. Read more ›The last ground stop: The last nationwide ground stop came in the early morning of Jan. 11, 2023, and lasted around 90 minutes. The disruption came after a system to alert pilots of real-time dangers went down. Read more ›Christine Chung, Niraj Chokshi, Luke Broadwater, Dustin Volz, Lisa Lerer and Robert Chiarito contributed reporting.What to Know About Friday’s Nationwide Ground StopImagePassengers at Ronald Reagan Washington National Airport on Friday.Credit...Alex Kent/The New York TimesThe Federal Aviation Administration issued a rare nationwide ground stop Friday afternoon, after outdated air traffic communications equipment became overloaded with data and began to fail, officials said.The outage stranded thousands of passengers and caused widespread delays from which airlines and airports are still struggling to recover. It also highlighted persistent vulnerabilities in the aging U.S. air traffic infrastructure and a funding fight, as administration officials demanded lawmakers approve tens of billions of dollars more to accelerate systemwide upgrades.Here’s what to know.What caused the problem?Sean Duffy, the transportation secretary, told reporters at the White House Friday night that the radar and other air traffic communications started to falter at 3:36 p.m. when old routers became overloaded with data. While the failures were not universal, they were pervasive enough to prompt officials to issue the unusual nationwide moratorium on takeoffs, Mr. Duffy said.Appearing alongside him at the White House, Markwayne Mullin, the homeland security secretary, stressed that there was no evidence that nefarious activity had triggered the technology failures.“We’ve seen zero evidence that this was a cyberattack,” Mr. Mullin said, suggesting that new equipment and new technology the Mr. Duffy’s department had added to the old infrastructure was what had overwhelmed it.Mr. Duffy insisted that the failure was caused by the antiquated, legacy communications equipment, not recent upgrades to the system.“What we have is an incredibly old air traffic control system,” Mr. Duffy said, predicting that until significant upgrades are made, “it’s going to continue to fail.”How long will it take to get things back to normal?Mr. Duffy warned that it would take “some time” for air travel nationwide to recover from the ground stop, predicting flight schedules would be fully back to normal by the time the Thanksgiving travel season begins.“I believe that it’s going to take us some time to get back to capacity,” he said, adding: “We’re going to have some makeup to do.”Mr. Duffy said that the F.A.A. would prioritize larger commercial flights ahead of private and charter flights, to get previously grounded flights off the ground.ImageGrounded planes at San Francisco International Airport on Friday.Credit...Erin Schaff/The New York TimesWhat does the administration say needs to be done?Mr. Duffy has long been pushing for a sweeping overhaul of the U.S. air traffic infrastructure, routinely complaining that controllers have been hampered by the country’s failure to upgrade outdated equipment.“We have old, old switches, old routers — we use 1980s little copper lines,” he said to reporters Friday. Only last week, the F.A.A. announced that it had begun to phase out the use of floppy disks.Last year, Congress approved $12.5 billion to fund upgrades to the country’s aging air traffic facilities and networks, some of which has been directed toward communications system upgrades. Mr. Duffy noted Friday that air traffic facilities that had been upgraded to digital systems did not experience the same overloading issues that prompted the F.A.A. to issue the ground stop order.But he stressed that having an air traffic control system dependent on a “patchwork” of upgrades and fixes was untenable, calling on Congress to spend tens of billions more to allow for more upgrades.Why did Duffy blame Congress?For months, Mr. Duffy has been calling on the Republican-controlled Congress to give his department another $30 billion to accelerate efforts to upgrade air traffic control systems. On Friday night, he upped the ante, telling reporters he wanted $50 billion — and that he wanted it before the end of the year.“This is an emergency, I want Congress to give us emergency funding,” he said, adding: “How many more times does this have to happen for Congress to give the money to fix it?”But it is unclear whether Republicans will prioritize such a sum before the end of the year, after which control of Congress shifts to the Democrats, who are expected to scrutinize how the F.A.A. has utilized air traffic funding they have received so far. Republican lawmakers have filed bills in the House and Senate to authorize $30 billion in air traffic upgrades, but neither piece of legislation has cosponsors.Later on Friday, Representative Hakeem Jeffries of New York, the House’s top-ranking Democrat, appeared to reject Mr. Duffy’s accusing tone and shifted the blame back to the Trump administration.“Today’s unprecedented breakdown is the latest in a series of unacceptable air travel incidents under the Trump administration’s failed leadership,” he said in a statement, adding that “American travelers deserve timely answers from the Trump administration about how and why this happened and assurances that steps are being taken to ensure that our air travel system remains safe and functional.”AdvertisementSKIP ADVERTISEMENTNationwide, more than 8,200 flights — or over 31 percent of those scheduled in the United States for Friday — were canceled, according to Cirium, an aviation data firm. And the disruption was already spilling over into Saturday, usually a slower day for travel, with more than 5 percent of flights canceled before the day had even begun.The ground stop stranded some Democratic leaders in Denver.ImageFormer Transportation Secretary Pete Buttigieg at a summit in Denver on Friday.Credit...Mark Makela/Getty ImagesPete Buttigieg could not believe what he had just watched. The former transportation secretary stood at the corner of the hotel bar in Denver, where CNN had just finished broadcasting the Trump administration’s news conference about the ground stop that stopped flights nationwide on Friday.Mr. Buttigieg was among the thousands of Democrats who had gathered in Denver this week for a conference designed to chart the party’s future and celebrate their midterm wins. The ground stop stranded some of the party’s top rising stars and their staffs.People accustomed to having inside information suddenly had very little.At a table to Mr. Buttigieg’s left sat Gov. Abigail Spanberger of Virginia, Gov. Mikie Sherrill of New Jersey and Senator Elissa Slotkin of Michigan. They munched on Parmesan fries and checked their phones as they waited for news of their flights.To his right, Senator Raphael Warnock of Georgia scanned his Senate group chats to check for updates from secure channels and Senator Mark Warner of Virginia.But Mr. Buttigieg, glancing up at the television, struggled to comprehend the performance of his successor, Secretary Sean Duffy.“You can just write down the comic book asterisk swearing characters,” Mr. Buttigieg said when a New York Times reporter asked for his impressions of the news conference. “I have questions.”The downtown hotel bar resembled the famous bar scene in “Star Wars.” The stranded politicians bemoaned the lack of information from the federal government and their inability to get home.One New England-based operative booked a rental car and planned to drive back to Boston. Others looked up how many hours it would take to get to the East Coast on Amtrak. (The answer: more than 40.) Aides to one prominent Democratic governor, who had flown to Denver on a private jet, fielded questions from others in the bar about whether they could hitch a ride home.A few people working for Gov. JB Pritzker of Illinois — who did not come to Denver — commandeered a long table where Anne Caprara, his chief of staff, worked two phones as she juggled rumors, emergencies back home and calls from the boss. She said Mr. Pritzker was furious about the lack of information coming from the Trump administration.“Welcome to Denver’s hottest bar, the Mos Eisley Cantina of politics,” Ms. Caprara said, referring to the “Star Wars” bar. “With ‘Veep’ characters and a ‘Terminator 2’ vibe.”Shane Goldmacher contributed reporting.Representative Hakeem Jeffries of New York, the leader of the House Democrats, shifted the blame for Friday’s ground stop back to the Trump administration. In a statement, he called the stop “the latest in a series of unacceptable air travel incidents under the Trump Administration’s failed leadership.”Earlier Friday night, Sean Duffy, the transportation secretary, had blamed Congress for not adequately funding his department’s plans to upgrade the nation’s air traffic infrastructure.“American travelers deserve timely answers from the Trump Administration about how and why this happened,” Mr. Jeffries added.AdvertisementSKIP ADVERTISEMENTPilots and air traffic controllers kept communicating during the outage.ImageRonald Reagan Washington National Airport on Friday.Credit...Alex Kent/The New York TimesA communications outage on Friday led the Federal Aviation Administration to pause departing flights nationwide, but pilots were not entirely cut off from federal air traffic controllers.In a Friday night news conference, Transportation Secretary Sean Duffy said the outage was intermittent, so federal controllers were still able to reach pilots.“It wasn’t a complete blackout in communication or radar,” he said. “So we were able to keep some of those communications going.”But even in a complete outage, aviation authorities have multiple backups to maintain contact with pilots.Pilots and air traffic controllers primarily communicate by voice radio, using primary, backup and emergency frequencies.Controllers and airline dispatchers can also send text-based messages to pilots. And many commercial planes are equipped with satellite communications, which are especially useful for reaching people on the ground when the planes are flying in remote airspace like over the ocean.If a control tower loses radio capabilities, it can also communicate with pilots with high-intensity colored lights, which pilots can acknowledge by rocking their wings or flashing lights in response.Airlines began to restore some flights after the nationwide stop was lifted. United Airlines said that while many of its flights had been canceled, some were still expected to operate. American Airlines said it was prioritizing flights to non-hub airports and international destinations in order to get planes and crews in place to recover quickly. Southwest Airlines said it was resuming a “limited number of flights” on Friday.The ground stop has scrambled travel plans for sports teams across the country.ImageSan Francisco International Airport on Friday.Credit...Erin Schaff/The New York TimesSome professional and college sports teams were stuck on runways, or opting to pile into buses, ahead of games this weekend that are now uncertain due to the nationwide ground stop that was lifted Friday night.Markwayne Mullin, the secretary of homeland security, said at a news conference on Friday that the ground stop was caused by technology upgrades “overwhelming” the flight communication system. Thousands of flights have been canceled, but no high-profile games have been affected so far, ahead of what is set to be a busy weekend in sports.Dozens of teams had made it out of airports just ahead of the stop. But the N.B.A.’s Brooklyn Nets were not so lucky.The Athletic reported that the Nets were stuck on a team plane on Friday. They have a game Saturday night against the Memphis Grizzles.Also stuck at an airport was the University of Texas Longhorns football team, slated to play Louisiana State University in Baton Rouge, La., on Saturday night. Minutes before the stoppage, the Longhorns posted a video of players boarding a plane with the caption “Bayou bound.”Both teams are in the Southeastern Conference, which said in a statement that it would work “to determine whether any adjustments to scheduled competitions become necessary.”On Friday night, Transportation Secretary Sean Duffy told reporters that he encouraged college football teams to coordinate their flights with the Federal Aviation Administration “to make sure we have games going off tomorrow.”While some teams, including the Longhorns, headed home from the airport to wait out the delay, a handful of others opted to travel the old-fashioned way: By bus.The Athletic reported that among the longest drives was a 330-mile ride for the Purdue University Boilermakers, who are playing the University of Iowa Hawkeyes on Saturday night.The University of Southern California women’s basketball team said they were grounded in Los Angeles ahead of a marquee game Sunday against the University of South Carolina Gamecocks, but were preparing to travel on Saturday.In men’s college basketball, a Saturday game between University of North Carolina Greensboro and Cornell University in Ithaca, N.Y., was postponed because of the ground stop.N.F.L. teams typically travel on Saturday for Sunday games. Five teams told The Athletic that their travel plans were not affected.According to The Athletic, the stakes of the ground stop may be most significant for the National Women’s Soccer League, which is scheduled to hold its semifinals this weekend. The stop affected the Kansas City Current’s flight to New York City ahead of its game against Gotham FC on Sunday. The Utah Royals, playing the Washington Spirit on Saturday, traveled before the stoppage.The N.B.A.’s Cleveland Cavaliers had planned to catch a flight home after their Friday night game in Miami. Kenny Atkinson, the Cavaliers head coach, told reporters before the game that he didn’t know if the team would make their flight.“I think we’re scrambling to find hotel rooms in case,” Mr. Atkinson said, adding: “If not, we’ll sleep on the bus.”AdvertisementSKIP ADVERTISEMENTHear how air traffic controllers grappled with the ground stoppage chaos.ImagePlanes sitting idle at Ronald Reagan Washington National Airport after the F.A.A. grounded all flights nationwide.Credit...Alex Kent/The New York TimesRadio transmissions between active pilots and air traffic controllers at major airports offer a peek at how they navigated the Federal Aviation Administration’s nationwide ground stoppage on Friday.An air traffic controller at Newark Liberty International Airport can be heard sharing the news with pilots.Minutes later, at airports in Atlanta and Chicago, controllers said they had limited information.As planes landed over the next hour and departures were stuck at their gates, air traffic controllers can be heard talking about significant gate issues and comparing the tarmac to a “parking lot.”Amid the chaos, one pilot noted the date while talking to a Newark controller: “It’s not lost on me that it’s Friday the 13th.”Passengers groaned loudly as an announcement at Newark Liberty International Airport ordered them back to their gates for both domestic and international flights. “Are you kidding me? When will this end?” one woman cried out.ImageCredit...Eduardo Munoz/ReutersAt Kennedy International Airport in New York, passengers waited to board a flight to Paris that was delayed because the pilot hadn’t been able to take his flight from Boston to J.F.K. Instead, he decided to drive, and passengers have been receiving updates about his E.T.A. over the loudspeaker. The latest update said he was expected to arrive at the airport at 9:45 p.m. When it was announced that the flight would begin boarding before his arrival, one woman raised both hands over her head with her fingers crossed. AdvertisementSKIP ADVERTISEMENTMore than 6,600 flights on Friday had been canceled by 9:30 p.m. Eastern, according to Flight Aware, a flight-tracking service. And that disruption had already spilled over into the weekend, with about 1,500 flights on Saturday canceled as well.ImageCredit...Alex Kent/The New York TimesPete Buttigieg, who served as the transportation secretary during the Biden administration, is stranded in Denver and mingling in the bar at the Ritz-Carlton hotel. After watching the Trump administration’s press conference, Buttigieg seemed exasperated. “You can just write down the comic book asterisk swearing characters,” Buttigieg said. “I have questions.” It could take days for air travel to fully normalize after an event of this scale, said Vikrant Vaze, a Dartmouth professor specializing in commercial aviation logistics. “It’s going to take a lot of gymnastics” to get every airline’s aircraft, passengers and crew members back in the correct positions, he said. Some contingency measures can be taken by airlines to get things back on track, such as flying reserve crews or “ferrying” an empty aircraft. It’s helpful that airlines have the nighttime hours, when there are typically fewer domestic flights, to push through some of the backlog, Vaze said.Cheers and applause erupted in the Delta Sky Club at Los Angeles International Airport, where travelers just heard an announcement that the nationwide ground stop had been lifted. At least three Delta flights at the airport were already boarding, but it could take some time for other flights to get going, a Delta agent said in the announcement.AdvertisementSKIP ADVERTISEMENTThe White House briefing by the cabinet secretaries is now over.Transportation Secretary Sean Duffy appeared to suggest that his effort to upgrade air traffic control infrastructure may have contributed to the outage, but he defended the upgrades by arguing that they had to be done.“By doing nothing, you inject way more risk into the system,” he said, adding, “I didn’t anticipate that we would have an outage like this.”Duffy has criticized Congress throughout this briefing for not allocating more funding to air traffic infrastructure.“I can’t build things if I don’t have money,” Duffy said, shaking his head. “We should talk to our senators and members of Congress to say, ‘We don’t deserve this.’”ImageCredit...Tierney L. Cross for The New York TimesSean Duffy has been clamoring for another $30 billion in air traffic modernization funds from Congress for several months now. On Friday night, he appeared to up the ante, saying he didn’t want just $30 billion — he wanted $50 billion. But the official ask, which he has made repeatedly and which is reflected in legislation he has endorsed, is another $30 billion.In the last few weeks, Republicans in the House and Senate filed bills to give Duffy that $30 billion. Neither has any co-sponsors.AdvertisementSKIP ADVERTISEMENTAsked if travelers should expect disruptions to their Thanksgiving travel plans, Sean Duffy said he thought flights would be “back up and operational as we come into the heat of travel” ahead of the holiday.In the aftermath of a frightening air-traffic control technology failure that affected Newark Liberty International Airport in April 2025, Duffy argued that the nation’s air-traffic control systems were outdated and in need of a $12.5 billion upgrade. Tonight he is using the latest technology failure as an argument for another huge increase of funding.Homeland Security Secretary Markwayne Mullin said that new technology upgrades overloaded the existing, antiquated system, “overwhelming” the existing equipment.“It’s going to continue to fail,” Transportation Secretary Sean Duffy said of the antiquated technology that the F.A.A. was trying to upgrade, triggering the telecom failures that prompted the nationwide ground stop.The question of older F.A.A. systems ceasing to work has been a constant throughout Duffy’s tenure as transportation secretary, going back to disputes he had with Elon Musk about what type of technology could be used for backup systems.The Congress that Duffy has been criticizing has been entirely in Republican hands for the last two years. It’s now about to switch to Democratic control.AdvertisementSKIP ADVERTISEMENT“Our fix gives us a pretty good indication that it was a legacy network problem that went down,” Transportation Secretary Sean Duffy said, hinting at the origins of the crisis. He said the problem was related to old equipment being overloaded.Duffy and Mullin were asked if they could say with “100 percent certainty” that this was not the result of a cyberattack or rogue artificial intelligence. “There’s nothing certain right now,” Mullin said. “It doesn’t appear that way.”“I want Congress to give us emergency funding,” Transportation Secretary Sean Duffy said, calling on lawmakers to give the Trump administration another $30 billion, at least, to pay for further upgrades to air traffic control infrastructure. But some lawmakers have raised questions about how the F.A.A. has managed the funds it has been given thus far.Transportation Secretary Sean Duffy said the Federal Aviation Administration reopened airspace at 8:15 p.m. Eastern. But he said that flight departures would be slow, and he urged passengers to check with their airlines.ImageCredit...Marco Bello/ReutersAdvertisementSKIP ADVERTISEMENTSpeaking at a White House briefing, Transportation Secretary Sean Duffy said there were limits to how quickly flights could begin moving again tonight. “Hopefully tomorrow, we are going to start to see far better movement,” he said.AdvertisementSKIP ADVERTISEMENTAdvertisementSKIP ADVERTISEMENTAdvertisementSKIP ADVERTISEMENTAdvertisementSKIP ADVERTISEMENTAdvertisementSKIP ADVERTISEMENT