The US Federal Aviation Administration said in a statement that the nationwide halt to departures, and delays to landings, at all US airports that began at about 4pm ET on Friday was caused by “a temporary telecommunications outage”.
“Every flight has been accounted for and international flights will be handled on a case by case basis,” the FAA added.
Here is what we know about the rare nationwide “ground stop” issued by the FAA.
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There is, as of now, no sign that the “telecommunications outage” that led to the sudden halt to all departures at US airports has been fixed.
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It remains unclear what caused the outage, but, according to Markwayne Mullin, the former Oklahoma senator now leading the Department of Homeland Security, “there is no indication … that this was a nefarious attack”.
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There have been 10,343 flight delays within, into or out of the US so far, according to the website FlightAware, and 1,479 cancellations.
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This is just the second nationwide ground stop of all departures since the 11 September 2001 attacks. The previous one came in January 2023, when the FAA paused all domestic departures for less than two hours.
Donald Trump remained uncharacteristically quiet about the crisis at US airports on Friday, posting about other matters but making no mention of what his administration is doing to fix the problem that has thrown travel into chaos.
Democrats have filled the vacuum, demanding answers.
Congresswoman Nellie Pou, a New Jersey Democrat who serves on the House aviation subcommittee said in a statement:
“I do not want to speculate the cause of this crisis right now but this is a massive, almost unprecedented disaster impacting tens of millions of Americans. We are nearing the holidays. The Trump administration must be prompt and forthright in providing answers. More generally, I would note this constitutes yet another crisis in the American skies under the Trump administration. Just this week, the GOP majority cancelled a hearing next week with the head of the FAA. Something must change. The American people are owed transparency, and the incoming Congress must seek a full accounting of how air traffic modernization is being implemented and what remains to be done to keep our airspace safe.”
Some international flights have been able to depart from New York City’s John F Kennedy international airport, Boston’s Logan airport and Philadelphia’s international airport, according to airlines and data from Flightradar24.
Among the flights now in the air are a Delta flight from New York City to Rome, which departed at 6.23pm ET, an SAS flight to Copenhagen that took off a few minutes ago, as well as an Air France flight to Paris and a Virgin Atlantic flight to London.
A British Airways flight from Philadelphia to London departed three minutes early, at 6.32pm local time.
Flights have also departed for Europe from Newark international airport in New Jersey, and Washington’s Dulles international.
There are signs that the nationwide halt to departing flights has eased, at least for some international destinations.
San Francisco international airport confirmed in a statement in the last 30 minutes that “Pacific-bound flights are now cleared to depart from SFO, including destinations in Hawaii and Asia”.
The US National Weather Service has been forced to dispel misinformation spreading online, and from some news services, that its radar system went down on Friday.
“In case you heard otherwise, there is no radar outage and https://radar.weather.gov is fully operational!” the service said in a social media post. “Outdated content from isolated webpages stating otherwise has been circulating, but NWS radars are operating normally.”
The “temporary telecommunications outage” that caused the US Federal Aviation Administration to ground all departing flights on Friday just before 4pm ET appears to be a disruption of radio frequencies used by air-traffic controllers to communicate with pilots, the Wall Street Journal reports.
Here is what unnamed sources told the Journal:
The outage appears to be affecting a telecommunications network overseen by L3Harris Technologies, according to people briefed on the matter. The network handles crucial radio frequencies that air-traffic controllers use to communicate with pilots, the people said. It wasn’t immediately clear whether the outage also affected the radar feeds that controllers use to keep aircraft safely separated in the skies.
Moments after Markwayne Mullin, the homeland security secretary, stumbled through a media briefing at the White House on Friday, in which he made it clear that the Trump administration did not yet know what had caused the telecommunications outage that paralyzed the nation’s airports, congressional Democrats demanded to know: “What the hell is going on?”
In a statement on social media in response to Mullin’s briefing, Democrats on the House homeland security committee argued that “Trump and his cabinet are completely out of their depth. Their incompetence, secrecy, and recklessness are putting Americans in danger – and they can’t even clearly explain to the American people what’s happening.”
Meanwhile, the Republican-led Senate commerce committee, chaired by Ted Cruz, sought to cast the blame more widely, noting that no new air route traffic control centers have “been built since LBJ was in office”.
American travelers trying to book last-minute trains on Amtrak have reportedly experienced error messages on the rail service’s website and app, and difficulty reaching representatives on the phone. “We’re currently experiencing higher-than-normal call volumes due to ongoing airline issues,” Amtrak said in a statement on social media.
ASI, a Boston-based frontier AI company that was awarded an $875m software and AI contract in June by the Federal Aviation Administration wants everyone to know that its new air traffic management tool, known as Smart, which was deployed in September, is not to blame for the nationwide outage on Friday.
“The current ground stop is not based on or a result of the Smart system, any product of ASI or our integration with FAA and ATC,” the company said in a statement posted on social media.
In September, Sean Duffy, the former Fox News host leading the US Department of Transportation, starred in a social media video promoting the deployment of the Strategic Management of Airspace, Routing, and Trajectories, or Smart, system.
“We’re here to move at the speed of Trump,” Duffy said in the video. “We’re leading the world in new technology.”
The FAA said in a statement on Tuesday that the new Smart system was activated at all 22 air route traffic control centers in the US “to reduce delays, reduce fuel consumption and improve the travel experience for the flying public”
The US Federal Aviation Administration said in a statement that the nationwide halt to departures, and delays to landings, at all US airports that began at about 4pm ET on Friday was caused by “a temporary telecommunications outage”.
“Every flight has been accounted for and international flights will be handled on a case by case basis,” the FAA added.
Here is what we know about the rare nationwide “ground stop” issued by the FAA.
-
There is, as of now, no sign that the “telecommunications outage” that led to the sudden halt to all departures at US airports has been fixed.
-
It remains unclear what caused the outage, but, according to Markwayne Mullin, the former Oklahoma senator now leading the Department of Homeland Security, “there is no indication … that this was a nefarious attack”.
-
There have been 10,343 flight delays within, into or out of the US so far, according to the website FlightAware, and 1,479 cancellations.
-
This is just the second nationwide ground stop of all departures since the 11 September 2001 attacks. The previous one came in January 2023, when the FAA paused all domestic departures for less than two hours.
Nearly 7,000 flights across the United States were delayed or canceled on Friday, according to flight-tracking service FlightAware. Planes already in the air have been allowed to land, Reuters reports, but those on the ground could not take off.
The disruption is the latest and most dramatic sign of strain on a US air traffic control system beset by equipment and communications failures, controller shortages and ageing infrastructure.
The FAA’s ground stop order, halting departures from all US airports, runs through at least 11pm ET Friday.
Speaking to reporters outside the White House on the nationwide ground stop at all US airports, the US homeland security secretary, Markwayne Mullin, said: “Just to make sure we understand, there is no indication, and we had no reason to believe as of right now, that this was a threat to the United States. This was a telecommunication outage throughout FAA.”
The secretary added that there was no evidence “yet that this was a nefarious attack; it is just a telecommunication outage, as of right now”.
Asked whether it might have been caused by AI or a cyber-attack, Mullin incorrectly said that the last nationwide groundstop was “on 9/11” and sought to reassure the families of travelers that this outage was not part of a terrorist attack. “There is no reason to be concerned about your loved ones if they’re flying,” he said.
“As we investigate what caused this, you always got to assume that as many cyber-attacks that take place, that you make that assumption – so, but as of right now, that’s not known.”
After restoring communications so all airborne flights can land, Mullin said, “we’re going to continue to work to find out what the root of the cause is”.
“We’re not ruling out anything at this point,” Mullin added.
As we wait for clarity on what caused the nationwide groundstop of air travel to and from all US airports, you could do worse than read this weekend’s New York Times Magazine cover story from James Fallows, a veteran journalist and pilot about whether the US air travel system “is eroding margins of safety”.
Reports are steadily coming in from airports around the US, where passengers are confronting the sudden halt to all air traffic due to an as-yet-unexplained communications failure.
The Guardian’s own Tom Johnson, our head of audience development, sends along this dispatch from Ronald Reagan Washington national airport, known as DCA.
Hundreds of passengers wait for news in a packed terminal at Ronald Reagan Washington national airport. Gate agents, along with most travelers in the terminal, refreshed their phones looking for updates, and attempted to change their flights. Nearly every seat is filled, with some people sitting on the floor and using their luggage as makeshift desks for their laptops.
The exact cause of the nationwide air traffic control crisis in the US is not yet known, but, as our colleague Marina Dunbar reported, last week the Federal Aviation Administration announced that the first digital air traffic control towers in the US were officially operational, bringing new technology first to smaller airports in Florida and Alaska as the Trump administration presses ahead with updating the country’s aviation infrastructure.
The digital towers use advanced camera systems and digital displays to give air traffic controllers a continuous, 360-degree view of airport operations, including runways, taxiways and surrounding airspace, according to the agency.
The nationwide paralysis of the US air traffic control system, causing thousands of scheduled flights to be grounded and thousands more to be unable to land, has prompted a wave of anecdotal reports from passengers at airports.
This is just the second nationwide ground stop of all departures since the 11 September 2001, attacks. The previous one came in January 2023, when the FAA paused all domestic departures for less than two hours, Reuters reports.
Last year, Congress approved $12.5bn to fix the FAA’s ageing communications system, and on Friday the FAA and White House asked Congress for another $30.1bn to address other issues.
According to the tracking website Flightradar24, there are currently “3,100 airborne aircraft bound for US airports amid nationwide ground stop”.
In addition to the grounding of all flights at US airports due to a communications issue affecting air traffic control, the US Federal Aviation Administration advised all airborne flights to circle along predetermined routes instead of landing, due to “equipment outages”.
The US transportation secretary, former Fox News host Sean Duffy, has confirmed that all flights are grounded at US airports “following a communication issue impacting all Air Route Traffic Control Centers”, in a statement posted on social media.
“FAA technicians are investigating the issue,” Duffy added. “We will provide immediate updates as we have them.”
Duffy’s post on the social media platform X appeared beneath one he pinned in late September, which includes a video of himself touting the introduction of a “new air traffic management tool that saves YOU time, cuts back DELAYS, and makes your flying experience BETTER”.
The US Federal Aviation Administration on Friday issued a national ground stop “due to extraordinary circumstance and reasons for safety” after the agency earlier reported serious air traffic control communications issues, Reuters reports.
Shortly before the nationwide announcement, the FAA first halted traffic in Chicago due to air traffic control communications issues. An agency notice posted on its website said: “All departing traffic should remain groundstopped until further notice.” The FAA said international flights will be managed on a case-by-case basis.
