Air travel across the United States was thrown into disruption on Friday after the Federal Aviation Administration (FAA) ordered a nationwide halt to flight departures, citing a telecommunications outage affecting regional air traffic control centres.
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Administration → throw → centres
The unprecedented move grounded flights at airports across the country and disrupted travel plans for thousands of passengers, including people heading home, attending weddings and travelling for weekend events.
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move → ground → events
The FAA said the restriction was imposed “due to extraordinary circumstances and for reasons of safety”.
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restriction → say → safety
The ground stop was the first nationwide suspension of flights since January 2023, when a key FAA computer system malfunctioned, and only the second such order since the September 11, 2001, attacks.
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system → malfunction → attacks
Homeland security secretary Markwayne Mullin said the outage appeared to be a telecommunications problem and that officials had no indication it was the result of an attack.
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it → say → attack
However, the precise cause remained under investigation, with authorities examining the communications systems used by air traffic controllers.
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authorities → remain → controllers
Here is what we know so far about the disruption, its possible cause and its impact on passengers.
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know → know → passengers
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Trump rules out cyberattack, AI as US probes nationwide flight disruptionWhy did the FAA ground flights across the US
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FAA → rule → US
The FAA ordered the nationwide ground stop after a communications problem affected the 22 regional air route traffic control centres responsible for directing aircraft travelling between airports.
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problem → order → airports
Transportation secretary Sean Duffy said FAA technicians were investigating the issue.
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technicians → say → issue
The agency described the decision as a safety measure, saying flights could not continue departing normally while the communications systems were affected.
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systems → describe → measure
According to an airline source cited by CNN, the FAA told carriers that the outage was caused by a problem with network routers.
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outage → accord → routers
The issue was believed to have originated at Chicago Midway International Airport before spreading across the country.
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issue → believe → country
The FAA was reportedly unable to provide a clear explanation of the problem during initial crisis discussions, with different facilities experiencing its effects in different ways.
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facilities → provide → ways
The ground stop meant aircraft could not take off, while planes already airborne were allowed to continue towards their destinations and land.
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planes → mean → destinations
Officials said they were handling flights still in the air on a case-by-case basis.
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they → say → basis
Is the outage linked to a cyberattack or security threat?
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outage → link → cyberattack
US officials said there was no indication so far that the disruption was caused by a deliberate attack.
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disruption → say → attack
US President Donald Trump said that the nationwide flight disruption was unlikely to have been caused by a cyberattack or artificial intelligence, as authorities investigated the telecommunications outage.
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authorities → say → outage
Mullin told reporters at the White House that the problem was a telecommunications outage and not, based on the information available at the time, a hostile act against the country.
"There was no indication as of yet this was a nefarious attack against us," he said.
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he → tell → us
He added that officials were still investigating what had caused the outage and cautioned against making assumptions before the findings were available.
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findings → add → assumptions
He said there was no indication of a national security threat or deliberate attack.
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He → say → threat
"This isn’t the same comparison to 9/11," he told reporters, adding that all flights had been accounted for and passengers were safe.
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passengers → tell → reporters
"There is no indication that we’ve had, no reason to believe, that as of right now this was a threat to the United States," Mullin said, describing the incident as a telecommunications outage.
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Mullin → be → outage
He confirmed that Trump had been briefed and was coordinating with Transportation Secretary Sean Duffy and other officials.
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Trump → confirm → Duffy
CNN, citing law enforcement sources, reported that preliminary assessments did not point to a cyberattack.
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assessments → cite → cyberattack
A senior US security source later told the broadcaster that multiple law enforcement and intelligence agencies, including the FBI, Department of Homeland Security and National Security Agency, were examining the incident.
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agencies → tell → incident
The investigation was continuing to examine how the government's aviation systems connect to networks that could potentially be exposed to malicious actors.
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that → continue → actors
The senior security source said there was still no indication of an attack.
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source → say → attack
Mullin also said officials were not ruling out any possibilities at the early stage of the investigation.
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officials → say → investigation
Are the problems linked to the new FAA AI system or Microsoft outage?
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problems → link → system
Officials initially considered whether the FAA's nationwide rollout of a new artificial intelligence-supported system could have contributed to the disruption.
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rollout → consider → disruption
The system, known as SMART, analyses flight schedules, weather forecasts and other data from a location near Washington, DC.
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system → know → Washington
It then sends recommendations to the FAA's command centre and air traffic controllers.
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It → send → centre
However, the system does not directly operate the regional air traffic control centres affected by Friday's communications outage.
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system → operate → outage
In a statement, ASI, the company that designed the system, said, "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."
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stop → design → FAA
Mullin said officials had no indication that the new system was responsible for the disruption.
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system → say → disruption
He also said the outage was not connected to the major Microsoft services disruption reported earlier in the week.
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outage → say → week
Microsoft separately said it had no indication that the FAA's nationwide ground stop was related to any of its services.
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stop → say → services
How many flights have been affected
The disruption led to cancellations and delays at airports across the country, with further problems expected as the ground stop continued.
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stop → affect → country
…and 57 more, not listed.