A telecommunications outage affecting regional air traffic control centres disrupted air travel across the United States on Friday, prompting the Federal Aviation Administration (FAA) to order a nationwide halt to flight departures. The outage was traced to a problem with network routers that cascaded across the country, according to the airline source. However, the precise cause of the communications failure remained unclear, with authorities continuing to investigate the incident.
The problem originated with network routers and spread across the country, affecting communications at multiple air traffic control facilities, according to an airline source cited by CNN. The FAA ordered a nationwide ground stop after a telecommunications failure affected all 22 regional air route traffic control centres responsible for directing aircraft across the US. The disruption raised concerns over air traffic controllers' ability to communicate reliably with pilots, prompting the FAA to suspend departures as a precautionary measure. Transportation secretary Sean Duffy said FAA technicians were investigating the communications failure. The agency said the restriction was imposed "due to extraordinary circumstances and for reasons of safety". There was no immediate clarity on when the affected systems would be fully restored. Mullin warned that officials had no definite timeline for resolving the issue and expected the process to take time.
US transportation secretary Sean Duffy said an ageing air traffic control communications system became overloaded and began transmitting inconsistent data, prompting the Federal Aviation Administration (FAA) to impose a nationwide ground stop on Friday. The disruption was caused by overloaded switches and routers in the legacy system, Duffy said at a White House briefing. "Our switches, our routers, actually got overloaded with data... They started to give us inconsistency in the data ... and because of that, we shut the system down," he said, adding that the system experienced intermittent communication and radar failures.
The disruption grounded flights at airports across the country, leaving an estimated 1.5 million passengers stranded, according to an analysis by data firm Cirium cited by CNN. With no clear timeline for restoring normal operations, major US airlines were also considering shutting down flight operations for the evening, an airline source told CNN. US President Donald Trump said the disruption was unlikely to have been caused by a cyberattack or artificial intelligence, while Homeland Security Secretary Markwayne Mullin said there was no indication of a national security threat behind the incident.
US officials said there was no indication so far that the communications failure was the result of a deliberate attack. Trump said the disruption was unlikely to have been caused by a cyberattack or artificial intelligence. Mullin also said preliminary assessments did not point to a national security threat. "This isn’t the same comparison to 9/11," Mullin told reporters outside the White House, adding that all flights had been accounted for and passengers were safe. "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," he said. Preliminary reports also indicated that the incident was not a cyberattack, law enforcement sources told CNN. However, authorities continued to examine the cause of the outage and had not ruled out any possibilities. Mullin also dismissed a connection between the FAA disruption and a major Microsoft services outage reported earlier in the week.
More than 4,000 flights have been cancelled and over 10,000 delayed across the US following the nationwide ground stop. There is still no clarity on when the FAA will lift the restriction and allow normal flight operations to resume. The nationwide ground stop disrupted air travel across the US, with an estimated 1.5 million passengers stranded, according to Cirium's analysis cited by CNN. As flights already in the air continued towards their destinations and landed, the number of aircraft operating across US skies began to decline. With the suspension continuing, airlines faced the prospect of widespread cancellations and delays, while passengers were left uncertain about when they would be able to resume their journeys. An airline source told CNN that major carriers could shut down operations for the evening as the disruption continued.
The impact also extended beyond US domestic travel. Air Canada said flights between Canada, the Caribbean and South America that transit US airspace could also be affected by the disruption.
The FAA and other federal authorities continued working to identify the cause of the telecommunications failure and restore normal operations. However, with no definite timeline for resolution, airlines were preparing for an extended disruption. Passengers were advised to check with their carriers for updates before heading to airports. Trump had been briefed on the situation, while Mullin said the administration was coordinating the response to ensure that officials had the necessary resources. The immediate priority remained restoring communications across the affected air traffic control centres and allowing flight departures to resume safely.
