Nationwide flight restrictions lifted after system failure
The FAA reopened US airspace at 8:15 pm Eastern Time on Friday (1:15 am GMT on Saturday), following a major disruption involving air traffic control communications and radar systems.
Transportation Secretary Sean Duffy confirmed the lifting of the nationwide ground stop but cautioned that flight departures would resume gradually. He said airlines would need time to restore their normal schedules.
"It's going to be slow," Duffy told reporters at the White House.
According to flight-tracking platform FlightRadar24, more than 6,600 flights had been cancelled and approximately 8,600 delayed during the disruption. A further 1,500 flights had already been cancelled for Sunday.
Aviation analysts warned that the consequences of the shutdown could continue for several days, as airlines attempted to reposition aircraft, arrange crew availability and manage passenger backlogs.
Duffy said tens of thousands of travellers had been stranded at airports across the country.
Radar and communication systems become unstable
According to Duffy, the disruption began at approximately 3:36 pm on Friday, when air traffic control centres experienced instability in their radar and communications infrastructure.
Switches and routers responsible for carrying critical operational data became overloaded, resulting in inconsistent information being transmitted through the system. The FAA subsequently decided to halt departures nationwide as a precaution.
Duffy said the agency had not completely lost radar coverage or communications at any point during the incident. Air traffic controllers continued to manage aircraft already in the air, allowing thousands of planes to land safely.
He explained that the decision to stop departures was taken because inconsistent data could compromise the reliability of the system.
The immediate technical problem has since been addressed, and officials said flying was safe. However, Duffy acknowledged that the incident exposed serious weaknesses in the country's ageing air traffic control infrastructure.
More than 6,600 cancellations and hundreds of diverted flights
The ground stop created widespread disruption at major airports, affecting domestic and international travel.
According to aviation analytics company Cirium, at least 827 flights had been diverted during the incident. By 7:05 pm Eastern Time, 670 flights had been returned to their original departure airports, while another 157 had been redirected to different destinations.
Washington Dulles International Airport, Los Angeles International Airport, Cincinnati/Northern Kentucky International Airport and Nashville International Airport were among the destinations receiving diverted aircraft.
Around 11,000 flights carrying more than 1.5 million passengers had been scheduled to depart from US airports after 4 pm Eastern Time on Friday.
Duffy said approximately 3,500 aircraft had been in the sky when the disruption began. The number subsequently fell sharply, with fewer than 400 aircraft remaining in US airspace at the time of his later assessment.
Although the ground stop was lifted, the large number of disrupted flights meant that a return to normal operations would not happen immediately.
Officials say cyberattack has not been established
The incident prompted questions about whether the failure could have been caused by a cyberattack or a malfunction involving artificial intelligence systems.
Homeland Security Secretary Markwayne Mullin said there was no evidence at that stage to suggest that a cyberattack or a rogue AI system was responsible.
He described the problem as appearing to be mechanically driven, while emphasising that investigators were still examining the circumstances.
Mullin said the available information did not indicate any deliberate or malicious activity. However, he stopped short of completely ruling out alternative explanations.
The National Security Agency was assisting the Department of Homeland Security with the investigation.
The administration also maintained that passengers and aircraft had not been placed in immediate danger during the incident. Officials said thousands of aircraft were brought safely to the ground despite the system disruption.
Duffy calls for $50 billion modernisation programme
The outage has intensified debate over the condition of America's air traffic control infrastructure, which has faced criticism over ageing equipment, communication failures and a shortage of several thousand air traffic controllers.
Duffy blamed inadequate congressional funding for delays in modernising the system and called for an investment of $50 billion to upgrade the country's air traffic control technology.
Earlier on Friday, before the disruption, the White House and the Department of Transportation had urged Congress to approve $30.1 billion for improvements to airports and air traffic control infrastructure.
Duffy described the existing system as extremely old and argued that significant investment was necessary to prevent similar incidents.
The administration's position is that newer equipment and technology must be integrated with the existing infrastructure without overwhelming older systems.
Mullin said the installation of new equipment appeared to have placed excessive pressure on outdated technology, contributing to intermittent communication and radar problems.
Duffy, however, acknowledged that he could not guarantee that another disruption would not occur.
Airlines face financial and operational consequences
The disruption is expected to have financial consequences for airlines, with thousands of flights cancelled and schedules thrown into disarray.
Investors reacted to the developments, with shares of American Airlines, United Airlines and Delta Air Lines falling between 1 and 2 per cent in after-hours trading. JetBlue Airways shares declined by approximately 3 per cent.
The operational challenge extends beyond the immediate cancellation of flights. Aircraft and crew members were left in locations different from their planned schedules, making it difficult for airlines to organise subsequent departures.
Officials said the recovery could take several days, although they expected the system to return to normal in time for the Thanksgiving travel rush.
Passengers stranded at airports as uncertainty spreads
Travellers at major airports faced long waits and uncertainty over whether their flights would operate.
At Chicago O'Hare International Airport, passengers discovered the disruption through departure screens displaying widespread delays. Many contacted family members and friends to discuss alternative travel arrangements or whether they should spend the night in the city.
Among those affected was 27-year-old Seattle-based software engineer Amber McQuilkin, who was travelling to New York with friends to attend the League of Legends world finals.
Her friends had already reached their destination, but she was left uncertain about when she could continue her journey. Having taken a week off work for the trip, she considered abandoning the flight and travelling by road, but decided that the alternative would be exhausting.
Other passengers faced similar uncertainty.
Austin Curtis and his wife, travelling from South Bend, Indiana, to Denver for a friend's baby shower, were forced to leave their aircraft after boarding at O'Hare.
They saw luggage being removed from their plane and others, suggesting that the delay could be substantial. The couple had to reconsider whether to book a hotel in Chicago or continue waiting at the airport.
With childcare arrangements already made for their two young children at home, they were also considering the possibility of spending the weekend in Chicago.
Second nationwide ground stop since 9/11
The latest shutdown was described as the longest nationwide aviation ground stop since the September 11, 2001, terrorist attacks.
The only other nationwide ground stop since those attacks occurred in January 2023, when the FAA temporarily suspended domestic departures for approximately 90 minutes following a malfunction in a key computer system.
The latest incident has once again drawn attention to the vulnerability of critical aviation infrastructure and the consequences of technical failures in systems responsible for managing thousands of flights.
While the immediate disruption has been addressed, the investigation and proposed modernisation programme will be crucial in determining how the United States can reduce the risk of similar nationwide interruptions in the future.
