US airports endured a chaotic day on Friday, the worst since the September 11, 2001, terrorist attacks. A failure in the computer system that manages communications forced the Federal Aviation Administration (FAA) to halt all domestic flight operations at airports across the country for nearly five hours. Authorities justified the shutdown by citing “extraordinary circumstances and for safety reasons.” The incident brought airports nationwide to a standstill. By the end of the day, more than 6,500 flights had been canceled and nearly 10,000 delayed, leaving hundreds of thousands of passengers affected by the computer system failure.
Problems with the computer network began at around 3:36 p.m. Eastern time, Transportation Secretary Sean Duffy said hours later. Operators detected “instability” in radar communications at air traffic control centers. The problem emerged “while partial adjustments were being made to the system, incorporating new equipment and technology. However, these components were not adequate. They ended up overloading the old system,” Homeland Security Secretary Markwayne Mullin said at a White House press conference alongside Duffy.
The FAA wasted little time in ordering a nationwide halt to air traffic. More than 3,500 planes were in the air at the time, and the authorities’ priority was to ensure they could land safely.
Mullin ruled out sabotage, cyberattacks or deliberate acts of wrongdoing as the cause of the incident. “There are no indications of suspicious activity. We have found no traces or identified anyone who accessed the system. It appears to have been an automated process,” the Homeland Security secretary said. “However, we are still investigating, so we are not ruling anything out,” he added.
Officials said no flights were ever in danger during the incident and that the shutdown was a precautionary measure. Nearly four and a half hours later, they authorized operations to resume. By then, it was 8:15 p.m. The US aviation system was already in disarray, and it could take days for normal operations to be restored. “It will be a slow process,” said the FAA’s top official. “I think we will be back up and running by the time we reach the peak of Thanksgiving travel,” Duffy said. For now, more than 1,500 flights have already been canceled for Saturday.
A nationwide order grounding all domestic flights is highly unusual in the United States. There have been only two comparable precedents this century: in January 2023, when an outage affected the system that alerts pilots to potential safety hazards; and, most notably, on September 11, 2001, after two planes struck the World Trade Center towers in New York and a third crashed near the Pentagon. On that occasion, authorities closed US airspace for two full days.
Friday’s order brought almost all domestic departures to a halt. Some international flights were allowed to take off, along with aircraft carrying medical supplies and other essential goods. Tens of thousands of passengers were stranded at airports across the country. The exact number of people affected is unknown, but more than two million people pass through security checkpoints at US airports every day, according to the Transportation Security Administration (TSA). Most travelers remained patient, and there were no major incidents. Some passengers who had already boarded their planes were ordered to disembark and return home.
The Trump administration blamed the disruption on outdated technology. “Patching doesn’t work. We need a comprehensive system; we need someone to build the entire system. Trying to put it together through partial fixes doesn’t work, and this is exactly what happens when you do it that way,” Mullin said. “A complete overhaul of the system is necessary,” he insisted.
“It is going to keep failing,” the transportation secretary warned, referring to the decades-old technology that the FAA wants to modernize and whose shortcomings ultimately contributed to the communications failure behind Friday’s disruption. “What we have is an incredibly old air traffic control system,” Duffy said, before using the opportunity to urge Congress to provide new funding for a complete overhaul. “Over the past year, the president has been asking Congress to fully fund the construction of an entirely new air traffic control system.”
Both members of Donald Trump’s Cabinet called for $50 billion in emergency funding to modernize the air traffic control system. The transportation secretary had previously requested an additional $30 billion. “I have asked for $30 billion, and the president has asked for $30 billion. But I want $50 billion,” Duffy said. “What could be more important than having an air traffic control system that actually works?” he added, arguing that the hardware, software and telecommunications infrastructure all need to be replaced.
The officials painted a troubling picture for air travelers: an outdated system in urgent need of modernization, with no guarantees that Friday’s incident will not happen again. This is despite the fact that the Trump administration has already been in office for nearly two years and that Trump previously served a full four-year term.
The Transportation Department unveiled a plan last year to build a new air traffic control system, which is expected to be operational within the next two years. The project is estimated to cost around $31.5 billion, although the Trump administration had already set aside just over $12 billion in funding through the One Big Beautiful Bill Act, passed last year.
Some analysts interpreted Duffy’s remarks as suggesting that the problem stemmed from his efforts to modernize the air traffic control infrastructure. “By doing nothing, you introduce much greater risk into the system,” he said, adding: “I did not anticipate that we would experience an outage like this.”
