The US Federal Aviation Administration on Friday lifted a nationwide grounding of departing flights, after a communications failure at air traffic control centers caused chaos at airports and led to the longest nationwide grounding since the attacks of September 11, 2001.
US Secretary of Transportation Sean Duffy announced the lifting of the ban, which affected millions of Americans, as of 20:15 EST (01:15 GMT).
But Duffy told reporters that the closure had a ripple effect, and that the problems would continue for days.
On Friday, the US Federal Aviation Administration issued a nationwide decision to stop aircraft taking off “for exceptional circumstances and safety reasons,” after it had previously reported serious problems with air traffic control communications.
The Flight Radar 24 website reported that more than 4,700 flights had been canceled and another 10,000 delayed, on Friday, while another 700 flights had already been canceled on Saturday.
Aviation sector analysts said that airlines may need days to restore their flight schedules after a nationwide halt that lasted more than four hours.
The Department of Homeland Security said there were no indications of a cyberattack behind this malfunction.
"Very old system"
US Secretary of Transportation Sean Duffy said that the air traffic control system was "very outdated" and provided a timeline showing the sequence of events of the incident.
Duffy reported that at 3:36 PM local time, “we experienced instability in radar systems, communications and control centers” across the country. As soon as inconsistent data was detected coming from the routers, the Federal Aviation Administration issued a decision to stop all flights nationwide.
“What we have is a very outdated air traffic control system,” Duffy told reporters at the White House, explaining that the routers were subjected to “data overload,” which led to “inconsistency” in the information received from them.
He added that Congress must "provide the necessary resources to build an advanced and modern air traffic control system," noting that it needs $50 billion to modernize this system.
Last year, Congress approved $12.5 billion in funding to modernize the agency's outdated communications system.
On Friday, the Federal Aviation Administration and the White House asked Congress to allocate another $30.1 billion to deal with other problems.
Flight Aware indicated that about 7,000 flights in the United States were delayed or canceled due to the suspension of flights nationwide.
The malfunction represents the latest and most dramatic sign of the strain on America's air traffic control system, which has been plagued by equipment and communications problems, a shortage of controllers and an aging infrastructure.
Before circulating the decision to stop departing flights on Friday, the administration stopped air traffic in Chicago due to problems with air traffic control communications.
“All departing aircraft must remain parked in place until further notice,” the administration added. The administration explained that international flights will be dealt with on a case-by-case basis.
The administration has not yet responded to a request for comment.
US Secretary of Homeland Security Markwayne Mullen said that what is happening is not a repetition of the September 11 attacks, but rather a failure in communications and the situation is completely different, stressing that there is no reason for citizens to fear or worry about their traveling relatives.
He added: "President Trump took the lead in dealing with the crisis as soon as it occurred and provided us with the resources and means of communication necessary to move quickly."
“There were no prior indications and there is still no evidence to suggest that the communications failure was caused by an intentional attack,” Mullen said.
The administration indicated that the suspension of flights across the country was due to disturbances in air traffic control frequencies and radar systems.
For his part, US Secretary of Transportation Sean Duffy said when the suspension of flights began that “the ground stop at all airports within the country was due to a defect in communications with air traffic control centers,” noting that the Federal Aviation Administration was investigating the problem.
During the suspension period, planes in the air were able to land, while planes on the ground were not allowed to take off.
The biggest stoppage since the September 11 attacks
This is the second nationwide decision to stop all departing flights since the attacks of September 11, 2001. The other decision was in January 2023, when the authority stopped all domestic flights departing for less than two hours.
