US authorities lift nationwide flight ground stop after 4-hour disruption

The US Federal Aviation Administration (FAA) on Friday lifted its order suspending flights across American airspace, allowing air traffic to resume from 8:15 p.m. local time after a technical fault in radar and communications systems halted flights for several hours.

Flights have restarted nationwide, but it could take several more days for schedules to return to normal.

According to reports by international media, an abnormality was detected in the country’s air traffic control system at about 3:36 p.m. on Friday. With problems emerging in radar, communications networks and control centers, the FAA decided to temporarily halt all takeoffs for safety reasons. The move disrupted flights at airports across the United States and left thousands of passengers stranded.

Transportation Secretary Sean Duffy said the situation arose because of excessive strain on the aging technology used to control air traffic. He said older routers and switching systems in particular struggled to cope with the heavy volume of data, causing inconsistencies in the exchange of information between control centers. However, he said the problem had not caused the radar or communications systems to fail entirely.

Duffy said the FAA’s control centers had resumed operations after the ban was lifted, but that it would take time for flight schedules to fully normalize. The effects of aircraft diverted to other airports, and of flights canceled or delayed, could linger for several more days, he said. Plans for flight operations are being reworked in coordination with airlines to manage the situation.

Duffy also underscored the need for major funding to modernize the country’s air traffic control system, saying reliance on technology that is decades old is creating the risk of such crises. The administration has asked Congress for an additional $30 billion to overhaul the sector’s infrastructure.

Separately, Homeland Security Secretary Markwayne Mullin said preliminary investigations found no evidence of a cyberattack or sabotage in the incident. He said it was also unconnected to the recent Microsoft technical outage.

Aviation analytics firm Cirium said at least 600 flights had to land at alternate airports during the ban. Cargo and international flights, as well as passenger services, were disrupted at airports across the country, with passengers at New York, Chicago, Denver and Washington airports particularly affected.

In January 2023, flights across the United States were halted by a fault in the FAA’s NOTAM (Notice to Air Missions) system. This is the first time since then that such a ban has been imposed simultaneously at all of the country’s airports.