The FAA halts departing flights across the US after a communications failure hits all its air traffic control centres

A nationwide ground stop

The Federal Aviation Administration grounded all departing flights across the United States on Friday after a communications failure hit the centres that manage the country’s airspace, France 24, Al Jazeera, the South China Morning Post and US tech outlets reported. Planes already in the air could land, but those on the ground could not take off.

“The FAA issued a nationwide ground stop for all US airports following a communication issue impacting all Air Route Traffic Control Centres. FAA technicians are investigating the issue. We will provide immediate updates as we have them.”

Sean Duffy, US transportation secretary, France 24(translated)

The FAA said on X that there had been a “temporary telecommunications outage” and that all flights were being halted as a precaution, with international flights handled case by case, Al Jazeera reported. Its notice cited “extraordinary circumstances” and “reasons of safety”, and said the halt would stay in place until at least 11pm Eastern time, according to the Post. Shortly before, the agency had stopped traffic in Chicago over communication problems, France 24 said.

Thousands of flights hit

The flight-tracking service FlightAware said nearly 7,000 flights had been delayed or cancelled soon after the order, and the Guardian later put the figure at nearly 11,000. Some 4,042 flights were in the air heading to US airports when the stop was ordered, according to Flightradar24, cited by Al Jazeera.

The outage affected all 22 Air Route Traffic Control Centers, which guide aircraft across the country, Al Jazeera said.

Looking for the cause

The homeland security secretary, Markwayne Mullin, told reporters there was no indication that the stop had been triggered by a threat to the US.

“Everybody’s safe. The flights are accounted for. This is not another 9/11.”

Markwayne Mullin, homeland security secretary, Al Jazeera English(translated)

Asked whether the planned rollout of a new AI tool to help air traffic controllers could be to blame, Mullin said officials had not ruled it out. The FBI does not believe a cyber-attack or criminal activity caused the failure, Bloomberg reported, citing an official who said investigators were examining whether a software update was responsible.

A system under strain

The disruption is the latest sign of strain on the US air traffic control system, which has suffered equipment failures, communications problems and controller shortages while the FAA tries to replace ageing infrastructure. Congress approved $12.5 billion for the overhaul last year, and the FAA and the White House asked lawmakers on Friday for another $30.1 billion, France 24 and Al Jazeera reported.

The last nationwide stop was in January 2023, when a key FAA computer system failed and domestic departures were paused for less than two hours. Before that, the only one had followed the 11 September 2001 attacks.