11,000 Flights Disrupted as FAA Lifts Nationwide Ground Stop

More than 11,000 flights across the United States were delayed or canceled Friday after the Federal Aviation Administration issued a rare nationwide ground stop, an order the agency lifted roughly four hours later once officials said they had identified the cause, according to The Guardian, citing figures from aviation tracker FlightAware.

At Los Angeles International Airport, passengers watched ground crews unload luggage from an idled United plane, one of the scenes that played out at airports nationwide as the order rippled through the system, the Guardian reported. The FAA confirmed on its website that the airspace had reopened.

What triggered the FAA's ground stop?

Transportation Secretary Sean Duffy said the trouble began at 3:36 p.m. Friday, when air traffic control centers experienced instability in radar and communications systems. "What we have is an incredibly old air traffic control system," Duffy said at a White House briefing Friday evening, according to the Guardian. "Our routers actually got overloaded with data, and ... they started to give us inconsistency in the data from those routers. And because of that, we shut the system down." An FAA notice cited to the Guardian said the stop was imposed "due to extraordinary circumstances and for reasons of safety."

How many flights and planes were affected?

FlightAware data cited by the Guardian showed more than 11,000 US flights were delayed or canceled. Duffy said more than 3,500 airplanes were in the air when the stop was ordered, according to the Guardian's account of the briefing.

When did the FAA lift the order, and is travel back to normal?

Duffy said the airspace reopened at 8:15 p.m. Eastern time. "So at 8.15 tonight, Eastern Time, we've opened up the airspace," he said, according to the Guardian. "But it's going to take us some time to unwind what's happened this afternoon." He said the government had "identified the problem" and that the system "is operational right now," though he did not give a timetable for when flight schedules would fully normalize.

Why is the administration pressing Congress on funding?

The briefing, which also included Homeland Security Secretary Markwayne Mullin, turned into what the Guardian described as a plea for funding from Congress to "fully fund a full build of a brand new air traffic control system." Duffy's characterization of the infrastructure as outdated, paired with the router overload he described, formed the basis of that appeal, though the Guardian's report did not include a specific dollar figure or timeline attached to the request.

What do officials still not know?

The Guardian's reporting left open exactly how long full recovery will take and what specific fix, beyond identifying the overloaded routers, resolved the instability. Duffy's comments establish that the system is running again, but his own caution that "it's going to take us some time to unwind" the day's disruptions suggests delays and cancellations tied to Friday's stop could continue to work through the schedule in the following days.

The FAA's advisory and Duffy's remarks at the briefing remain the primary record of what happened and when, according to the Guardian's account.