Note, 14 November 2026

How an old network stopped every US airport

At 3:54 pm Eastern on Friday 13 November 2026 the FAA ordered every US airport to hold departures. They resumed at about 8:15 pm. The Transportation Secretary blamed overloaded routers on an old network. The FAA itself has named no cause. This is that account, drawn, with what is and is not known.

What happened

All times are US Eastern, on Friday 13 November 2026.

At 3:54 pm the FAA Command Center signed Advisory 111: "ALL AIRPORTS ARE GROUND STOPPED. ALL DEPARTING TRAFFIC SHOULD REMAIN GROUND STOPPED UNTIL FURTHER NOTICE." (FAA Advisory 111)

The Transportation Secretary said departures opened up again at 8:15 pm at the evening briefing (US DOT). The FAA's cancelling Advisory 005 is signed at 8:19 pm (FAA Advisory 005). Either way, more than four hours.

The FAA's own statement says the stop followed "communication issues impacting multiple Air Route Traffic Control Centers" and that technicians were investigating (FAA). It names no cause.

The Secretary's account

The Transportation Secretary said that at 3:36 pm "we experienced instability for our radar and our communications and our centers and our TRACONs across the country."

Asked what caused it, the Secretary said: "We have old switches, old routers. We use 1980s little copper lines. It's an old system that went down and went down everywhere, it got overloaded." (briefing transcript)

That is a preliminary assessment, not a finished investigation. The Homeland Security Secretary described it differently: new equipment that was overwhelming the older system (CNN). Reporting by CBS, from unnamed sources, pointed to an update to the network. We cannot tell which is right, and the copper lines are the Secretary's description of the network, not a part anyone says failed.

How a flight is handed on

In the Secretary's words: "at airports we have towers. The next rung out is a TRACON. After that, we have En Route Centers."

A TRACON is the approach control that guides aircraft in and out of a city's airspace. The en route centers take over from there and cover the country between cities. A flight is passed along that chain, and each hand-off depends on the data and the radio links between the sites.

"Inconsistent data" is the Secretary's phrase for what the TRACONs and centers began to see: the Secretary said "inconsistency in the data from the radars and our communication with airplanes". The Secretary also said not all telecom and not all radar was lost. Some of it still worked, and in a system that guides aircraft, an input that sometimes disagrees may be reason enough to stop.

Aircraft in the air, and the copper count

When the stop began, the Secretary said, more than 3,500 aircraft were in the air. Officials said all of them were accounted for.

The copper figure comes from the Government Accountability Office, which reports FAA numbers. As of May 2026 the FAA had replaced 2,560 of 5,170 copper lines with fiber, leaving 2,610 (GAO-26-107992). That is about half.

Two cautions. GAO dates that copper to the 1960s; "1980s" is the Secretary's phrase. And GAO's report does not mention the 13 November outage, so it does not say copper caused it. The figure is from May, not from the day.

What the film shows

An airliner rolls up to a runway hold line and stops as a row of red lights comes on. Behind it, more airliners queue. In the sky, a link passes the flight from tower to approach control to two centers, then flickers and goes out. At night the airliner is still waiting.

It is an illustration. There is no real airport, airline or flight in it, and no footage. It follows the Secretary's account as the Secretary gave it. The voice is synthetic.

Our earlier film on the same afternoon is drawn from real aircraft positions: the same afternoon in flight data.

What we do not know

We do not know the cause. The FAA has published none, and the accounts above differ. We do not know whether the copper lines the GAO counts are the ones the Secretary meant, or whether they played any part. We do not know how many flights were affected beyond the figures in the sources.

One line of the film says the planes were not the problem. We found no report of an aircraft fault. But radio trouble was reported, and hundreds of flights were diverted, so treat that line as our reading, not a finding.

Transcript

On Friday, this airliner was grounded.

Every American airport stopped departures.

The planes were not the problem.

The Transportation Secretary blamed overloaded routers, on what the Secretary called 1980s copper lines.

How does an old network stop a plane?

Each flight is handed from tower, to approach control, to en route centers.

At 3:36, the Secretary said, their radar and radio data turned inconsistent.

So at 3:54, the FAA stopped takeoffs nationwide.

Thousands of planes were already in the air. All were accounted for, officials said.

It lasted more than four hours.

In May, half of the agency's copper lines were still waiting to be replaced.

All notes