Transportation Secretary Sean Duffy explains what caused FAA nationwide ground stop: Contractor error or faulty equipment

Transportation Secretary Sean Duffy on Saturday suggested that an FAA contractor might be to blame for Friday’s telecommunications outage, as per his remarks at a press briefing at Transportation Department headquarters. The outage grounded flights across the country and led to thousands of cancellations.

Sean Duffy says contractor error or a faulty router may have caused Friday's nationwide FAA ground stop. (Bloomberg)
Sean Duffy says contractor error or a faulty router may have caused Friday’s nationwide FAA ground stop. (Bloomberg)

According to Duffy, “in at least one of our remote FAA locations, a contractor was doing routine maintenance to switch telecommunication lines from old copper wire, and they were bringing it over to fiber.”

L3Harris named, but fault not yet found

Duffy named the contractor as L3Harris. “That contractor that does the work for us is L3Harris. They’re our legacy provider,” he said. He added that officials are still trying to figure out what went wrong.

“Was it user error or installation error from L3Harris, or did they install a faulty router? We haven’t determined what the fault was,” Duffy said, as per Huff Post.

Also read: US flights grounded nationwide: A look back at the last major FAA shutdown in 2023

How a router caused the ground stop

Duffy explained what caused the FAA Nationwide Ground Stop on Friday. “Either through contractor error or a faulty piece of equipment, that router that was being replaced as we switched from copper to fiber, it started flooding other routers in our air traffic control system. So specifically, we had over 1,000 connection attempts every four to five seconds. And what that did was give us issues with communication with airplanes, and it also caused some disruption with radar feeds.”

He said the airspace was shut down for safety. “When we see that, your safety is paramount. We shut down the airspace and we do it safely. We get you on the ground and then we work on isolating the problem and then opening the airspace back up, which is what we did yesterday.”

Also read: FAA employee explains possible cause of nationwide ground stop on flights: ‘Wouldn’t rule out cyberattack’

No cyberattack, says Duffy

Duffy also dismissed speculation that the outage was a cyberattack. “Once we were able to isolate the work that was being done at this remote location, all of our systems came back online,” he said. “So we don’t believe this was cyber at all.”

He added, “This was an FAA system that didn’t meet the moment. A contractor didn’t meet the moment, or the equipment didn’t meet the moment and caused the outages.”

What happened on Friday

The FAA ordered a nationwide ground stop at 3:54pm Eastern Time on Friday, as per Al Jazeera. This meant planes waiting to take off had to stay on the ground. The reason was a telecommunications outage that hit air route traffic control centres, which manage flights across the country. Planes already in the air were allowed to continue and land. International flights were handled case by case, and some were allowed to leave.

Duffy said airspace opened again at 8:15pm ET, after more than four hours. “We’ve opened up the airspace,” he said, but warned that flights would not restart right away. “It’s going to be slow,” he added.

According to Al Jazeera, this was the country’s longest ground stop in 25 years. It was also only the second nationwide ground stop of all departures since the September 11, 2001, attacks. Homeland Security Secretary Markwayne Mullin said, “Everybody’s safe.” He added that this was not “another 9/11” and that no cyberattacks were suspected.

As per FlightRadar24, more than 4,700 flights were cancelled and 10,000 were delayed on Friday. Another 700 flights were already cancelled for Saturday. According to Cirium, at least 827 flights were diverted by 7:05pm ET. Of these, 670 went back to the airports they left from, and 157 landed at other airports.