Transportation secretary says routine equipment upgrade caused nationwide flight groundings

Transportation Secretary Sean Duffy told reporters on Saturday that a nationwide ground stop, which halted flights across the United States, stemmed from a seemingly routine equipment upgrade.

The upgrade involved replacing copper wire at a remote site with fibre‑optic cable by L3Harris, a long‑standing contractor for the FAA, after which a router overloaded a critical communications system, prompting the stop. “It’s pretty straightforward work that we were doing yesterday at, again, a very remote location,” Duffy said at a Saturday press conference that suffered technical glitches of its own. “What we’re working to determine was whether we had incompetence — meaning, was it user error or installator error from L3Harris? Or did they install a faulty router?”

FAA acting chief technology officer Rebecca Guy explained that the network began showing instability, leading analysts to identify two sources pinging the network at a very high rate — “a thousand connections over every four to five seconds.” She added the agency disabled “both of those, right away and were able to stabilize our network,” and is now conducting a root‑cause analysis.

Duffy has repeatedly urged Congress to fund more aviation equipment upgrades and, when asked why the switch‑over occurred at 3 p.m. on a Friday rather than overnight, said larger airports are handled at night while remote sites are serviced during the day. “There will be reevaluation of when we do this work,” he said.

The incident marked only the third nationwide ground stop of the 21st century, with more than 8,200 flights cancelled on Friday evening and at least another 3,000 on Saturday, according to data firm Cirium. The stop came a day after the FAA announced an AI tool for air‑traffic controllers, which the controllers’ union said it had not helped design. FAA administrator Bryan Bedford said there was “zero evidence of anything nefarious and zero evidence of anything AI‑related.” He added, “We want to be clear that we have an equipment issue, and we’re working through what this defective piece of equipment was,”.

Homeland Security Secretary Markwayne Mullin, when asked if AI was involved, replied, “We call it SI around here, remember? SI.”