Investigators are examining whether a software update contributed to the nationwide air traffic disruption on Friday, November 13, according to a Bloomberg report citing a person familiar with the matter. That possibility directs attention toward the change controls described by L3Harris, the contractor operating the Federal Aviation Administration’s communications network.
CBS separately reported an update-and-reboot account from unnamed sources. The published accounts reviewed for this article identify no software version, rollout time or author of the code. Identifying the network’s operator does not establish who made, installed or approved a particular update.
Transportation Secretary Sean Duffy blamed overloaded old equipment and said newer switches stayed up. SMART, the FAA’s planning tool, is not connected to those control systems, he said. Homeland Security Secretary Markwayne Mullin linked patching and new technology to overwhelmed older hardware.
L3Harris has described a deliberate process for changing that infrastructure. In a May 11, 2026 update, the company said it installs replacement equipment alongside systems already operating, tests the two in parallel, then switches service during coordinated periods with little traffic and with backups available. At that date, it said it was installing 150 to 200 paths a month and had passed 50 percent completion.
Those published procedures identify several distinct protections: keep the existing service running during installation, test its replacement before switching, choose a low-traffic period and retain another way to carry communications. They describe the company’s modernization approach. L3Harris has not supplied, in the material reviewed here, the maintenance record showing which of those steps applied to the reported November 13 change.
Its separate FAA Telecommunications Infrastructure capability page describes multiple carriers, built-in redundancy, maintenance windows and parallel systems. The company says the network carries voice, radar, weather and other air traffic information. A disruption to shared communications can therefore affect more than the voice channel a passenger might imagine when hearing that controllers lost contact.
That capability page also claims 99.99971 percent network reliability, without defining the measurement period or which services enter the calculation. It supplies too little detail to compare that figure reliably with hours of departure restrictions. Network availability, the functioning of individual links and an agency’s decision to stop takeoffs are different measures.
The FAA has previously faulted backup oversight. On September 20, 2025, it blamed an earlier Dallas outage on Frontier telecommunications failures and said L3Harris oversight failed to ensure redundancies worked. That finding concerns a different incident, more than a year before Friday’s halt.
A November 2023 safety review commissioned by the FAA had also warned about obsolete telecommunications and risks during replacement. It described the possibility that a facility or an entire control center could lose connectivity during the transition. That was an advance warning about the network’s vulnerability, rather than an investigation of this week’s failure.
The FAA’s national stop ended Friday evening. Its cancellation advisory was issued at 8:19 p.m. Eastern, after Duffy’s reported 8:15 p.m. reopening. The unresolved software question now requires a sequence: which change preceded the disruption, which equipment and paths it reached, and how backup arrangements responded. No public technical account obtained for this article supplies that sequence.
