Federal investigators are examining whether a software update triggered the system failure that grounded all departing flights across the United States on Friday.
The Federal Aviation Administration halted takeops nationwide after a fault disrupted data links at its control centres.
The operational halt affected all 22 centres responsible for guiding aircraft between airports, according to Al Jazeera. The disruption lasted more than four hours, the first nationwide ground stop since a computer system failure in January 2023.
Thousands of flights faced delays or cancellations following the outage. Knock-on disruptions across the aviation network are expected to persist throughout the weekend, while federal authorities work to determine the exact sequence of technical events.
Multiple sources informed CBS News that an update applied to the private network connecting the air traffic control infrastructure caused the system to restart and subsequently crash. Officials have not yet issued an official root-cause analysis.
Transportation Secretary Sean Duffy pointed to ageing infrastructure during a press event on Friday evening, telling Axios that legacy systems had been overwhelmed by a flood of data before failing. Homeland Security Secretary Markwayne Mullin added that officials were actively investigating whether older hardware and newer software failed to interoperate correctly.
Mullin confirmed that officials found no indication of a cyberattack or malicious criminal activity behind the incident. He also clarified that the air traffic control disruption had no connection to a separate global Microsoft outage that occurred on the same day, as reported by CBS News.
The FAA has been actively replacing large portions of its legacy air traffic management technology. The agency integrated an artificial intelligence congestion-management tool around the Washington area in September, though no reporting has linked that specific deployment to Friday’s system failure.
Bloomberg reported that the FBI is reviewing the software update logs to establish how the private network fault propagated across all 22 regional centres. Officials say the investigation continues as flight schedules slowly recover from the four-hour halt.
