Microsoft outage and US flight disruptions: Is there a link?

Microsoft has denied any link between its own global outage and the air traffic control failure that grounded every departing flight in the US on Friday. More than 10,000 flights were delayed and over 6,600 cancelled, according to flight tracker FlightAware.

“We have no indication that the FAA’s nationwide ground stop is related to any Microsoft services,” the company wrote on X, hours after the Federal Aviation Administration (FAA) froze takeoffs nationwide. The suspicion was easy to understand. Microsoft 365 had been down since Thursday, knocking out Outlook, Teams, Copilot and even Xbox Live for users in 74 countries. Then, just before 4pm ET on Friday, the FAA’s 22 regional air traffic control centres started losing radar data and radio contact with aircraft. Two massive tech failures in two days was enough for people online to connect them. Homeland Security Secretary Markwayne Mullin did not buy it. He told reporters they were “separate issues” and that he did not see “any reason to connect those two at all.”

An old FAA network, not Microsoft or AI, caused the US flight ground stop

Transportation Secretary Sean Duffy put the blame on the FAA’s ageing network. “Our switches, our routers actually got overloaded with data,” he said at a White House briefing, describing a system that still runs on “1980s little copper lines.” The trouble started at 3:36pm ET, and the ground stop was lifted at 8:15pm ET. Data firm Cirium estimates around 1.5 million people were stranded. Mullin said there was “zero evidence” of a cyberattack. Asked if AI was involved, he replied, “we call it SI around here,” using the administration’s preferred term for artificial intelligence. AI was an obvious suspect. Three days earlier, the FAA had switched on SMART, an AI-powered traffic planning tool from Air Space Intelligence, at all 22 centres. The company posted on X that the ground stop “is not based on or a result of the SMART system.” Duffy was blunter. “This is not even plugged in,” he said.

Microsoft and FAA outages both trace back to network changes

The two failures are unrelated, but they started in similar places. Microsoft has said it is “deeply sorry” for its outage and called it “a technical issue not related to cyber or AI / agents.” The company traced it to a flaw from an earlier network capacity upgrade that surfaced after a more recent network change.

Think tank Anderson Economic Group estimates the lost productivity could cost close to $7 billion. At the FAA, reports citing people briefed on the matter say an update to the agency’s private telecom network, run by defence contractor L3Harris, made it reboot and then crash. Mullin’s account fits that picture. He said new equipment patched into the system “was overwhelming the older system.” Duffy now wants $50 billion in emergency funding from Congress to rebuild air traffic control, up from the $30 billion the administration had been seeking. “It’s going to continue to fail,” he warned. Microsoft is off the hook. The network that failed on Friday, built on copper lines older than Outlook itself, is the one carrying US flights again.