Cause of the malfunction that halted flights in the US: aging air traffic control equipment

The US Federal Aviation Administration (FAA) announced that the malfunction that halted all departures across the country was caused by a glitch that occurred during the replacement of aging air traffic control equipment. The crisis began on Friday afternoon when the FAA halted all departures shortly before 16:00 local time, citing extraordinary conditions and safety concerns. More than 3,500 aircraft were in the air when the decision was made.

Airlines canceled 8,600 flights on Friday and removed roughly 2,500 more flights scheduled for Saturday from their programs. According to aviation data company Cirium, more than 30 percent of flights departing from the US on Friday were canceled. After airports became gridlocked due to the density of aircraft on the ground and insufficient parking space, hundreds of flights were forced to turn back or be diverted to other airports.

Transportation Secretary Sean Duffy said at a press conference at the White House that "telecom routers subjected to excessive data loads" broke down and created a nationwide crisis. "What we have is an incredibly old air traffic control system," Duffy said, calling on Congress to approve funding for system upgrades estimated to cost 50 billion dollars.

President Donald Trump said the nationwide ground stop did not appear to have stemmed from a cyberattack or from artificial intelligence. Homeland Security Secretary Markwayne Mullin also stated that so far there is no indication that the outage was caused by a cyberattack, saying "There is no reason for the public to be afraid."

According to government and industry officials, the outage appears to be linked to the telecommunications network overseen by L3Harris Technologies that manages the critical radio frequencies air traffic controllers use to talk to pilots. Stating that outages will recur if a comprehensive overhaul of the air traffic system is not carried out, Duffy recalled that similar situations were seen in the Northeast region in September and around Newark Liberty International Airport last year: "You are going to see more of these."

United Airlines reported that it will work to get passengers to their destinations once the problem is resolved, while American Airlines said in a statement, "All teams across American Airlines will be mobilized to get our customers on their way as soon as possible." Many airlines granted waivers allowing passengers to rebook without paying a penalty.