AI tool did not cause 4-hour US flight halt

The US Federal Aviation Administration stopped departures at all US airports for more than four hours on the 13th of November 2026. Officials said a new AI tool did not cause it.

The FAA blamed communication problems at its air traffic control centers. More than 3,500 planes were in the air when it began, Transportation Secretary Sean Duffy said.

Old routers overloaded

Old switches and routers got overloaded with data and gave wrong readings, Duffy said, GeekWire reported. Newer equipment held up, he said.

Airspace reopened at about 03:15 Athens time on the 14th of November, GeekWire reported. Some flights may not leave until Saturday morning, Duffy said.

The AI tool under question

The tool, called SMART, uses AI to suggest flight routes and schedules. The FAA expanded it to all 22 of its route centers three days earlier, The Washington Times reported.

Its maker, Air Space Intelligence, said the stop was not a result of SMART. Duffy said the tool is not even plugged into the core systems.

Homeland Security Secretary Markwayne Mullin said there was zero evidence of a cyberattack so far. Microsoft said it saw no link to its own outage.

Below we break down the cost

FlightAware counted nearly 7,000 flights delayed or canceled by Friday afternoon, GeekWire reported. The SMART deal is a 12 year contract worth 875 million dollars.

That is about 73 million dollars a year, by our arithmetic.

What is confirmed and what is not

The FAA called its first statement preliminary. Mullin said nothing is completely certain yet, but the cause appears mechanical.

Key facts

The FAA halted all US departures on the 13th of November 2026.

The stop lasted more than four hours.

Officials blamed old, overloaded telecom equipment.

The maker of the SMART AI tool said it was not the cause.