Most flights leaving the United States stopped for about five hours on Friday, 13 November. The Federal Aviation Administration (FAA) made this decision after a communications failure at air traffic control centres. It was the longest time in 25 years that flights across the US were not allowed to depart. More than 4,700 flights were cancelled and about 10,000 were delayed. Problems for passengers continued through the day and into the weekend.

The most important cause was new technology added to the US air traffic control system. This system also uses older equipment. The mix of old and new technology overloaded the system and made it hard for air traffic controllers to talk to pilots and track planes. US officials did not find any evidence of a cyberattack. They are still investigating the problem.

The main result was major disruption at airports across the US. Many people had to wait a long time or change their plans. Airlines and airports spent hours dealing with delayed, cancelled, or diverted flights. The FAA and other officials said they will check the system to try to stop this problem happening again.