Equipment upgrade glitch at remote site grounds US flights for over four hours

A major disruption in the US air traffic control communication system forced a ground stop lasting more than four hours. The problem began when outdated equipment at a remote site was being upgraded, and this coincided with a surge in connection attempts. The combination led to intermittent communication and radar failures. Several regional control centers across the country were affected as a result. The incident caused widespread flight groundings during the outage.