Replacing old wiring led to the collapse of aviation in the United States.
The cause of the large-scale failure was an attempt to modernize the flight controllers' communication system. As US Transportation Secretary Sean Duffy said, during the replacement of copper cables with optical fibers, technical problems arose that disrupted the operation of the air traffic control system.
Earlier, the US Federal Aviation Administration temporarily banned flights from all airports in the country. The restrictions resulted in delays and cancellations of thousands of flights. The ban has now been lifted, and air traffic, according to Duffy, has been fully restored.