On May 11, local time, operations at Newark International Airport in the United States returned to normal. Early that morning, the U.S. Federal Aviation Administration grounded flights to Newark International Airport due to air traffic control equipment failure. The ground grounding lasted for about 45 minutes.

The Federal Aviation Administration said in a statement,The system responsible for guiding aircraft in and out of Newark International Airport's airspace suffered a telecommunications glitch., the agency slowed the movement of planes in and out of the airport to ensure redundant systems were operating as designed.
In addition, the U.S. Federal Aviation Administration issued an announcement on the 11th that due to equipment failure, some flights to Hartsfield-Jackson Atlanta International Airport in Georgia were grounded. It's unclear what the specific details of the glitch were and whether it was related to the incident at Newark International Airport.
U.S. Transportation Secretary: Newark International Airport’s air traffic control system is old

△U.S. Secretary of Transportation Sean Duffy (file photo)
On May 11, local time, U.S. Secretary of Transportation Sean Duffy responded to the recent frequent malfunctions at Newark International Airport in an interview with NBC, saying,The air traffic control system used at Newark International Airport is old., may have been used for 25 to 50 years, and the U.S. Congress did not pay attention to this issue in time before.What happened at Newark International Airport could happen elsewhere in the U.S., the U.S. government must fix the system to solve the problem.
Sean Duffy said that the reason for frequent failures was related to telecommunications problems. There were also some failures in related software. The input of information overloaded some lines, causing the entire system to malfunction.