US Aviation System Failure Grounds Flights Nationwide, Disrupting Thousands of Departures

More than 11,000 departing flights were canceled at airports across the United States overnight Friday into Saturday following a widespread communications failure that disrupted air traffic control systems nationwide. More than 4,000 aircraft were reportedly en route to the US when the emergency was declared, forcing hundreds of flights to return to their departure airports or divert to other countries.

The disruption began shortly before midnight Friday, Israel time, when the US air traffic control center reported instability in radar and communications systems. In response, the Federal Aviation Administration (FAA) ordered a nationwide ground stop, suspending both domestic and international departures. Aircraft already airborne were permitted to land.

The shutdown lasted more than four hours. According to US Transportation Secretary Sean Duffy, American airspace reopened at 8:15 p.m. New York time, corresponding to 3:15 a.m. in Israel.

Aging Communications Systems Blamed for Widespread Disruption

Duffy attributed the failure to outdated switches and routers that became overwhelmed by data from a newly introduced system. The aging equipment began transmitting inconsistent information, prompting officials to shut down the system as a precaution. He emphasized that radar and communications data were never completely lost.

Homeland Security Secretary Markwayne Mullin told CNN that the FAA had integrated new technology into an existing infrastructure, overwhelming the older system. An aviation industry source told the network that the malfunction simultaneously affected radar systems and radio frequencies used to communicate with pilots across multiple regions, leaving even air traffic controllers initially uncertain about what was happening.

Two airline industry sources told Reuters that the disruption appeared to be connected to a communications network overseen by L3Harris, which manages radio frequencies used by air traffic controllers. The company did not respond to requests for comment.

Officials Say No Evidence of Cyberattack

US officials maintained that there was no evidence of a cyberattack, despite reports that the national meteorological service's systems also experienced outages during the disruption.

Mullin told CNN that investigators had found no evidence pointing to a cyberattack, although the possibility had not been definitively ruled out. The National Security Agency (NSA) is reportedly participating in the investigation alongside the Department of Homeland Security.

The incident was described as only the third nationwide aviation shutdown in US history. The first occurred following the September 11 terrorist attacks in 2001, while the second took place in January 2023, when a malfunction in the Notice to Air Missions (NOTAM) system briefly halted departures across the country for less than two hours.