FAA Lifts Nationwide Ground Stop After Legacy Telecom Fault Halts Flights
The FAA lifted a nationwide ground stop at 8:15 p.m. Eastern on November 13, 2026, ending a halt to flights that had begun that afternoon. According to Engadget, hundreds of flights were canceled, thousands of aircraft already airborne were diverted, and millions of passengers were stranded during the stop.
US Transportation Secretary Sean Duffy attributed the stop to the age of the country's air traffic control infrastructure. He said US air traffic facilities still rely on TDM (time-division multiplexing) telecom, which he described as a legacy analog telecommunications technology, to move information between facilities. The TDM routers became overloaded with data, and by 3:36 p.m. Eastern on November 13 they had begun transmitting inconsistent information. The FAA then grounded flights as a precaution.
Duffy said the failure was confined to the older equipment. Air traffic systems that had already been replaced were not affected. He also said the country did not lose all communications and radar capability, and that the grounding was ordered out of an abundance of caution.
The distinction matters for operators. A partial failure that corrupts data across shared transport is harder to contain than a clean outage, because controllers cannot be certain which position feeds are trustworthy. That uncertainty, more than a total loss of signal, appears to have driven the decision to halt traffic.
Homeland Security Secretary Markwayne Mullin said there was no indication the communications problems were caused by a cyberattack. He also said the FAA incident was not related to a Microsoft services outage that lasted more than 24 hours.
The funding picture is a central thread. Congress has provided the FAA with $12.5 billion to modernize US air traffic facilities, according to the same report. Duffy has sought an additional $30 billion. The request is pending.
In my view, the most useful way to read the November 13 event is as a test of the boundary between replaced and unreplaced infrastructure. The fact that upgraded equipment held while the legacy links failed is the strongest evidence available about where the risk sits. The open question is how quickly the remaining TDM-based links can be retired, and whether the $30 billion request, if funded, would extend the replacement to every facility that still depends on them.
The broader context here is that air traffic control has long run on a mix of technology generations, with newer systems layered onto older transport. Each interface between the two is a point where a fault can spread. Replacing the legacy segments would not remove the need for careful failover design, but it would reduce the number of places where inconsistent data can enter the network. For the engineers who will carry that work out, the immediate lesson is that a grounding this broad followed a degradation in data integrity, not a loss of service, and the modernization effort will be judged on how it addresses that distinction.
