Transportation Secretary Sean Duffy wants $50 billion in emergency funding after outdated telecommunications equipment triggered a nationwide ground stop that halted U.S. air traffic for nearly five hours on Friday.

The Federal Aviation Administration stopped all departures at 3:36 p.m. after radar and communications systems became unstable at air traffic control centers across the country. More than 3,500 aircraft were airborne when the disruption began, according to Duffy, who said controllers safely guided those planes to land while keeping emergency medical and law enforcement flights moving.

The FAA reopened U.S. airspace at 8:15 p.m. Duffy warned that disruptions would persist as airlines repositioned aircraft and crews. The halt also spilled into ground transportation: travelers hunting for alternatives reported problems accessing Amtrak's booking website as demand for train tickets surged.

What caused the outage?

Duffy said Friday evening that aging switches and routers became overloaded with data, producing inconsistencies in radar communications systems nationwide. Newly installed equipment kept functioning, he said, while older technologies failed.

"We were able to deploy fixes to reduce the overloading on our switches," Duffy said. The repairs, he added, suggested the failure involved older equipment rather than newly deployed systems.

Homeland Security Secretary Markwayne Mullin said investigators had found no evidence of a cyberattack but had not completely ruled out malicious activity. Officials have not established whether aging infrastructure, recent upgrades, or another problem caused the disruption.

Did the new SMART system play a role?

The FAA this week expanded its artificial intelligence-assisted SMART platform — Strategic Management of Airspace, Routes, and Trajectories — to all 22 air traffic control centers, following its initial deployment in the Washington, D.C., area in September. The system combines weather conditions, flight data, and traffic patterns to help controllers identify more efficient routes.

Rep. Jesus Garcia (D-IL), a member of the House aviation subcommittee, raised the possibility Friday that the rollout was connected to the disruption, according to NBC News. Aviation officials have not confirmed any link, and the system's developer, Air Space Intelligence, denied that its technology caused the outage.

Duffy's account pointed the other way: the fixes deployed to the overloaded switches indicated the failure sat in legacy equipment, not the SMART systems.

Why the aging centers matter

The disruption focused attention on Air Route Traffic Control Centers, the FAA facilities that direct aircraft through large sections of U.S. airspace between takeoff and landing. The country has 22 such centers, which rely on telecommunications networks and radio frequencies to communicate with pilots and coordinate movements.

These facilities rank among the oldest components of U.S. air traffic infrastructure. Sen. Ted Cruz (R-TX), chairman of the Senate commerce committee, noted Friday that no new ARTCC has been built since President Lyndon B. Johnson held office — a span of more than five decades.

Cruz called the nationwide ground stop a rare but significant disruption and said it highlighted the need to prioritize modernizing the centers over other projects. Sen. Maria Cantwell (D-WA), the commerce committee's top Democrat, said lawmakers would examine the failures involving primary and backup communications frequencies.

The FAA has spent years replacing outdated communications equipment, such as copper wiring and analog systems, with modern digital technology. Duffy said Friday that aging analog telecommunications equipment, including decades-old copper lines, contributed to the disruption.

How much is on the table?

Congress allocated $12.5 billion in July 2025 to begin overhauling the air traffic control system, funding the replacement of radar software, telecommunications equipment, and other infrastructure across more than 10,000 projects. According to the government's Modern Skies project tracker, workers have replaced more than 60% of the nation's legacy copper telecommunications lines with fiber-optic and wireless infrastructure since then.

Duffy and FAA Administrator Bryan Bedford have been pressing Congress to approve the Modern Skies Act, which would add $30 billion to finish the job. The proposal splits the money three ways:

• $10 billion for replacing aging control towers and ground facilities
• $10 billion for telecommunications upgrades and converting analog equipment to digital systems
• $10 billion for additional infrastructure and software improvements

On Friday evening, Duffy escalated that request. He said he now wants $50 billion in emergency funding to complete a comprehensive overhaul rather than continue piecemeal repairs.

"This is an emergency," Duffy said. "I want Congress to give us emergency funding."

What comes next for operators?

Duffy warned that aging infrastructure would keep failing without full replacement. He also said he expects flight operations to recover before the Thanksgiving travel rush, giving airlines a narrow window to reset schedules and reposition crews. For carriers and airport operators, the outage is the clearest signal yet that Washington's modernization timeline, not just its funding level, will shape operational risk through the busy holiday season.