FAA Ground Stop Traced to 1980s-Era Routers, $50B Fix Requested

A nationwide ground stop halted US departures for more than four hours on Friday, and Transportation Secretary Sean Duffy traced the failure to switches and routers in the FAA's telecom network that date to the 1980s. No official root cause has been published. Within hours, the administration had raised its funding request to Congress from $30.1 billion to $50 billion.

The plumbing failed, not the planes. Duffy said at a White House briefing that the US has "old switches, old routers" that became overloaded with data and began producing inconsistent information, at which point the agency shut the system down. He described the result as an "incredibly old air traffic control system" running on "analog telecom."

"How many times does this have to happen before Congress gives the money to fix it?" Duffy said.

What failed, and what did not?

The failure disrupted communications at the air route traffic control centers that handle high-altitude, en route traffic. The FAA runs 21 of these Centers in the continental US plus four combined facilities; in fiscal 2023 they handled 42.3 million en route operations. Each Center's airspace is divided into sectors with their own radio frequencies, remote transmitter sites, and secure landlines to neighboring facilities. All of it rides on the FAA's telecommunications backbone.

That backbone has run under the FAA Telecommunications Infrastructure contract, which Harris Corp., now L3Harris, won in 2002. It relies largely on time division multiplexing over copper wires, a method commercial carriers are phasing out. In 2023 the FAA picked Verizon for a $2.4 billion contract to move the network to Internet Protocol by 2027.

CBS News, citing multiple sources, reported that the outage followed an update to the private communications network that links the system; the network rebooted and then crashed. L3Harris operates that network, according to the report, and has not commented publicly. Homeland Security Secretary Markwayne Mullin said patches and new equipment "was overwhelming the older system." The FBI, Bloomberg reported, does not believe a cyberattack was involved and is examining a software update.

Officials ruled out two popular theories. Mullin said the week's Microsoft 365 outage was not to blame, and Microsoft said it saw no link. Air Space Intelligence, whose SMART tool the FAA recently deployed, said the ground stop "is not based on or a result of the SMART system." The investigation, which involves the NSA, the Defense Department and CISA, has not ruled out an attack.

How bad is the pattern?

Friday was the third nationwide ground stop in US history, after 9/11 and the January 11, 2023 NOTAM database failure, which the FAA traced to contract personnel who "unintentionally deleted files."

The failures since then form a pattern:

• Apr 28 and May 9, 2025: controllers at the Philadelphia TRACON lost radar and radio contact with Newark traffic for roughly 90 seconds each time; Newark's radar data is processed on Long Island and sent to Philadelphia over copper lines.
• Aug 6: an equipment failure at the Minneapolis Center knocked out radar and voice communications for about two hours across a nine-state region.
• September: a circuit failure at a Philadelphia facility and a construction crew's accidental cut of a backup fiber cable in New Jersey delayed or canceled thousands of Northeast flights.

A 2024 GAO assessment rated 51 of the FAA's 138 air traffic control systems unsustainable and 54 more potentially unsustainable.

What would the $50 billion buy?

Congress approved $12.5 billion over five years in July 2025 through the One Big Beautiful Bill Act, which the Transportation Department called a down payment toward roughly $31.5 billion. Congress separately approved $1.9 billion to replace outdated en route centers, according to Reuters.

The $30.1 billion request that Duffy and budget director Russell Vought sent lawmakers included:

• $10.1 billion for air traffic control modernization, of which $7.2 billion for a common automation platform and controller workstations and $2 billion for cloud computing;
• $2 billion to replace and improve towers;
• $18 billion for airport projects, including $10 billion for aging terminals.

The $50 billion figure, raised late Friday, came without a new breakdown. Mullin argued for a single build: "We need one complete system. We need someone to come in and build the whole system. Doing it, nickel-and-diming it together, does not work."

In December 2025 the department named Peraton prime integrator for the new system, with pay tied to performance, and priorities that include moving remaining copper lines to fiber and building a new digital command center. The target is fielding by the end of 2028. The FAA says 68% of its legacy copper network is now fiber.

Timing matters. The administration wants the Republican-led Congress to approve the money before Democrats take control in January, and American, Delta, United and Southwest have backed the earlier request. The FAA has not said when it will publish a root-cause report, so the $50 billion debate will proceed on the strength of a pattern, not a diagnosis.