Flight operations resumed across the US north-east on Monday evening following a critical infrastructure failure that disrupted service at some of the nation's busiest airports. A primary communications line at a Federal Aviation Administration facility in Philadelphia failed, and when the system attempted to switch to its backup, workers discovered that a fiber-optic cable had been cut by a construction crew, resulting in hundreds of flight cancellations and thousands of delays at Newark, LaGuardia, John F. Kennedy, Philadelphia and Boston airports.
According to reporting from a major news agency, FAA Administrator Bryan Bedford confirmed that the Philadelphia Terminal Radar Approach Control facility lost its primary communications circuit. The backup fiber-optic line, which delivers internet service, was inadvertently severed somewhere between New Brunswick and Newark, New Jersey, by a railroad construction crew. Bedford estimated the fiber break would require approximately 13 hours to repair, with crews simultaneously working to install a replacement circuit.
Transportation Secretary Sean Duffy announced in a Monday evening statement that backup lines had been restored and affected airports were resuming operations.
It will take some time to clear all existing delays, so please check with your airline for the latest information,Duffy wrote. According to reports on the incident, Duffy later indicated that LaGuardia and Philadelphia had resumed flights, while Newark, JFK and Teterboro remained paused at that time.
The incident marked another disruption at the same Philadelphia-area facility that had caused repeated problems at Newark Liberty International Airport in spring 2025. Regional air traffic control centers maintain two separate communications lines—a primary and a backup—to carry radar and communications data. On Monday morning, a circuit on the primary line failed. When the system automatically attempted to switch to the backup, operators discovered that the fiber-optic cable had been severed.
Responsibility for the cable damage remained disputed. Earlier in the day, Duffy attributed the cut to an Amtrak construction crew. However, Amtrak subsequently pointed to a New Jersey Transit construction crew that was working in the area between Newark and New Brunswick.
What does this reveal about aviation security?
The disruption coincided with the release of a Government Accountability Office report that exposed significant vulnerabilities in the FAA's approach to protecting aircraft communications from cyberattacks. The watchdog found that the FAA has yet to complete risk assessments or update security documentation covering threats from spoofing, jamming and other attacks on the radio spectrum. According to reporting on the security assessment, the FAA also lacks a real-time system to detect all such threats, meaning it can generally only investigate incidents after they are reported.
The report warned that a hacker could send fraudulent messages—such as false cancellations of flight clearances—to aircraft, with the potential to cause delays, disrupt airspace or create safety risks. Two systems used to send text messages to aircraft predate modern cybersecurity standards and lack common protections such as encryption.
Senator Ron Wyden of Oregon, who sits on the Senate intelligence committee, issued a stark warning in response to the findings.
The FAA's failure to require the aviation industry to use secure communications is a major threat to US national security, to our economy and the safety of the flying public,Wyden said.
This sobering report reveals that the technology used by air traffic controllers to communicate with aircraft is incredibly insecure, can be intercepted, impersonated, and jammed, and that hackers and foreign governments can exploit these vulnerabilities to disrupt air travel and even put passengers at risk.
Wyden called for immediate action, stating:
The FAA needs to issue new standards, as soon as possible, to protect the security of airline communications.
What recommendations did the watchdog make?
The GAO issued nine recommendations to address the security gaps, including conducting formal risk assessments of seven of eight reviewed systems, implementing continuous monitoring for interference, spoofing and jamming, and establishing formal guidance on information sharing between agencies. The Department of Transportation, responding on behalf of the FAA, agreed with all nine recommendations.
How does this fit into a broader pattern?
Monday's disruption represents the latest in a series of problems affecting the Philadelphia facility. In April 2025, a similar failure at the same location lasted roughly 60 to 90 seconds and severed contact between controllers and aircraft, prompting the FAA to halt departures. In response to those earlier incidents, the FAA upgraded the Philadelphia Tracon to a new fiber-optic link with New York on two separate paths as part of measures intended to improve reliability.
The FAA handles more than 44,000 flights daily and serves approximately 3 million passengers, according to the GAO report. The security vulnerabilities identified extend beyond US borders. Estonia and Finland have accused Russia of interfering with satellite navigation in their airspace, allegations Moscow denies. One incident involved a Spanish military jet carrying the country's defense minister.
What happens next?
FAA and airline crews continued repair efforts on Monday evening, with normal operations expected to return only after both the replacement circuit and the damaged backup fiber were fully restored. Passengers at affected airports were advised to contact their airlines for updated flight schedules, as clearing existing delays was expected to take additional time beyond the initial restoration of communications systems.
Key Facts
- A primary communications line failed at the Philadelphia Terminal Radar Approach Control facility on Monday morning, with a backup fiber-optic cable discovered to have been severed by a construction crew
- Hundreds of flights were canceled and thousands delayed at Newark, LaGuardia, JFK, Philadelphia and Boston airports before service resumed Monday evening
- A Government Accountability Office report released the same day found the FAA lacks adequate cybersecurity measures for aircraft communications systems, including real-time threat detection
- The same Philadelphia facility had caused disruptions at Newark Liberty International Airport in spring 2025, prompting previous upgrades to backup systems
- The FAA handles over 44,000 flights daily and serves approximately 3 million passengers
