Flights halted at three US airports as watchdog warns over hacking threat

A congressional watchdog has warned the systems guiding US aircraft are open to interference and deception as flights into three busy airports in the country’s north east US were halted by a radio equipment problem.The Federal Aviation Administration (FAA) ordered a ground stop at about 10am on Monday for Newark Liberty international, Philadelphia international and Teterboro airports, saying some radio frequencies at the Philadelphia terminal radar approach control (Tracon) were affected until the early afternoon. Arrivals and departures at Newark were delayed, and the agency has not said what caused the outage.The disruption coincided with the publication of a Government Accountability Office (GAO) report, which found that the FAA has yet to finish risk assessments or update security documentation covering threats from spoofing, jamming and other attacks on the radio spectrum – prompting a prominent senator to warn of a “major threat” to National Security.The FAA also lacks a real-time system to detect all such threats, the report said, meaning it can generally only investigate incidents after they are reported.Investigators 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, according to the report.The watchdog’s findings prompted calls for swift action. “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,” said Ron Wyden, the US senator for Oregon, who has long campaigned on privacy, surveillance and cyber security issues.“The FAA needs to issue new standards, as soon as possible, to protect the security of airline communications.”The GAO made nine recommendations, including a formal risk assessment of seven of eight reviewed systems, continuous monitoring for interference, spoofing and jamming, and formal guidance on information sharing. The Department of Transportation, replying for the FAA, agreed with all nine.Monday’s disruption is the latest in a run of problems around Newark. In April 2025, an outage blanked controllers’ screens for roughly 60 to 90 seconds and cut their contact with aircraft, prompting the FAA to halt departures. The FAA later moved the Philadelphia Tracon to a new fiber-optic link with New York on two separate paths, as part of measures to improve reliability.The FAA handles more than 44,000 flights a day and about 3 million passengers, the GAO noted.Wyden, who sits on the Senate intelligence committee, added: “This sobering report from [the] GAO 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.”The GAO also pointed to jamming and spoofing abroad. Estonia and Finland have accused Russia of interfering with satellite navigation in their airspace, which Moscow denies.One incident last September involved a Spanish military jet carrying the country’s defense minister.