Nationwide Radio Frequency Collapse Grounds Flights Across Greece, Stranding Thousands

Greek aviation authorities suspend arrivals and departures nationwide on Sunday after a sudden collapse of the radio frequencies used for air-traffic control, effectively clearing much of national airspace and leaving thousands of travellers stranded. The disruption began in the morning, first noted around 0700 GMT (about 9:00 a.m. local time), when control centres responsible for much of Greece's traffic lost contact channels with aircraft.

State broadcaster ERT and airport statements said operations at major airports, including Athens Eleftherios Venizelos, were halted from about 9:00 a.m. local time. Flight-tracking imagery from FlightRadar24 showed an almost empty sky over Greece at the height of the outage, with some overflights continuing but airport operations heavily restricted for safety. Airport officials reported that "no plane landed or took off for at least two hours" at Athens, and ERT said that for up to three hours many inbound aircraft were redirected to Turkey.

Panagiotis Psarros, head of the Association of Greek Air Traffic Controllers, described the failure in stark terms: "for some reason, all frequencies were suddenly lost… We could not contact planes in the sky." He called the incident "very serious" and attributed the collapse to problems at the central radio-frequency systems serving the Athens and Macedonia zonal control centres, the largest control hubs in the country.

Operational disruption was broad. Airport statements and on-site observers reported long queues, dozens of cancellations and diversions, and many passengers left stranded in terminals. More than 75 flights were delayed in the initial hours, according to airport tallies. Athens' main international gateway handled 31.6 million passengers in the first 11 months of 2025, underscoring the scale of traffic at risk from even short interruptions.

The civil aviation authority described the outage as unprecedented and said restrictions were imposed as a precaution while technical teams worked to restore communications. By around 1100 GMT air traffic began to resume progressively, though diversions and delays persisted and investigations into the root cause remained under way.

Beyond immediate traveller disruption, the incident raises wider economic and regulatory questions. Short-term costs for carriers can include fuel and diversion expenses and passenger accommodation obligations, while airports face congestion spillovers that can ripple into tourism receipts and business travel, particularly significant for Greece as visitor flows are a major economic driver. The volume of traffic at Eleftherios Venizelos highlights the potential for even brief outages to produce large knock-on effects.

Technical assessments already point to ageing equipment inside national control infrastructure, a vulnerability that could invite accelerated investment or regulatory enforcement. Authorities face pressure to produce a definitive technical and security assessment and to outline a timetable and budget for upgrades that would bolster resilience against equipment failure and potential cyber threats. The incident is likely to prompt closer scrutiny from aviation regulators and to accelerate discussions on redundancy, maintenance cycles and capital spending in the Greek air-traffic management system.

For now, authorities emphasize safety as the guiding principle while crews restore normal communications. Passengers affected by delays and cancellations are being assisted at airports as the investigation into the abrupt frequency loss continues.