Athens Airpot Blackout Due to Digital Noise Not Cyberattack

An expert committee has concluded that the communications blackout affecting the Athens Flight Information Region (FIR) on Sunday, January 4, 2026, was caused by “digital noise” resulting from system desynchronisation, according to an official report submitted to Infrastructure and Transport Minister Christos Dimas.

The findings attribute the incident to desynchronisation across multiple heterogeneous systems and interfaces converging at the facilities of the Athens Area Control Centre (KEPATHM). This led to the unintended activation and continuous transmission of a critical number of transmitters, ultimately degrading or interrupting key telecommunications links.

The report stresses that no indications of a cyberattack or external malicious interference were identified.

According to the committee, full restoration of services was achieved following system resynchronisation and restarts, after air traffic was rerouted through the core network. The Ministry of Infrastructure and Transport noted that, for flight safety reasons, a full capacity restriction (zero rate) was imposed and emergency procedures were activated.

Service restoration occurred gradually, with full recovery completed at 16:53 local time following deliberate action by the telecommunications provider.

Based on reports submitted to the ECCAIRS platform and an assessment by the Hellenic Civil Aviation Authority (HCAA), the incident was classified as low risk (Green Area), with no reports of breaches of minimum aircraft separation standards. The committee also confirmed that no aviation safety issue was identified in terms of aircraft being exposed to direct or indirect risk.

The report highlights structural weaknesses in the existing Voice Communication System (VCS) of the Hellenic Civil Aviation Authority and the critical telecommunications infrastructure supporting it. These systems rely on outdated Synchronous Digital Hierarchy (SDH) technology, which is no longer supported by the manufacturer and lacks operational guarantees.

The committee issued a series of recommendations, including accelerating the transition to Voice over IP (VoIP) technology through the procurement, installation, and operational deployment of a new Voice and Radio Communication System (VCS/RCS) and 495 new transceivers. It also called for the establishment of a permanent joint rapid-response mechanism between the HCAA and OTE, enhanced telemetry and remote monitoring capabilities, stronger radio spectrum oversight by the Hellenic Telecommunications and Post Commission (EETT), and the relocation of KEPATHM facilities to a more suitable environment to reduce systemic operational risks.

The investigation committee was chaired by the Governor of the Hellenic Civil Aviation Authority, Christos Tsitouras. Members included the Governor of the National Cybersecurity Authority, Michalis Bletsas; Colonel Dimitrios Zampakolas, a communications engineer from the Hellenic National Defence General Staff; Nikos Igoumenidis, Deputy Director for Spectrum Supervision at the EETT; and a representative of EUROCONTROL. A representative of the European Union Aviation Safety Agency (EASA) participated as an observer.

The committee identified the Hellenic Civil Aviation Authority and the Hellenic Telecommunications Organisation (OTE) as the entities involved in the incident, from which it requested and received official reports, while also evaluating information obtained through interviews with staff from both organisations.