Today, January 6, the Special Committeewhose task is to clarify the exact causes of the problem that occurred on Sunday, January 4, 2026, on the frequencies of the Athens F.I.R.met with the Administration and the competent officials of the Hellenic Civil Aviation Authority (HCAA) at the Athens & Macedonia Area Control Center (KEPATHM).
During the meeting, an in-depth discussion took place on the technical parameters of the incident, in order to record all aspects of the issue, the actions taken, and ultimately to shed light on the root causes.
According to the HCAA, procurement of new transmitter-receiver systems and VCS systems is currently underway. More specifically:
Procurement of 495 new VHF VoIP transmitter-receivers from ROHDE & SCHWARZ HELLAS S.A., with a contract value of 4.2 million. The contract was signed on 20/10/2025, and delivery of the first systems is expected within the first two months of 2026, after which they will be installed by HCAA electronic engineers.
New VCS/RCS for KEPATHM, with SPACE HELLAS as contractor and a contract value of 4.7 million. A decision from the Hellenic Court of Audit regarding the amendment of the contract is expected on 13/01/2026.
Regarding the incident of January 4, 2026, the Authority states:
the immediate technical and operational response and the professionalism of HCAA personnel, and especially the Air Traffic Controllers and Electronics Engineers, made it possible to maintain flight safety and ensure proper operational and technical handling.
What happened on Sunday
Regarding the problem in the FIR, the HCAA reports the following:
On 4 January 2026 at 08:59 local time, the HCAA faced a technical problem in the form of continuous noise interference in frequency reception, originating from excitations (unintentional signal emissions) from the Authoritys transmitters, as indicated by the initial investigation. This simultaneously affected multiple frequencies serving the Athens F.I.R., while at the same time there was a malfunction in the telephone interconnection lines and the HELLASCOM data circuits.
Both the primary and secondary (backup) Voice Communication Systems (VCS) and transmitter-receivers were operational throughout the incident. However, the noise interference blocked the frequencies.
By order of the HCAA Governor, the Crisis Management Team was immediately convened at the Athens Area Control Center (KEPATHM), with the participation of the Deputy Governor for Air Navigation, the Director General of Air Navigation, and the Heads of all competent Directorates. The Team remained in constant coordination and communication with external bodies and the political leadership of the Ministry of Infrastructure and Transport.
With flight safety as the guiding principle, and in close cooperation with EUROCONTROL for optimal traffic management in the Athens F.I.R., Air Traffic Control initially proceeded with the evacuation of the Athens F.I.R. After 12:00, operational activity in the Athens F.I.R. began to be gradually restored, depending on operational conditions and frequency availability, in order to reduce the impact on airports and passengers. To this end, relevant NOTAMs were issued for the official information of the aviation community.
From the onset of the incident, coordinated investigation and restoration actions were carried out, both within the HCAA network and the systems of KEPATHMparticularly the VCS and Remote Control System (RCS)as well as within the telecommunications infrastructure of the provider (OTE). HCAA electronic engineers were mobilized at all relay stations, including Hymettus, Pelion, Thasos, Acarnanian Mountains, Monastiri, Corfu, Rhodes, and Geraneia, in order to carry out on-site system inspections. The inspections were completed late on Sunday evening, without yielding any findings directly linked to the incident.
In addition, by order of the Governor, the specially equipped HCAA aircraft took off, with the participation of HCAA electronic engineers and a specialized technician from the Hellenic Telecommunications and Post Commission (EETT), to conduct targeted airborne frequency spectrum investigation. No active emissions were recorded that could be linked to the technical problem.
For the in-depth analysis of the cause of the problem (root cause), the HCAA remains in close cooperation with OTE at all levels, within the framework of cross-checking the cause of the incident and coordinated technical assessment. The investigation so far appears to locate the problem within telecommunications infrastructure and has not revealed any evidence of a cyberattack on HCAA systems.
The frequencies of the Athens F.I.R. and the operational communication telephone systems were fully restored by 17:00. Airspace capacity and air traffic flow returned to normal levels by 17:45.
The simultaneous occurrence and restoration of failures across different technical domains and distinct, non-interconnected systems (e.g. VCS, telephone and analog lines, HellasCom lines) characterizes the unprecedented nature of the phenomenon.
