The blackout in the Athens Flight Information Region (FIR), which occurred on Sunday, 4 January, has been attributed to "digital noise" caused by desynchronisation across a range of heterogeneous systems and interfaces leading to the Athens-Macedonia Area Control Centre.
According to the experts’ report, this resulted in the inadvertent activation and continuous transmission of a critical number of transmitters, as well as the degradation or interruption of essential telecommunications links.
The report also noted that there was no evidence of a cyberattack or external malicious interference.
Full restoration, the report states, was achieved following resynchronisation and system restarts after traffic was rerouted through the backbone network. The findings were submitted on Tuesday to the Minister of Infrastructure and Transport Christos Dimas.
For flight safety reasons, according to a statement from the Ministry of Infrastructure and Transport, full capacity restrictions (zero rate) were imposed and emergency procedures were implemented. Service restoration was gradual, with complete recovery achieved at 16:53 local time following voluntary action by the telecommunications provider.