Greek authorities are investigating an unprecedented blackout in the Athens Flight Information Region (FIR) that disrupted air traffic control operations for several hours this month, exposing what aviation professionals describe as severely outdated and vulnerable infrastructure.
The incident, which Greece’s Civil Aviation Authority (HCAA) described as “dangerous and unprecedented,” prompted a judicial investigation ordered by the Athens prosecutor’s office and a sworn administrative inquiry launched by the aviation authority at the request of Infrastructure and Transport Minister Christos Dimas.
A special investigative committee set up by the HCAA said in a preliminary statement that the problem appears to be linked to telecommunications infrastructure and that there is, so far, no evidence of a cyberattack on the authority’s systems.
The blackout affected multiple radio frequencies across the Athens FIR, one of Europe’s busiest airspaces, raising concerns among air traffic controllers and pilots about the resilience of Greece’s air navigation systems.
Air traffic controllers say failures linked to ageing equipment are a daily occurrence. Transmitters, receivers and radar systems currently in use are decades old and have been repeatedly exposed to harsh weather conditions, according to union representatives.
“The system is around 30 years old, far beyond its intended lifespan for aviation,” said Olga Toki, an air traffic controller and vice president of the controllers’ union. “Frequencies drop, systems malfunction, and outages are constant.”
Aviation professionals said the radar systems are also obsolete, increasing operational risk during partial or complete failures. While aircraft are equipped with onboard collision-avoidance systems, pilots said prolonged communication outages heighten concerns over fuel management and landing safety.
“The anxiety is not so much about collisions,” said a pilot at a major airline. “It’s about how long aircraft can remain airborne without clear instructions and whether there will be sufficient fuel to land safely.”
Grigoris Konstantellos, a pilot and mayor of Vari–Voula–Vouliagmeni, said the scale of the incident was exceptional. “An entire FIR losing multiple frequencies for hours is something rarely seen globally,” he said, adding that Greece’s last major investment in radio systems dates back to the late 1990s.
Minister Dimas said modernization of air traffic control systems at Athens International Airport is planned to be completed by 2028, following years of underinvestment.
According to aviation officials, the investigation into the blackout is ongoing, as authorities seek to determine the precise cause and assess whether further safeguards are needed to prevent similar incidents.