An investigation has been launched after flights in Greece were grounded for several hours due to national air traffic communications suffering a frequency blackout.
On January 5, 2025, local media agencies in Greece reported that the Head of the Athens Misdemeanor Prosecutor’s Office, Aristidis Koreas, had ordered a preliminary investigation to establish what went wrong.
According to eKathimerini, the probe will be led by the police’s electronic crime team which will look at whether the offence of dangerous interference with aircraft transportation has been committed.
Police will also seek to establish the source of the blackout which impacted almost all frequencies of the Athens Flight Information Region (FIR).
On January 4, 2025, airlines including Aegean Airlines, British Airways, Ryanair and Scandinavian Airlines were forced to cancel or divert flights due to the unprecedented outage.
The Hellenic Civil Aviation Authority (HCAA) explained that a “noise” over radio frequencies resulted in the country’s airspace being temporarily closed.
“The ‘noise’ observed in the frequencies was in the form of continuous, involuntary emission,” said a spokesperson for aviation authority.
Commenting on the disruptions Panagiotis Psarros, Chair of the Association of Greek Air Traffic Controllers, told ERT that all frequencies were “suddenly lost”.
“We could not communicate with aircraft in the sky,” added Psarros.
Greece’s Minister for Infrastructure and Transport of Greece, Christos Dimas, said that the technical issue “did not affect the safety of flights in any way”.
“As soon as the problem was identified, the prescribed procedures were activated both for the safe conduct of flights, in cooperation with EUROCONTROL, and for dealing with the problem at a technical level,” said Dimas.
He added: “Among other things, the systems were checked by the HCAA’s electronics in all the regional transmission and reception system units, while the equipped CAA aircraft took off, extraordinarily, with the Service’s electronics and a special EETT technician and is carrying out a check on the frequency spectrum.”
The Ministry of Infrastructure and Transport is currently implementing a plan to upgrade and modernize Greece’s air navigation systems by 2028.
Announcement: We would like to inform our passengers that the technical issue affecting the radio frequency systems of the Hellenic Aviation Service Provider, which has been ongoing since the early morning hours continues to cause a significant reduction in capacity within Greek…
— Aegean Airlines (@aegeanairlines) January 4, 2026
Thousands of passengers were left stranded following the airspace closure on what is traditionally a very busy day for commercial travel.
At around 17:00 on January 4, 2025, Athens International Airport (ATH) said that the technical problems had been resolved, and flight capacity had been restored.
Greece’s largest carrier, Aegean Airlines wrote on social media: “We would like to inform our passengers that the technical issue affecting the radio frequency systems of the Hellenic Aviation Service Provider, which has been ongoing since the early morning hours continues to cause a significant reduction in capacity within Greek airspace, resulting in flight delays and/or cancellations to and from Greek airports.”
