People stand with their luggage, as airports across Greece have suspended arrivals and departures on Sunday, after unspecified issues affecting radio frequencies, at the Eleftherios Venizelos International Airport, in Athens, Greece, January 4, 2026. REUTERS/Louiza Vradi
ATHENS, Jan 14 (Reuters) - An eight-hour radio outage at Greek airports last week that forced authorities to clear the country's airspace and divert dozens of incoming flights was in part due to an outdated communications system, investigators said in a report.
Flights were suspended into and over Greece on January 4 when air traffic controllers lost contact with most planes, including dozens heading for Greek airports,as radio frequencies went down and were replaced by static.
Aviation experts said the incident was unprecedented in the southern European country.
The exact cause of the outage, which occurred when multiple systems fell out of sync, causing a scramble in communications between airport towers and planes, remains unclear, the report from a five-member investigating committee commissioned by the government found.
It ranked the incident as "low risk" regarding flight safety, ruled out a cyberattack and said thatpilots and air traffic controllers responded effectively.
However, the Civil Aviation Authority's voice communication system and critical supporting telecommunications infrastructure are based on outdated technology that is no longer supported by manufacturers and lacks operational guarantees, according to the report, which was submitted to Greece's transport ministry and published late on Tuesday.
The report said that Greek telecommunications provider OTE had since 2019warned the civil aviation authority that its systems needed new circuits. The report called for upgraded transceivers and other changes. It also recommended the creation of a crisis-response mechanism between the civil aviation authority and OTE.
Greece's systems are in line with EU standards, a transport ministry official said in reaction to the report, although the ministry has implemented an upgrade plan expected to be completed in 2028.
But unions, who have been calling for upgrades for years, say the system is dangerous, especially amid a tourism boom with millions of tourists flying to Greece every year. On Wednesday, they said that the report "fully vindicates" their protests.
(Reporting by Renee Maltezou; Editing by Edward McAllister and Sharon Singleton)
