Athens air traffic controllers managed a sudden radar outage Thursday that crippled frequencies for incoming and outgoing flights. The Association of Greek Air Traffic Controllers said the glitch hit Athens Approach, the unit that guides planes around the airport.

Staff relied on a single remaining radar after data transfer from Merenta Hill stopped completely. Normally, three radars run simultaneously with backup frequencies. Controllers had no such backups during the failure, according to the association.

“This is not the first time that the data link with Merenta Hill has failed,” the group stated in a release. It pointed to a similar disruption last August. Civil Aviation authorities had promised fixes after that episode, but the problem returned.

The association praised its members for safely landing all aircraft despite the equipment failure. Controllers stepped in as the sole safeguard, it said. Still, the group warned that repeated breakdowns threaten safety.

To protect passengers, staff plan “all necessary measures, including reducing capacity,” the association announced. No details emerged on the outage’s duration.

The incident follows a larger airspace shutdown just over a month ago. Greek authorities halted all flights nationwide after radio frequencies collapsed entirely. Thousands of travelers sat stranded. Airports across the country ground to a halt for hours.

Officials continue probing Thursday’s radar loss. Air traffic controllers cite aging infrastructure as the root cause. The association called out Civil Aviation Authority management and directors for exposing operations to known risks.

Athens International Airport handles heavy summer traffic. The radar at Merenta Hill provides critical data for Approach control. Losing it forces controllers to improvise with limited tools.

Industry experts have long flagged Greece’s air traffic systems as outdated. A European Union audit last year urged upgrades to radars and communications. Funding delays have slowed progress, sources said.

The Civil Aviation Authority has not commented publicly on Thursday’s event. It previously assured fixes after August’s failure. Controllers now demand immediate action to prevent repeats.

Safety records at Athens remain strong. Controllers’ quick thinking averted delays or worse on Thursday. But the association insists equipment must match the workload.

Greece’s tourism boom fills skies with charter flights. Any glitch risks chaos at a gateway like Athens. Travelers last month endured hours of uncertainty from the radio collapse.

Unions across Europe watch closely. Similar strains hit control towers in Spain and Italy this year. Aging tech plagues the sector amid rising air travel.