The Hellenic Civil Aviation Authority (HCAA) reported a massive interference incident that disrupted nearly all radio frequencies serving the Athens Flight Information Region (FIR). The incident caused widespread flight delays and airspace restrictions on Sunday morning.

According to the HCAA, this was an unprecedented event due to its scale, geographic reach, and duration.

Continuous Radio Noise Caused Communication Failure

The Authority detected continuous and unintended radio transmissions across multiple frequencies. This “noise” made communication between pilots and air traffic control unsafe.

HCAA technicians, working closely with OTE engineers, immediately began efforts to locate and fix the problem. At the same time, several operational communication lines also failed.

Crisis Management Team Activated Immediately

The HCAA activated its Crisis Management Team early on Sunday. The team met at the Athens Area Control Center under the leadership of HCAA Governor Konstantinos Saounatsos.

Senior air navigation officials and technical directors joined the operation. The team maintained constant coordination with EUROCONTROL to manage air traffic safely.

Emergency Aircraft Deployed to Trace Interference

Later in the day, the HCAA ordered a specialized aircraft to take off on an emergency mission. On board were HCAA electronics engineers and a specialist from the Hellenic Telecommunications and Post Commission (EETT).

Their mission focused on detecting the source of the interference from the air. At the same time, ground teams inspected transmission sites across Greece, including Hymettus, Pelion, Thassos, and Akarnania.

Air Traffic Reduced for Safety Reasons

To protect flight safety, air traffic controllers reduced capacity in the Athens FIR to 35 aircraft per hour. After 16:00 local time, authorities increased capacity to 45 aircraft per hour as systems stabilized.

Air Traffic Controllers Blame Outdated Equipment

The Hellenic Air Traffic Controllers Association described the incident as extremely serious. The union linked the failure to aging and poorly maintained communication systems.

Controllers used all available backup tools to keep aircraft already in Greek airspace safe. Authorities also suspended departures from all Greek airports for flights entering the Athens FIR. When possible, they rerouted aircraft through neighboring FIRs.

Calls for Immediate Investigation

The Association called for an urgent investigation involving the Civil Aviation Authority (APA) and the Air Accident Investigation Authority (EODASAAM). It also demanded a clear timeline for full system restoration.

Controllers warned that similar incidents have occurred before. They pointed to a major communication and radar failure in August 2025 that never led to accountability.

Chaos at Greek Airports, Including Eleftherios Venizelos

Earlier on Sunday, severe disruption affected Athens International Airport “Eleftherios Venizelos” and airports nationwide. Aircraft remained grounded, while arrivals and departures faced long delays.

Airlines worked to reschedule flights, but the disruption affected both domestic and international travel. The impact was especially heavy due to high holiday return traffic.