- The flight paths of the Tunisair Airbus A320, which took off from Istanbul bound for Tunis, and the EgyptAir Airbus A320, which departed from Cairo en route to London.
- Everything that happened between 09:01 and 09:19 in the morning involving the two aircraft, which were flying at the same altitude — 36,000 feet.
- What might have happened if air traffic controllers had not managed to establish contact with one of the pilots at the last moment and instruct him to change altitude?
- A detailed account of what the FlightRadar24 system recorded following the collapse of all communications systems in the Athens FIR.
By Aris Chatzigeorgiou
A cross in the sky above the Pindus Mountains. Two dark blue lines that intersected at 9:19 a.m. on Sunday, January 4, 2026 — 20 minutes after the collapse of all communications systems in the Athens FIR. The flight paths of two aircraft that came dangerously close to one another, unaware that the airspace of the European country over which they were flying had been left to operate using “obsolete technology systems no longer supported by the manufacturer, with no capacity to provide meaningful operational guarantees,” as noted in the official report.
Data Journalists unveil a digitally recorded video capturing the conditions in the Athens FIR during the first minutes of the blackout. The footage comes from the Flightradar24 platform, which millions of aviation enthusiasts worldwide who engage in planespotting avidly follow.
Flightradar24 continuously tracks the routes of aircraft around the world, including many military planes. Planespotters, who are hobbyists who track aircraft, flag anything unusual they observe and share it on online forums. One such enthusiast closely followed events in Greek airspace on the first Sunday of 2026. They searched the application’s archives, where all flights remain available for several hours, and identified the near-miss incident. They digitally processed the data so that the aircraft’s flight paths and trajectory traces appeared clearly and separately.
The two-minute video reconstructs what happened between 9:01 and 9:19 a.m., when the two airplanes crossed paths at a safe distance. The pilot of one of the airplanes had been alerted by air traffic controllers and descended to a lower altitude.
Time 09:01: In the first four seconds of the video, we see on the satellite map an airplane highlighted in orange, flying over Sithonia in Halkidiki. It is approaching from the east, and its future flight path is marked by a dark blue line heading west–southwest. The FlightRadar application allows us to identify it as a Tunisair Airbus A320 that took off from Istanbul bound for Tunis. Another crucial detail is the altitude at which it is flying (Barometric Alt), which fluctuates slightly below 36,000 feet (approximately 12,000 meters). The time shown is 07:01 (UTC — Coordinated Universal Time), which corresponds to 09:01 local time.
Time 09:02: At the 9th second of the video, another airplane appears, highlighted in the same orange color and positioned lower on the map. Next to it is a photograph of the aircraft. It is also an EgyptAir Airbus A320 flying toward and preparing to pass over the Corinth Canal. It departed from an area south of Cairo and is bound for London. Its blue flight path indicates that it is heading north-northwest. The airplane is flying at an altitude of slightly below 36,000 feet. The local time in Greece is now 9:02 a.m.
Time 09:03: Under normal circumstances, these two aircraft would be on a collision course a few minutes later over the Pindus Mountains because they are flying at the same altitude, 36,000 feet. In this case, the system would issue an alert and Air Traffic Control would instruct one of the aircraft to climb or descend, depending on what would be best for the other aircraft in the area. However, on that day, this was not possible.
As stated in the official findings of the committee that investigated the blackout, an “extensive disruption, unprecedented in scale, occurred in the communications services of the Athens FIR/Hellas UIR at 08:59, involving the occupation/blocking of frequencies (intense continuous noise) and simultaneous malfunctions in ground-to-ground telecommunications circuits and individual data links.” This failure manifested as “intense noise/whistling,” even on the emergency frequency at 121.5 MHz. Between 09:00 and 09:32, the malfunction expanded to critical climax frequencies (124.625 TAK, 124.025 TYM, and 125.200 TST). There was a complete outage of HellasCom telecommunications lines serving sixteen airports, including Chania, Samos, and Mykonos. Additionally, the feed providing the Hellenic Air Force with situational data from the “ATLAS” information system was interrupted.
Time 09:06: Fourteen seconds into the video, the Tunisair aircraft has moved on from Halkidiki and is now over the open waters of the Thermaic Gulf. By the 20-second mark, the Egyptian aircraft has passed over Corinth and is heading toward the Gulf of Itea.
Time 09:08: Twenty-nine seconds into the video, the Tunisair aircraft approaches Mount Kissavos from the east, leaving the Aegean Sea behind. By the 35-second mark, the EgyptAir Airbus has passed the Gulf of Corinth and is approaching the Roumeli mountains.
Time 09:09: The Tunisair aircraft is now flying over the city of Larissa (00:43 in the video).
Time 09:10: The EgyptAir plane is already over Mount Parnassus (00:51).
Time 09:12: The Tunisair aircraft has passed over Larissa and is heading toward Trikala (01:02).
Time 09:14: This is where the miracle happens. Thirteen minutes into the flight, both aircraft are flying at the same altitude of nearly 36,000 feet. The EgyptAir plane continues northwest and approaches Karpenisi at 1:14 in the video. Meanwhile, the Tunisair aircraft descends to 35,000 feet at 1:21. It is believed that an air traffic controller managed to contact the Tunisair pilot after multiple attempts and instructed him to descend using the emergency frequency. Interestingly, the aircraft descended from 36,000 to 35,000 feet even though standard procedure dictates that westbound planes use “even” altitudes (e.g., from 36,000 to 34,000 feet) and eastbound planes use “odd” altitudes.
Time 09:16: The EgyptAir aircraft is already flying over the Pindus Mountains at 1:33 in the video, while the Tunisair plane is approaching the same area at 1:42, leaving the Thessalian Plain behind.
Time 09:19: The two airplanes converge at the same geographic location (01:53), but fortunately, they are at different altitudes. The Tunisair plane has descended below 35,000 feet.
But what if the air traffic controllers had failed to contact one of the pilots and instruct them to change altitude? Experienced aircraft operators we spoke with pointed out that every modern airplane is equipped with an onboard radar system that formed the basis for the air collision avoidance system, TCAS (Traffic Collision Avoidance System), decades ago.
Each aircraft’s TCAS predicts its own flight path and simultaneously tracks the paths of other aircraft within a 25-mile radius. When a potential collision is detected, the TCAS automatically instructs the pilot to descend while the TCAS on the other aircraft simultaneously commands the plane to climb. Pilots must respond immediately because distances in the air are covered in seconds. In fact, they are required to obey the TCAS’s automatic instructions, even if an air traffic controller issues different orders.
One of the most recent midair collisions occurred on July 1, 2022, over Überlingen, a city in southern Germany. It occurred when an air traffic controller provided incorrect instructions contrary to TCAS guidance, which the pilot of a Russian Tupolev 154 followed. The collision resulted in the deaths of 71 people, including 52 children, as the Tupolev was carrying a school group. In February 2004, a Russian architect who lost his wife and two children in the accident traveled to Switzerland and murdered the air traffic controller responsible for the fatal error.
Although TCAS can prevent a mid-air collision at the last moment, it is not a tool for air traffic regulation. Activating it causes significant disruption, and afterward, all aircraft in the area must reprogram their flight paths.
In short, the TCAS did not activate on the day the Athens FIR turned into a black hole on the global aviation map for hours — but that is no reason for the Greek authorities to celebrate. At 9:58 a.m. that morning, a “zero rate” was imposed over Greek airspace, meaning no aircraft were allowed to fly over the country. Meanwhile, 80 planes were already in the air, and that number was expected to rise to 109 within 30 minutes.
On that Sunday, which would become known as Greece’s aviation Waterloo, the government’s official narrative was that, although they were caught off guard, flight safety was never at risk. This narrative was supported by the Ministry of Infrastructure and Transport committee report rather than the independent EODASAAM investigation authority report. The report states, among other things, that:
- “Based on the reports received, no separation minima infringement was declared.”
- “According to reports on the ECCAIRS platform and the Civil Aviation Authority’s (CAA) assessment, the incident was classified as low risk (green area) and did not involve a minima separation violation.”
- After reports were submitted to the ECCAIRS Incident Management platform, the Civil Aviation Authority (CAA) used the EASA Risk Assessment Method (ERCM) to classify the incident as low risk for flight safety, or green. The initial safety barrier used was regulation and procedure, as confirmed by the reports. The reports note that the air navigation personnel demonstrated a timely operational response and applied the prescribed procedures, which contributed to maintaining the safety level. The reports also note that the aircraft operators implemented the appropriate contingency plan.
- All of the above means that no aircraft came within 10 miles of another. However, based on the video, the only certainty is that the two planes were flying at different altitudes, 1,000 feet (approximately 300 meters) apart. Only an independent committee could determine whether the distance between the nose of one aircraft and the tail of the other was indeed more than 10 miles.
