A technical failure in Greece's air traffic control communication systems forces authorities to impose a
Israel–Hezbollah conflict — A technical failure in Greece's air traffic control communication systems forces authorities to impose a seven-hour nationwide ground stop and airspace closure, diverting aircraft

Context: Israel–Hezbollah conflict.
A technical failure in Greece's air traffic control communication systems forces authorities to impose a seven-hour nationwide ground stop and airspace closure, diverting aircraft to nearby countries and causing widespread delays and cancellations. [https://vinnews.com/2026/01/04/greek-airspace-disruption-caused-by-air-traffic-control-communication-failure/ ( VINnews )] [https://www.reuters.com/world/europe/greek-airports-halt-flights-due-radio-frequency-issues-2026-01-04/ (Reuters)]
Event summary via Wikipedia Current Events (2026-01-04).