According to CNN and Defence Express, a Russian drone entered Romanian NATO airspace near Chilia Veche, Tulcea County, on 13 September 2025, flew approximately 10 km inside the border, and loitered for approximately 50 minutes before returning toward Ukraine. Two Romanian F-16 fighters and two German Eurofighters from the NATO air-policing mission were scrambled. The 50-minute loiter was described by analysts and officials as the longest confirmed NATO airspace violation by a Russian drone to that date. Ukrainian President Volodymyr Zelenskyy described the event as "a deliberate expansion of the war," adding it to his list of incidents in which Russia was using drone flights over NATO territory to probe the Alliance's response thresholds. AirVeto's wind reconstruction at 900 hPa covers the Danube Delta corridor during the overnight window of 13 September 2025.
Illustrative file photo. This image is not from the incident described β it shows a military-type UAV of the kind found in field recovery operations.
50 minutes inside NATO airspace β why the drone was not shot down
The central operational question is why four NATO jets β two F-16s and two Eurofighters β scrambled in response to the incursion but did not destroy the drone during its 50-minute loiter. The answer is a combination of legal constraints, rules of engagement, and the drone's small radar cross-section.
NATO's rules of engagement for air-policing missions over Alliance airspace require that a violating aircraft be identified, tracked, and escorted β not destroyed on first contact. Shooting down a drone over Romanian territory carries the risk of debris falling on civilians. The drone's low altitude and slow speed (typical of Shahed-class vehicles: approximately 185 km/h, cruise altitude 50β200 m) made it challenging to maintain radar lock in the Danube Delta terrain. And the duration of the loiter β 50 minutes β suggests the drone was deliberate in its pattern, possibly hovering over one location to collect imagery or signals.
Chilia Veche β the Danube Delta entry point
Chilia Veche is a village in Tulcea County at the northern arm of the Danube Delta, directly across the river from Ukraine. The Ukrainian bank of the Danube at this point is Kiliya, Odesa Oblast β the same stretch of river from which dozens of drone and missile fragments have been recovered in Romania since 2022. The Romanian bank here is within 500β1,000 m of Ukrainian territory, making it the easiest NATO airspace to reach from Ukraine-adjacent launch points.
The 10 km penetration puts the drone's deepest point at roughly the level of the SfΓ’ntu Gheorghe arm of the delta β a zone of marshland and water channels with very low population density, which may explain the absence of any intercept decision.
Zelenskyy: "deliberate expansion of the war"
President Zelenskyy's characterisation of the event as "deliberate" was unusual in that Ukraine has generally attributed its own drones' entry into NATO airspace to Russian EW jamming rather than intent. In the case of the Chilia Veche loiter β where the drone was Russian and loitered for 50 minutes before returning β the characterisation of intent is unambiguous. Zelenskyy's statement positioned the event as Russia testing whether NATO would fire on its drones even when they were operating inside Alliance territory.
Wind layer β 900 hPa over the Danube Delta on 13 September
AirVeto's wind reconstruction covers the 900 hPa pressure level (approximately 1,000 m) over the Danube Delta during the overnight window of 13 September 2025. The embed above renders the wind field; methodology is described on the AirVeto methodology page.