Bosnian and Croatian airspace to generate notable ATC delays

NEWS FLASH

Eurocontrol has named Bosnia and Herzegovina and Croatia as critical bottlenecks in Europe for air traffic control (ATC) delays as the continent prepares for another summer of widespread ATC disruption. The two have been ranked second and third in Europe for anticipated delays this summer.

Due to the ongoing closure of eastern airspace caused by the Russia - Ukraine conflict, many flights are being rerouted over Bosnia and Herzegovina, considerably increasing traffic volumes compared to pre-pandemic levels. The country’s air navigation service provider BHANSA still has limited sectorisation, which restricts its ability to handle traffic peaks efficiently. BHANSA has also faced challenges in scaling up air traffic controller staffing and training to match the growing demand. The agency has also dealt with technical and regulatory delays in implementing more dynamic traffic flow management tools. Its recent financial issues have further exasperated the situation. Delays are expected in particular during afternoon hours, as well as weekends in July and August. Bosnia and Herzegovina is expected to implement ATFCM (Air Traffic Flow and Capacity Management) regulations more frequently this summer, which could lead to delays cascading across the wider regional network, including Serbia, Croatia, Montenegro and Macedonia.

The Zagreb Area Control Centre (ACC) in Croatia has also been identified by Eurocontrol as a critical ATC bottleneck for this summer. The centre, which oversees the Zagreb Flight Information Region (FIR), is expected to come under intense pressure due to surging seasonal demand, structural limitations and persistent regional traffic rerouting. With around 20% of Eastern European airspace still unavailable due to conflict, air traffic is increasingly concentrated along central corridors, many of which pass directly over Croatia. Delays are anticipated during peak-hour congestion between Friday and Sunday, especially in July and August. While the country’s air navigation service provider Croatia Control has made improvements in dynamic sectorisation, its capacity to expand airspace sectors during peak loads remains limited. Restrictions have already put in place for flights between select countries to overfly Croatia. Eurocontrol’s 2025 planning documents suggest Zagreb may not have enough available air traffic controllers to support full demand scenarios during extended operating windows.

This summer, Vienna Area Control Centre is expected to be the biggest generator of ATC delays in Europe. Apart from Bosnia and Herzegovina and Croatia, Skopje ACC ranks sixteenth for anticipated delays, Belgrade eighteenth and Ljubljana twentieth.