Capacity - Croatia
PRB monitoring
Croatia registered 0.38 minutes of average en route ATFM delay per flight during 2025, which has been adjusted to 0.42 during the post-ops adjustment process, thus not achieving the local target value of 0.29. Delays in Croatia decreased by -1.09 minutes per flight year-on-year. Delays were highest in July and August, mostly driven by weather and ATC capacity.
The share of delayed flights with delays longer than 15 minutes in Croatia decreased by -9 percentage points compared to 2024, but was higher than 2019 values.
The number of ATCOs in OPS was 108, being below the 2025 plan in Zagreb ACC by -7 FTE.
The yearly total of sector opening hours in Zagreb ACC was 40,409, showing a 6% increase compared to 2024.
Zagreb ACC registered 23.61 IFR movements per sector opening hour in 2025, 2% above the 2024 level.
En route performance
En route ATFM delay (KPI#1)
NoteFocus on en route ATFM delay
En route ATFM delay
Croatia had 1,001k flights in 2025, up from 922k flights in 2024.
Croatia Control applied en route ATFM regulations resulting in 383k minutes of delay, a significant reduction from the 1 459k minutes in 2024.
As part of the strategic traffic re-orientation programme (S25/NTDM) operated by the Network Manager, there were 31k minutes of en route ATFM delay reattributed to Croatia Control; 3k minutes of delay originating in Croatia were re-attributed to other ANSPs.
Under the auspices of the Route Network (RN) Scenarios during Capacity & Weather Based Operations between June and September 2025, there were 10k minutes of en route ATFM delay re-attributed to Croatia; 4k minutes of delay originating in Croatia, were re-attributed to other ANSPs.
When the above post-operations re-attributions are factored in, the total en route delay for Croatia Control in 2025 was 414k minutes in 2025 down from 1,390k minutes in 2024.
Regarding the reasons and circumstances resulting in the achieved level of actual performance of the en route ATFM delay per flight KPI, the NSA reports: “The Single European Sky Data Portal is the primary information source and is used to monitor all available KPIs and PIs.
In 2025, traffic within the LDZO ACC increased by 8.7%, reaching levels consistent with high traffic forecast scenarios for the third consecutive year and significantly exceeding the RP4 Performance Plan forecast. Despite this sustained and above-forecast traffic growth, LDZO ACC achieved a 74% reduction in delay compared to the elevated delay levels recorded in 2024.
Nevertheless, the continued increase in demand—particularly along the South-East axis—resulted in capacity constraints during the summer season, driven by unplanned peaks in traffic during high-intensity periods. In addition, national demographic measures adversely affected the availability of operational resources, impacting adequate staffing during the peak summer period.
As a consequence, the en-route delay target was marginally missed by 0.13 minutes per flight.”
Regarding the description of the adjustments to the capacity plan included in adopted performance plan, the NSA reports: “The ANSP continuously updates its capacity plans in response to dynamic changes in traffic demand, in line with the collaborative decision-making (CDM) approach applied during the annual NOP planning process.
Given that traffic growth is anticipated throughout the RP4 period, the ANSP regularly revises its capacity-related parameters to accommodate forecasted demand levels.”
Regarding the identification and analysis by the NSA of the underlying reasons or circumstances having led to the performance target not being achieved, the NSA reports: “The NSA holds biannual meetings with the ANSP to assess the implementation and fulfilment of activities defined in the ERNIP and NOP. These meetings serve as a structured mechanism for monitoring progress and ensuring alignment with the network objectives.
During 2025, traffic levels in six out of twelve months increased by more than 10%, while the remaining six months also recorded traffic growth within the single-digit range. This trend further intensified the operational demands placed on the Croatian airspace system and confirmed the continuation of sustained traffic growth throughout the year.
At the same time, the period of elevated traffic demand has expanded from the traditional peak summer months to a period exceeding six months in duration. Such prolonged and sustained traffic intensity creates additional challenges in air traffic flow and capacity management, requiring continuous operational adaptation and enhanced resource coordination.
Furthermore, the significant increase and extension of traffic demand considerably reduces the operational margins available to absorb unforeseen disruptions and short-term variations that are inherently associated with the human factor, including sick leave, and other unavoidable staff absences. Under these conditions, maintaining operational resilience during prolonged peak periods represents an increasingly demanding challenge for the ANSP.”
Regarding recommendations to the ANSP to rectify the situation, the NSA reports: “None”
Regarding remedial measures that have been / will be taken by the ANSP to rectify the situation, the NSA reports: “Continuous improvements to the rostering system were implemented with the objective of increasing operational flexibility and optimising the utilisation of available ATCO's. In addition, a new concept for the composition of ATCO teams was introduced, enabling a more efficient deployment of operational staff and creating additional capacity for the opening of supplementary sectors in response to operational requirements and increasing traffic demand.
Furthermore, dedicated ATFCM awareness workshops were conducted in order to strengthen operational understanding, improve coordination processes, and enhance proactive traffic management practices across operational units.
To further support tactical traffic management and operational decision-making, an additional morning MET briefing was introduced prior to the start of the first operational rotation. This measure ensures that traffic management activities can be initiated at the earliest stage based on the most up-to-date meteorological and operational information available, thereby contributing to improved traffic predictability and network performance.”
Regarding follow up of the remedial measures indicated in the previous monitoring report(s), the NSA reports: “The ANSP implemented all recommended NOP remedial measures for the 2025 summer season. However, the continued and above-forecast traffic growth along the South-East axis significantly impacted capacity performance and contributed to the marginal non-achievement of the Capacity KPA target.”
En route capacity incentive scheme
The Croatian NSA reports a financial penalty of €124,232 for the ANSP because of the 2025 performance. The local incentive target for en route ATFM delays, due to CRSTMP causes only, was set at 0.141 mins/flight. The NSA reports an achieved performance of 0.159 mins/flight and refers to the SES Data Portal (ansperformance.eu) as being the primary source to monitor all KPIs & PIs.
[NB The attribution of original delay causes on the ansperformance.eu dashboard is unverified]
En route performance indicators at ACC level (PI#4-5)
NoteFocus en route performance indicators at ACC level
Percentage of total en route ATFM delay that occurred on days when the daily throughput was above the expected daily traffic
As background information on actual performance, the NSA reports: “According to Network Manager dashboard data, the ANSP recorded 29.2% of total en-route ATFM delay on days when daily throughput exceeded expected traffic levels (ACC). Local data indicate an even higher proportion than that reflected in the NM dashboard.
The occurrence of delays under conditions where throughput surpassed expected demand can be attributed to a combination of factors, including the impact of geopolitical developments (notably in Ukraine and the Middle East), sustained pressure on South-East axis ANSPs to accommodate high traffic volumes, adverse weather conditions across the network, and the influence of neighbouring ANSPs’ operational performance.”
Annual weighted average of the daily peak throughput
As background information on actual performance, the NSA reports: “The PI”Annual weighted average of the daily peak throughput (ACC)” provides only a partial representation of the ANSP’s capacity delivery, as it captures performance over a limited three-hour peak period, while capacity provision during the remainder of the operational day is not reflected.
As 2025 represents the first monitoring year for this indicator, the achieved result should be interpreted with caution, as it does not yet provide a fully representative assessment of overall capacity performance.”
NoteFocus on other en route information
ATCOs in operations
As additional comments to ATCOs in the scope of the performance scheme, the NSA reports: “Operational ATCO availability is affected by national demographic policy measures in Croatia, including statutory paternity leave (up to 20 working days per child) and parental leave entitlements that may be exercised until the child reaches the age of eight. The higher than planned non-duty hours in 2025 reflect primarily extended sickness leave and increase of the paternity leaves, coupled with planned reinforcement of refresher training in response to traffic growth and increasing operational complexity.”
“Please note that, as required, the number of additional ATCOs in OPS is presented here in terms of Full-Time Equivalents (FTEs). In 2025, 12 new ATCOs began working as ACC ATCOs in OPS (out of which 2 renewals). However, since most of them obtained their licenses in late 2025 (October), they cumulatively increased the FTE count by a significantly lower amount. At the same time, during 2025, two ACC ATCOs lost their licenses, resulting in a 0.41 decrease in FTEs.”
Regarding the training process, including details on the effective failure rate and the process used to allocate newly qualified ATCOs between ACC, APP and TWR positions, the NSA reports: “CCL ATCO TO provides training pursuant to the Commission Regulation (EU) 2015/340 including applicable Acceptable Means of Compliance (AMC) for: Basic Training, Rating Training for ADC, APS and ACS and Unit Training for 16 different locations. Duration of training (Initial and Unit) for ADC and APS is up to 2 years. Duration of training for ACS is approximately 2.5 years. Hereby presented numbers represents only ATCO trainees in the scope of the performance plan (i.e. ACS and APS). The number of ATCO trainees at year end is affected by a slightly lower than expected success rate of generation 2024, as well as delayed ATCO Additional (EU) employments planned in 2025.”