Cost-efficiency - Belgium

PRB monitoring

The en route 2025 actual unit cost of Belgium-Luxembourg was 91.28€2022, -5.9% lower than the determined unit cost (97.00€2022). The terminal 2025 actual unit cost of Belgium was 258.69€2022, -2.2% lower than the determined unit cost (264.46€2022).
The en route 2025 actual service units (2.73M) were +1.5% higher than the determined service units (2.69M).
The en route 2025 actual total costs were -11.7M€2022 (-4.5%) lower than determined with all cost categories registering lower-than-planned costs, except staff costs. The gap is mainly due to lower other operating costs of Skeyes (-9.2M€2022, or -27.6%). The NSA attributed this decrease to lower maintenance and external support costs than planned.
A deviation from the criteria to achieve capacity targets was considered justified for Belgium-Luxembourg. Actual costs for the measures necessary to achieve those targets were lower than determined (-1.8M€2022, or -9.7%), mainly due to lower depreciation (-1.8M€2022, or -83.5%) than planned.
Skeyes spent 19.2M€2022 in 2025 related to costs of investments for both en route and terminal charging zones, -5.4% less than determined (20.3M€2022). According to the NSA, this reduction is mainly due to project delays and postponements, as well as lower costs for IT and data equipment.
The en route actual unit cost incurred by users in 2025 was 102.11€ (-3.2% below the 2025 DUC). The terminal actual unit cost incurred by users was 215.63€ (-25.1% below the 2025 DUC) for Belgium and 275.46€ (-14.9% below the 2025 DUC) for Luxembourg. The difference between the AUCU and the DUC for the terminal charging zones is mainly driven by other revenues.
The en route regulatory result for skeyes amounted to +17.5M€, or 10.0% of the 2025 revenue. This may indicate that the airspace users are charged for costs which have not materialised in 2025.

En route charging zone

Unit cost (KPI#1)

Total costs - nominal (M€)	2025	2026	2027	2028	2029
Actual and determined data
Determined costs	284.0	293.6	312.8	321.0	324.6
Actual costs	270.8	NA	NA	NA	NA
Difference costs	-13.2	NA	NA	NA	NA

Inflation assumptions	2025	2026	2027	2028	2029
Determined inflation rate	3.2%	2.1%	2.1%	2.0%	1.9%
Determined inflation index*	110.1	112.5	114.8	117.1	119.4
Actual inflation rate	3.0%	NA	NA	NA	NA
Actual inflation index*	109.9	NA	NA	NA	NA
Difference inflation index (p.p.)	-0.2	NA	NA	NA	NA
*100 = 2022

Focus on unit cost

AUC vs. DUC

In 2025, the en route AUC was -5.9% (or -5.72 €2022) lower than the planned DUC. This results from the combination of lower than planned en route costs in real terms (-4.5%, or -11.7 M€2022) and higher than planned TSUs (+1.5%).

En route service units

The difference between actual and planned TSUs (+1.5%) falls inside the ±2% dead-band. Hence, the gain of additional en route revenues is kept by the ANSPs.

En route costs by entity

Actual real en route costs are -4.5% (-11.7 M€2022) lower than planned. This is the result of lower costs for the main ANSP, skeyes (-6.7%, or -10.7 M€2022), the other ANSPs (ANA and MUAC, -0.9%, or -0.8 M€2022), the NSA/EUROCONTROL (-1.3%, or -0.2 M€2022) and the MET service provider (-3.8%).

En route costs for the main ANSP (skeyes) at charging zone level

Based on the additional information to the en route reporting tables, the significantly lower than planned en route costs in real terms for skeyes in 2025 (-6.7%, or -10.7 M€2022) result from:

Slightly lower than planned staff costs (-0.7%), mainly due to lower than foreseen salary increases, including indexation and merit increases.
Significantly lower than planned other operating costs (-27.6%), mainly due to lower than planned maintenance costs and external support costs.
Lower than planned depreciation (-3.2%), mainly due to lower depreciation costs for IT infrastructure network, systems and data centres, as well as IT communication radio assets.
Significantly lower than planned cost of capital (-8.4%), mainly due to a lower than planned asset base.

Assessment of the actual performance in the charging zone reported by the NSA

The NSA provides the following overall assessment of the actual performance in 2025 at charging zone level:

“Overall, actual performance at charging zone level is favourable compared to budget, with underspending in operating costs and lower capital costs in both skeyes and MUAC largely offsetting slightly higher staff costs, while delays in investments have contributed to lower depreciation and cost of capital”.

Explanation of the differences between actual and determined costs at charging zone level reported by the NSA

The NSA provides the following explanation for the differences between actual and determined costs in the charging zone:

” ANSP: skeyes

1.1 Staff costs: The staff costs for En route are slightly below the budget due to lower than foreseen salary increase (index, merit).

1.2 Other operating costs: Other operating costs represent 72% of the budget foreseen in 2025. The underspent is driven by lower maintenance and lower external support costs versus budget.

1.3 Depreciation: The depreciation costs are 339k€ below budget: 97% of planned costs have materialized. We have lower costs for IT infra network, system & datacenter as well as IT com radio.

1.4 Cost of capital: The cost of capital is lower than foreseen in the budget, mainly due to a lower fixed asset base

ANSP MUAC

1.1 Staff costs: for MUAC BE LUX in 2025 (€69.8M) were slightly above the RP4 plan (+1.3%), mainly due to higher salary indexation, partly offset by fewer FTEs. Compared to 2024, staff costs decreased by 8.9% due to the absence of a one off reward paid in 2024.

1.2 Other operating costs: were 15.9% below plan thanks to cost containment, though slightly higher than 2024 due to increased spending on systems, security, and maintenance.

1.3 Depreciation: was lower than planned due to delays in investments but remained close to 2024 levels.

1.4 The cost of capital: was below plan due to lower interest rates but increased versus 2024 due to higher borrowing linked to renewed investments.

ANSP: ANA

Staff costs were slightly higher than initially forecasted for the RP4 performance plan. ANA had estimated an average age of retirement at 59 years for staff working on shifts (ATCOs, etc...) and 62 for other staff. Since the departure rate in 2025 did not materialise as forecasted, the overall staff costs have increased by 500kEUR.

Depreciation costs are higher, as some projects have been activated during 2025 (investment costs stemming from 2018 onwards, where the activation was not foreseen by now) and as investments from 2025 were activated during the year instead of only at the end of the year.”

Recommendations formulated by the NSA to the ANSP (skeyes) to rectify the situation and actions taken by the ANSP

The NSA 2025 monitoring report indicates the following recommendations formulated by the NSA:

“Lack of time between the delivery of the data from the ANSPs and the deadline for submission did not allow an analysis of the situation”.

No action is reported by skeyes in the NSA 2025 Monitoring Report.

Actual unit cost incurred by the users (AUCU) (PI#1)

	€/SU
AUCU components (€/SU) – 2025
DUC	105.46
Inflation adjustment	-0.18
Cost exempt from cost sharing	-0.61
Traffic risk sharing adjustment	0.00
Traffic adjustment (costs not TRS)	-0.13
Financial incentives	0.00
Modulation of charges	0.00
Cross-financing	0.00
Other revenues	-0.50
Application of lower unit rate	-1.93
Total adjustments	-3.35
AUCU	102.11
AUCU vs. DUC	-3.2%

Cost exempt from cost sharing by item - 2025	€'000	€/SU
New and existing investments	-1,421.0	-0.52
Competent authorities and qualified entities costs	-71.3	-0.03
Eurocontrol costs	-157.0	-0.06
Pension costs	-12.4	0.00
Interest on loans	0.0	0.00
Changes in law	0.0	0.00
Total cost exempt from cost risk sharing	-1,661.6	-0.61

Focus on AUCU

En route AUCU monitoring at charging zone level

The actual en route unit cost incurred by airspace users (AUCU) in respect of activities performed in 2025 (102.11 €) is -3.2% lower than the nominal DUC (105.46 €) which includes DUC initially charged: 112.72 €, and DUC to be charged retroactively: -7.26 €. The difference between the AUCU and the DUC (-3.35 €/SU) is due to:

the negative inflation adjustment resulting from lower than planned inflation (-0.18 €/SU);
the impact of adjustments resulting from the costs exempted from cost sharing mechanism (-0.61 €/SU);
the deduction of the traffic adjustment (-0.13 €/SU) for the costs not subject to traffic risk sharing;
the deduction of other revenues (-0.50 €/SU); and
the application of a lower unit rate as foreseen in Art. 29(6) in year 2025 (-1.93 €/SU).

The share of the regulatory result (see next sub-section) in the AUCU (before the deduction of other revenues) is 6.9%.

Initiatives implemented or planned that will improve this PI reported by the NSA

The NSA provides the following information regarding the initiatives:

“Lack of time between the delivery of the data from the ANSPs and the deadline for submission did not allow an analysis of the situation”

Regulatory result (RR)

Focus on regulatory result

skeyes net gain/loss on activity in the Belgium-Luxembourg en route charging zone in 2025

Skeyes reported a net gain of +13.3 M€, as a combination of a gain of +10.8 M€ arising from the cost sharing mechanism, with a gain of +2.5 M€ arising from the traffic risk sharing mechanism.

skeyes overall regulatory result (RR) for the en route activity

Ex-post, the overall RR, taking into account the net gain from the en route activity mentioned above (+13.3 M€) and the actual RoE (+4.3 M€), amounts to +17.5 M€ (10.0% of the en route revenues). The resulting ex-post rate of return on equity is 33.3%, which is much higher than the 8.1% planned in the PP. See also Note 1 below.

Note 1

The ex-post RR for en-route does not take into account the application of the lower unit rate as per Art. 29.6 (loss of revenue amounts to -3.3M€ for 2025).