ECJ: Dublin airport passenger cap may limit slot allocation

About this case:

• Citation:
  Case C 857/24, EU:C:2026:855
• Judgment:
  External link
• Court:
  European Court of Justice

Delivering judgment in October, the European Court of Justice confirmed that “during slot allocation, account must be taken of constraints such as the 32mppa condition and that such constraints may have the consequence that some series of slots can no longer be allocated.”

Background

Since 2007, Dublin airport has been designated as a ‘coordinated airport’ within the meaning of Article 2(g) of Council Regulation (EEC) No. 95/93 of 18 January 1993 on common rules for the allocation of slots at Community airports (as amended by Regulation No. 793/2004) (the Regulation).

Accordingly, in order to land or take off at Dublin airport, it is necessary for an air carrier or any other aircraft operator to have been allocated a slot by a coordinator, with the exception of State flights, emergency landings and humanitarian flights.

The Irish Aviation Authority (IAA) determines the parameters for slot allocation at Dublin airport and Airport Coordination Limited (ACL) carries out the allocation of slots.

On 29 August 2007, An Bord Pleanála granted development consent for a new Terminal 2 at Dublin airport, on condition that the combined capacity of Terminal 1 and Terminal 2 would not exceed 32 million passengers per annum unless authorised by a further grant of permission.

On 10 January 2008, development consent was also granted for the extension of Terminal 1, subject to the same condition.

In 2024, forecasts carried out by the Dublin Airport Authority (DAA) indicated that the limit of 32 million passengers per year could be reached or exceeded and, as such, the IAA published decisions on 7 May and 10 October 2024 setting seasonal passenger caps for flights to and from the airport.

The DAA and various air carriers brought proceedings before the High Court, resulting in a stay being granted on the seasonal cap set out in the 10 October decision and the referral of three questions to the European Court of Justice (ECJ) for preliminary ruling.

Questions for the ECJ

The first question concerned whether Article 6(1) of the Regulation is to be interpreted as meaning that conditions set out in development consents relating to the infrastructure of a coordinated airport and which require compliance with an annual passenger limit at that airport may constitute relevant technical, operational or environmental constraints of which account may be taken in the determination of the coordination parameters.

The second question queried whether, if the answer to the first question was yes, Article 6(1) of the Regulation and Articles 16 and 17 of the Charter of Fundamental Rights of the European Union allow Member States to determine the parameters for slot allocation at a coordinated airport for a particular scheduling period resulting in the non-allocation of some series of slots (or certain components thereof) to which air carriers would otherwise be entitled in accordance with the terms of Article 8(2) of the Regulation. 

The final question concerned whether the Regulation prohibits airport management bodies from taking unilateral action to close the airport for a period of time, for the purpose of preventing the operation of slots allocated by the airport coordinator so as to avoid a breach of an annual limit of passengers.

The European Court of Justice

In respect of the first question, the ECJ noted that neither the wording of Article 6(1) nor the definition set out in Article 2(m) of the Regulation expressly indicated whether development consents relating to airport infrastructure were capable of constituting technical, operational or environmental constraints or factors for the purposes of those provisions.

Nonetheless, the ECJ had regard to the broad wording of the provisions, deeming them capable of “encompassing all technical, operational and environmental constraints and factors, whatever they may be, irrespective of the reasons underlying them – whether political or otherwise – and regardless of whether they may be physical or legal in nature.”

Finding that what matters is whether or not a rule or measure affects the airport capacity of the airport concerned, and whether or not the operator of that airport is required to comply with it, the court determined that the issue of whether the passenger cap concerns the flow of passengers or the capacity of the airport is immaterial, where that condition sets a legally binding limit on the number of passengers which Dublin airport may accommodate.

Turning to the second question, the court explained that the validity of slots, including historic slots, is time-limited as they must be re-allocated at the end of specific scheduling period, either being returned to the slot pool or being re-allocated to the air carrier which used them in the previous scheduling period.

The court further outlined that having regard to the provisions of the Regulation, and in particular, to Article 8(3) thereof, slot allocation necessarily depends on there being sufficient availability of slots during the relevant scheduling period, which availability is governed by the coordination parameters determining the capacity of the airport.

The court opined that in light of the provisions of the Regulation and its general scheme, the EU legislature merely sought to ensure that, in the interest of operational stability at coordinated airports, air carriers satisfying certain conditions could be given priority over other operators in the allocation of slots, without conferring rights to maintain series of historic slots or to have them automatically renewed.

The court further observed that Recital 9 of the amending Regulation No. 793/2004 reflects the EU legislature’s objective of stability of operations, whilst respecting the airport capacity limits of a coordinated airport. 

Declining to interpret Article 16 of the Charter in the absence of reasons being given as to why interpretation thereof was necessary, the ECJ considered Article 17 of the Charter, noting that it was apparent from the relevant case-law that the protection afforded by Article 17 concerns rights with an asset value creating an established legal position and enabling the holder to exercise those rights autonomously and for their own benefit.

In light of the characteristics of slots, the ECJ was satisfied that the right conferred by Article 8(2) to request ‘historic’ slots cannot be treated as a ‘right to property’ within the meaning of Article 17 of the Charter, as the fact that it is a right which is “temporary and has not been definitively acquired…precludes the holder of historic slots from exercising rights with an asset value autonomously and for its own benefit in respect of such slots.”

Conclusion

Finding no necessity to answer the third question posed to it, the ECJ ruled in respect of the first question that Article 6(1) must be interpreted as meaning that conditions set out in development consents relating to the infrastructure of a coordinated airport and requiring compliance with an annual passenger limit at that airport may constitute relevant technical, operational or environmental constraints, within the meaning of that provision, of which account must be taken in the determination of the coordination parameters. 

As to the second question, the ECJ ruled that Article 6(1) must be interpreted as meaning that the determination of the parameters for slot allocation at a coordinated airport for a particular scheduling period, pursuant to that provision, may result in some series of slots or components thereof not being allocated to air carriers which would in principle be entitled to them under Article 8(2) of the Regulation.

DAA plc & Ors v Irish Aviation Authority & Anor, Case C 857/24, EU:C:2026:855