Air transport: Single European Sky

The Single European Sky initiative aims to increase the efficiency of air traffic management and air navigation services by reducing the fragmentation of European airspace. This is a pan-European initiative open to neighbouring countries.

Legal basis

Article 100(2) of the Treaty on the Functioning of the European Union.


The Single European Sky (SES) initiative was launched in 1999 to improve the performance of air traffic management (ATM[1]) and air navigation services (ANS[2]) through better integration of European airspace. The stated benefits of the SES could potentially be huge: compared to 2004, the SES (upon completion around 2030-2035) could triple airspace capacity, halve the costs of ATM, improve safety tenfold and reduce the environmental impact of aviation by 10%[3].


The SES initiative was launched in response to delays resulting from air navigation, with the intention of reducing the fragmentation of European airspace (between Member States, civil and military usage, and technologies), thereby increasing its capacity and the efficiency of ATM and ANS. The initiative is pan-European and open to neighbouring countries. In practice, the SES should result in reduced flight times (because of shorter paths and fewer delays) and, consequently, in lower flight costs and aircraft emissions. The first set of common requirements establishing the SES was adopted in 2004 (SES I). These included Regulation (EC) No 549/2004 laying down the framework for the creation of the Single European Sky, Regulation (EC) No 550/2004 on the provision of air navigation services, Regulation (EC) No 551/2004 on the organisation and use of the airspace in the Single European Sky[4], and Regulation (EC) No 552/2004 on the interoperability of the European Air Traffic Management network. This framework was amended in 2009 (SES II) to include performance-based mechanisms (Regulation (EC) No 1070/2009). It was also complemented by the extension of EU rules on aviation safety (and the related competences of the European Aviation Safety Agency to include ATM and ANS) and on airport operations[5]. In parallel, a number of implementing rules and technical standards have been adopted either by the Commission through the comitology procedure or, less frequently, by the legislator[6].

This comprehensive regulatory framework has boosted the restructuring of European airspace and the provision of ANS, by introducing the separation of regulatory functions from service provision, much greater flexibility in the civil and military use of airspace, the interoperability of equipment, the harmonised classification of upper airspace[7], a common charging scheme for ANS and common licensing requirements for air traffic controllers. In addition, it has established the ‘key components’, which form the structure of the SES:

  • Under the ‘performance scheme’[8], binding performance targets in key areas – such as safety[9], the environment, capacity, cost efficiency and incentives – are set in order to improve the overall efficiency of ATM and ANS. The performance targets are adopted by the Commission through the comitology procedure[10]. The ‘performance review body’ appointed by the Commission helps in the preparation of these targets and monitors the implementation of the performance scheme;
  • The role of the ‘network manager’ (currently Eurocontrol[11]) is to improve the performance of the EU aviation network. It deals with the network functions, which must be handled in a centralised manner, as is the case with the design of the European route network, air traffic flow management (ATFM) and the coordination of radio frequencies used by general air traffic;
  • ‘Functional airspace blocks’ (FABs) are intended to remedy the fragmentation of European airspace by restructuring it according to traffic flows rather than national boundaries. This is to permit enhanced cooperation (i.e. better management of airspace, optimisation of the route network and an economy of scale through the integration of services) or even mergers between service providers across national borders, thereby lowering the costs of ANS.
  • The SESAR (Single European Sky ATM Research) Joint Undertaking, set up in 2007, manages the technological and industrial dimension of the SES, i.e. the development and deployment of the new European ATM system, and aims to increase the levels of automation, secure data sharing and connectivity in ATM as part of its Digital European Sky initiative.

However, the full integration of the European airspace is still far from complete. The SES initiative (which in any case was not expected to be completed by 2030-2035) faced difficulties and resistance, in particular because of its huge scope. In June 2013, the Commission proposed a new set of rules to address the issues of efficiency and performance, as well as the present suboptimal institutional set-up. However, despite Parliament adopting its first reading position in 2014, discussions on those measures with the Council stalled soon after.

On 22 September 2020, the Commission adopted a revised version of the same proposal with a view to providing more sustainable and resilient ATM in line with the European Green Deal. The proposed upgrade consists of an amended proposal for a regulation on the implementation of the SES (2013/0186(COD)), including in particular the removal of the provisions on the mandatory use of FABs and a proposal to amend Regulation (EU) 2018/1139 as regards the capacity of the European Union Aviation Safety Agency to act as performance review body of the SES (2020/0264(COD))[12]. In June 2021, the Committee on Transport and Tourism adopted its report on the latter proposal and also adopted its updated negotiating mandate for the proposal for a regulation on the implementation of the SES (2013/0186(COD)). In October 2019, the Committee on Transport and Tourism decided to enter into interinstitutional negotiations with the Council.

On 5 March 2024, Parliament and the Council reached a provisional agreement on the reform of the Single European Sky, which needs to be formally approved by both institutions. The key elements of the provisional agreement are that:

  • Air navigation service providers and the national supervisory authority can be part of the same organisation provided they are functionally separated and meet independence requirements;
  • Member States will have the possibility to merge economic and safety oversight functions in the same administrative entity;
  • The opening of certain air navigation services to market conditions may be authorised by Member States;
  • A cost-benefit analysis will look at the issue of mandatory modulation of en route charges to encourage airspace users to support improvements in climate and environmental performance;
  • National supervisory authorities and the Commission will together assess the performance of air navigation services, and an independent advisory performance review board (PRB), within the Commission, will be set up to assist in this task;
  • To align the two separate procedures (SES2+, 2013/0186(COD)) in its second reading and EASA-PRB (2020/0264(COD) in its first reading), the legislator decided to merge both Commission proposals into one and therefore, the provisions on PRB became part of the revision of the SES2+.

The provisional agreement was approved by the Committee on Transport and Tourism on 9 April 2024 and, pending the adoption of the Council’s first reading position, will be put to a vote in plenary.

In April 2020, the Commission amended Implementing Regulation (EU) No 1206/2011 laying down requirements on aircraft identification for the surveillance of the Single European Sky. It also amended Implementing Regulation (EU) No 1207/2011 laying down requirements for the performance and the interoperability for the surveillance of the Single European Sky (Implementing Regulation (EU) 2020/587). The revision of both implementing regulations includes improvements to the operating rules related to the use of airspace, aircraft equipment and ATM and ANS.

Role of the European Parliament

Parliament has always endeavoured to remove obstacles to the implementation of the SES by adopting a pragmatic approach. In this context, it has insisted strongly and successfully on the need for close cooperation between the civil and military sectors as regards the flexible use of airspace. Parliament also proposed the creation of an industry consultation body to enable stakeholders to advise the Commission on technical aspects of the SES. In addition, Parliament has always emphasised the crucial role that Eurocontrol has to play in the implementation of the SES and the need to foster cooperation with neighbouring countries with a view to extending the initiative beyond EU borders. Moreover, Parliament stresses the need to ensure that the SES follows the Green Deal objective of reducing the environmental impact of the aviation industry.

Given that the major objectives of the SES are yet to be achieved, Parliament is now calling on the Commission to switch from a ‘bottom-up’ to a ‘top-down’ approach in order to overcome any lingering reticence and to speed up the implementation of the initiative, in particular with respect to the SESAR programme.

Major related decisions made by Parliament include:

For more information on this topic, please see the website of the Committee on Transport and Tourism.


[1]Air traffic management (ATM) ensures the safe and efficient movement of aircraft during all phases of operations (including air traffic services, airspace management and air traffic flow management).
[2]Air navigation services (ANS) are all the services provided to air navigation, including air traffic services, communication, navigation and surveillance services, meteorological services and aeronautical information services.
[3]These are the ‘official’ SES objectives, the origin of which is unclear.
[4]From airport to airport, as airports serve as entry and exit points to airspace. This is referred to as the ‘gate to gate’ approach.
[6]As is the case with Directive 2006/23/EC on a Community air traffic controller licence.
[7]Airspace is classified in accordance with ‘classes’ defined by the Chicago Convention on International Civil Aviation, which are given a designation ranging from ‘Class A’ to ‘Class G’. Flight rules and the services provided differ from one class to another.
[9]As of 2015.
[10]The first reference period for the performance scheme covered the calendar years 2012 to 2014. From 2015 onwards, each reference period covers five calendar years.
[11]The European Organisation for the Safety of Air Navigation (Eurocontrol) is a pan-European civil-military intergovernmental organisation created in 1963 for the purpose of maintaining safety in the field of air traffic management. Eurocontrol is made up of 41 contracting states. There is a cooperation agreement between Eurocontrol and the EU to implement the SES. In 2011, the Commission designated Eurocontrol as the first ‘network manager’ of the SES until the end of 2019 and from 1 January 2020 to 31 December 2029 by Commission Implementing Decision (EU) 2019/709. Eurocontrol was also nominated as the first SES ‘performance review body’ over the 2010-2016 period.
[12]Considering that a provisional agreement was reached on 5 March 2024, Commission proposal COM(2020)0577 is expected to be withdrawn by the Commission.

Ariane Debyser / OLENA KUZHYM