Functional Airspace Block (FAB) means an airspace block based on operational requirements and established regardless of State boundaries, where the provision of air navigation services and related functions are performance-driven and optimized with a view to introducing, in each functional airspace block, enhanced cooperation among air navigation service providers or, where appropriate, an integrated provider. (SES Framework Regulation)
The Single European Sky Service Provision Regulation requires that by 4 December 2012, Member States shall take all necessary measures in order to ensure the implementation of functional airspace blocks with a view to achieving the required capacity and efficiency of the air traffic management network within the Single European Sky and maintaining a high level of safety and contributing to the overall performance of the air transport system and a reduced environmental impact.
The requirements for the establishment of Functional Airspace Blocks (FAB) are defined in the EUROCONTROL Report on the European Commission’s Mandate on the subject. It identifies improvements in flight-efficiency within each FAB which provides significant opportunities for savings to operators and benefits for the environment. According to EUROCONTROL, one quarter of European route extension issues can only be solved across FABs and Europe-wide, a strong and effective network management and design function at European level is necessary.