for Europe (A4E), AIRE, ACI Europe, CANSO, ERA and IATA, signed an agreement in Brussels to urge the creation of an SES, and to work together with EU institutions and member states to achieve it. The Commission appointed 15 experts in the field to form a Wise Person's Group to assess the current situation and future needs. After Brexit was formally completed on 31 January 2020 (eliminating UK objections and the Gibraltar issue), and the COVID-19 pandemic put the aviation sector into an existential crisis, the European Commission made a new proposal for a Single European Sky on 22 September 2020. It used the expert group's recommendations to amend the 2013 proposal's text, and introduced new measures; separately, it also drafted a proposal to amend the EASA Basic Regulation. Instead of relying on top-down regulation, which appeared not to have worked previously, the Commission stimulated voluntary alliances between so-called air traffic service providers. Airlines for Europe supported the proposal, but stressed the importance of 'enhanced governance structure' to ensure its success. Meanwhile, the FABEC and FAB CE zones, jointly accounting for 8.6 million flights (over 75% of all European air traffic) in 2019, agreed to formalise and intensify their cooperation in June 2020. Timeline Late 1999: European Commission appoints expert group to study the creation of a single European sky. November 2000: expert group publishes report with recommendations. 11 December 2003: SES-I (Regulation (EC) No 550/2004 alias Service Provision Regulation) adopted. 20 April 2004: SES-I in force. 21 October 2009: SES-II regulation adopted. 4 December 2009: SES-II regulation in force. June 2013: SES 2+ proposed. September 2020: Amended SES 2+ proposed. See also Air travel disruption after the 2010 Eyjafjallajökull eruption European Common Aviation Area Eurocontrol European Neighbourhood Policy Kerosene tax Short-haul flight ban Single European Sky ATM Research (SESAR) South-East Europe Regional Energy Market Stability Pact for South Eastern Europe References Further reading Single European Sky (SES) The European ATM Master plan External links Single European Sky – European Commission website Single European Sky – EUROCONTROL website Single European Sky – Performance Scheme Indicator meta-data Airports Council International EUROPE website Construction of the Single European Sky Implementing Rules for the Single European Sky Multilateral Agreement on the establishment of a European Common Aviation Area The Commission launches Single European Sky II for safer, greener and more punctual flying Clean Sky Transport and the European Union Air traffic control in