Despite the regulatory efforts, fragmentation of European Union Airspace is still a matter along with the increase of traffic and emerging necessities like environmental sustainability, innovation. In 2020, the Commission proposed an upgrade of the Single European Sky (SES) regulatory frameworkin the light of recent developments. The proposal no longer contained provisions on the use of FABs and among other things it introduced the possibility of common unit rate for en route services across the SES airspace. On the same time and in 2021 as part of the ‘Fit for 55 package’, the Commission proposed amendments to the EU ETS Directive 2003/87/EC as regards aviation's contribution to the EU emission reduction target. All these proposals are on discussion before the EU Parliament and Council but beyond this, the forecast related to air traffic growth, innovation and digitalization, strikes, war crisis and meteorological events will put pressure to the current European airspace management. The aim of this paper is to analyze the current legal framework and proposals related to SES and Aviation Sustainability in the lights of evolutions, highlighting strengths and weakness in consideration of goals and on-going negotiations aiming to support the reaching of the Green Single European Sky.