The mission of the HCAA is to carry out certification, oversight and enforcement tasks in the field of air transport­, air navigation and airports­, to implement national and EU legislation and international conventions on charging and the operation of the Single European Sky (Regulation (EC) No 549/2004 of the European Parliament and of the Council of 10 March 2004 laying down the framework for the establishment of Single European Sky (L 96)), safety (as an indication­ Regulation (EU) 2018/1139 of the European Parliament and of the Council  of 4 July 2018 on common rules in the field of civil aviation and establishing  a ­European Union Aviation Safety Agency (L 212)), security (e.g. Regulation (EC) No 300/2008 of the European Parliament and of the Council of 11 March­2008 establishing rules in the field of civil aviation security and repealing Regulation (EC) No 2320/2002 (L 97)) and­ protecting  the  environment from civil aviation activities. The HCAA shall perform the functions of the­ regulatory authority for the economic activity of air transport, air navigation and airports, in accordance with Article 7.