Federal Office of Civil Aviation, ICAO Action Plan on CO2 Emission Reduction of Switzerland, 2021-06, p. 5, para. I, let. e ([Internet, 2023-01-10](https://www.google.com/url?sa=t&rct=j&q=&esrc=s&source=web&cd=&ved=2ahUKEwiTu7Po5Lz8AhWuiP0HHeztB-IQFnoECAkQAQ&url=https%3A%2F%2Fwww.bazl.admin.ch%2Fdam%2Fbazl%2Ffr%2Fdokumente%2FFachleute%2FRegulationen_und_Grundlagen%2FUmwelt%2FICAO%2520Action%2520Plan%2520on%2520CO2%2520emission%2520reduction%2520of%2520Switzerland_Update%2520August%25202018.pdf.download.pdf%2FICAO%2520Action%2520Plan%2520on%2520CO2%2520emission%2520reduction%2520of%2520Switzerland_Update%2520August%25202018.pdf&usg=AOvVaw0ZsbcyElZBjcjX0Jd7Y1NQ))