Judgment of the General Court (Sixth Chamber) of 21 December 2021.#Gmina Kosakowo v European Commission.#State aid – Airport infrastructure – Public funding by the municipalities of Gdynia and Kosakowo for setting up the Gdynia-Kosakowo Airport – Decision declaring the aid incompatible with the internal market and ordering its recovery – Advantage – Market economy operator principle – Effect on trade between Member States – Adverse effect on competition – Recovery – Obligation to state reasons.#Case T-209/15.