Judgment of the General Court (Sixth Chamber) of 21 December 2021.#Gmina Miasto Gdynia and Port Lotniczy Gdynia-Kosakowo sp. z o.o. 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 – Withdrawal of a decision – Failure to re-open the formal investigation procedure – Procedural rights of the interested parties – Rights of the defence – Obligation to state reasons.#Case T-263/15 RENV.