Opinion of Advocate General Ćapeta delivered on 7 April 2022.#Volotea, SA and easyJet Airline Company Ltd. v European Commission.#Appeal – State aid – Article 107(1) TFEU – European Commission decision on compensation to Sardinian airports for public service obligations – Existence of unlawful State aid incompatible with the internal market, granted by the Italian Republic to airlines through airport operators – Concept of ‘State aid’ – Proof of the existence of an advantage – Determination of the amount – Market economy operator principle – Applicability and application – Test of the private acquirer of goods or services – Conditions – Burden of proof.#Joined Cases C-331/20 P and C-343/20 P.