95In so far as the Commission argued at the hearing before the Court of Justice that no ‘decision’ specifically imposing on the two aircraft a flight ban as laid down in Article 3d of Regulation No 833/2014 had been adopted by its College of Commissioners, suffice it to recall that, in accordance with settled case-law, the fact that an act does not take the form of a formal Commission decision is not decisive for its classification as an act open to challenge for the purposes of Article 263 TFEU (see, to that effect, judgments of 11 November 1981, IBM v Commission, 60/81, EU:C:1981:264, paragraph 9, and of 17 July 2008, Athinaïki Techniki v Commission, C‑521/06 P, EU:C:2008:422, paragraphs 44 and 59).