Joined Cases C-146/20, C-188/20, C-196/20 and C-270/20: Judgment of the Court (First Chamber) of 21 December 2021 (requests for a preliminary ruling from the Landgericht Düsseldorf, Landesgericht Korneuburg — Germany, Austria) — AD, BE, CF v Corendon Airlines (C-146/20), JG, LH, MI, NJ v OP, acting as liquidator of Azurair GmbH (C-188/20), Eurowings GmbH v flightright GmbH (C-196/20), AG, MG, HG v Austrian Airlines AG (C-270/20) (References for a preliminary ruling — Air transport — Regulation (EC) No 261/2004 — Common rules on compensation and assistance to passengers in the event of cancellation or long delay of flights — Articles 2 and 3 — Concepts of ‘operating air carrier’, ‘confirmed reservation’ and ‘scheduled time of arrival’ — Articles 5, 7 and 8 — Flight departure time brought forward in relation to the original planned departure time — Classification — Reduction in the amount of compensation — Offer of re-routing — Article 14 — Obligation to inform passengers of their rights — Scope)