Judgment of the Court (Ninth Chamber) of 6 October 2021.#CS v Eurowings GmbH.#Request for a preliminary ruling from the Landesgericht Salzburg.#Reference for a preliminary ruling – Air transport – Regulation (EC) No 261/2004 – Article 5(3) – Common rules on compensation and assistance to passengers in the event of cancellation or long delay of flights – Exemption from the obligation to pay compensation – Concept of ‘extraordinary circumstances’ – Strike by airline staff – Strike by the staff of a subsidiary in solidarity with the staff of the parent company.#Case C-613/20.