On 13 June 2024, the Court of Justice handed down its judgment in Case C-411/23, D. S.A. v P. S.A., on the interpretation of Article 5(3) of Regulation (EC) No 261/2004. The request has been made in proceedings between D. S.A.(“D”), the assignee of the rights of J.D., and P. S.A. (“P”) regarding its refusal to pay compensation to the latter, a passenger whose flight was subject to a long delay in arrival.

On 2 July 2018, J.D. entered into a contract of air carriage with P concerning a flight from Cracow to Chicago. Previously, however, the manufacturer of the engine fitted to the aircraft scheduled to operate that flight disclosed to the latter the existence of a hidden design defect imposing a number of restrictions on the use of those aircraft.  After that date, therefore, P contacted various carriers on several occasions with a view to chartering additional aircraft to pre-empt the possibility of an engine design defect being discovered in any of the aircraft in its fleet. Four days before the scheduled flight, an engine malfunction occurred during a flight operated by the aircraft supposed to carry J.D. on the flight he had booked. After consulting the engine manufacturer, therefore, P took out of service, disassembled and sent to a maintenance centre the engine concerned. Since there were no immediately available spare engines due to a global engine shortage, however, it was not possible to replace the defective one until 5 July 2018, so that the aircraft was brought back into service on 7 July 2018.

Against that background, P operated the flight scheduled for 2 July 2018 with a replacement aircraft which arrived more than three hours after the originally scheduled time. Following P’s refusal to pay compensation according to Regulation No 261/2004, D brought an action before the Sąd Rejonowy dla m. st. Warszawy w Warszawie (District Court, Warsaw), which however refused it. Therefore, D brought an appeal before the Sąd Okręgowy w Warszawie (Regional Court of Warsaw; the “referring court”) which, in light of the need to interpret the relevant European legislation, decided to stay the proceedings and to refer to the Court of Justice two questions for a preliminary ruling.

By the first question, the referring court asked whether Article 5(3) of Regulation No 261/2004 must be interpreted as meaning that the detection of a hidden defect in the design of the engine of an aircraft which is to operate a flight is covered by the concept of “extraordinary circumstances” within the meaning of that provision, even where the engine manufacturer had informed the air carrier of its existence several months before the flight concerned.

According to the Court, the classification of a hidden design defect as an “extraordinary circumstance” is not subject to the condition that the aircraft manufacturer, the engine manufacturer or the competent authority must have revealed its existence before the technical failure caused by that defect occurred. The point in time at which the link between the technical failure and the hidden design defect is revealed by the aircraft manufacturer, the engine manufacturer or the competent authority, indeed, is irrelevant since the latter existed at the time of the cancellation or long delay of the flight and the carrier had no means of control to correct it.

By the second question, instead, the referring court asked whether Article 5(3) of Regulation No 261/2004 must be interpreted as meaning that an air carrier must, as part of “all the reasonable measures” which it is required to take in order to prevent the occurrence and the consequences of an “extraordinary circumstance” within the meaning of that provision, such as the detection of a hidden defect in the design of the engine of one of its aircraft, adopt a preventive measure consisting of having a back-up fleet of aircraft on standby.

According to the Court, Article 5(3) of Regulation No 261/2004 does not require air carriers, in a general and indiscriminate manner, to adopt, as part of the “reasonable measures”, a given preventive one, such as having a back-up fleet of aircraft and the corresponding crew on standby, where it has been informed of the existence of an engine design defect revealed by the engine manufacturer, in order to prevent extraordinary circumstances from arising and the consequences thereof.

Marco Stillo