EU261 flight delay claims: When airline choices break the causal chain

Case T‑656/24 - NI, HZ v European Air Charter AG, General Court, 4 March 2026

Background

NI and HZ were passengers on a Düsseldorf–Varna flight scheduled for 23 July 2022. The flight was to be the third rotation of the aircraft. Earlier that morning, at Cologne–Bonn Airport, a generalised failure of the airport security checkpoint caused all passengers on the first rotation flight to be significantly delayed in presenting themselves for boarding.

The carrier chose to wait for those delayed passengers. That first flight took off, with a delay of some five hours. Having regard to the delay of the first flight rotation, the carrier re-arranged the day's operations by chartering another aircraft to operate the second and third rotations. Despite these efforts, the claimant passengers (travelling on the third flight) arrived in Varna more than three hours late, triggering claims against the carrier for EU261 flight delay compensation.

Their claims for EUR 400 each under EU261 were rejected by the court in Düsseldorf at first instance. On appeal, the Regional Court accepted that the sudden and considerable shortage of security staff, in principle, could constitute an extraordinary circumstance, but questioned whether the requisite direct causal link existed given that the carrier had voluntarily opted to wait for delayed passengers. The German court referred two questions to the General Court for a preliminary ruling, namely (i) whether the delay concerned could still be attributed to the 'extraordinary circumstances' when the carrier voluntarily chose to wait for passengers on the first flight, and (ii) whether the number of such passengers was relevant to determining when the carrier’s own actions became the determining cause of the flight delay. 

Decision

In its ruling of 4 March 2026, and as concerns the first question, the General Court found as follows:

• Carriers may rely on an extraordinary circumstance affecting an earlier flight only if there is a direct causal link with the delay of the subsequent flight at issue in the claim (following Austrian Airlines, C‑826/19).

• The mere fact that conduct constituted a necessary condition (a sine qua non) for the damage to occur, in the sense that the damage (i.e. the delay) would not have occurred without that conduct, is not sufficient to establish a sufficiently direct causal link.

• The condition relating to the causal link requires that that link must be sufficiently direct, so that the conduct complained of (here, the security delays) must be the determining cause of the damage (the delay that is the basis of the claim).

• The causal link may be broken, inter alia, by an act which arises between the conduct complained of and the damage alleged, where that act constitutes the determining cause of that damage. Such an act may consist, inter alia, of a decision, provided, however, that the person taking the decision was not obliged to do so.

Applying this reasoning to the facts, the court concluded, "it follows that that decision taken by the air carrier to wait for the passengers of the first flight arose between the occurrence of the extraordinary circumstance and the delay of the flight at issue in the main proceedings. That decision is capable of breaking the direct causal link between those two events if it constitutes the determining cause for the delay of the flight at issue in the main proceedings and provided that the air carrier was not obliged to take that decision, in particular under a legal obligation, which it is for the referring court to ascertain." In view of the answer to the first question, the court concluded that there was no need to answer the second question.

Ironically then, had the carrier refrained from intervening (i.e., had simply allowed the flight rotations to run their delayed course and had not substituted the aircraft), the EU261 'extraordinary circumstances' defence would, in all likelihood, have remained available.

Felix qui potuit rerum cognoscere causas

The General Court's reasoning followed the opinion of Advocate General, Martín y Pérez de Nanclares, delivered on 26 November 2025. That opinion is noteworthy, not least because it opens, unusually, with a line from Virgil's Giorgics, Book II, ‘Felix qui potuit rerum cognoscere causas’ : Happy is he who has been able to know the causes of things. This is a most fitting preface for an opinion centred on causation. 

Before the Advocate General, both the carrier and the commission, in written and oral submissions, highlighted the unhappy predicament in which the carrier found itself:

"What, indeed, should European Air Charter have done? Abandon the passengers of the first flight or some of them, and fly empty or almost empty, to ensure that the flight at issue in the main proceedings was operated with a delay of less than three hours?"

Whilst acknowledging this operational dilemma, the Advocate General declined to allow this reasoning to influence the causation analysis:

“However reasonable that question may be, I do not believe that it should be taken into consideration in the analysis of the causal link, simply because that issue seems to me to be unrelated to Regulation No 261/2004.”

He went on:

“Permitting an air carrier to rely on a balancing of the interests of different groups of passengers… would be tantamount to adding an exemption clause to the obligation to compensate laid down in Article 5(3)… [i]t is clear that such flights are not an optimal solution, in particular from an environmental perspective, just as it is clear that Regulation No 261/2004 cannot be interpreted as requiring air carriers to operate empty flights in order to ensure that passengers arrive at their destination with less than three hours’ delay. However, it is not possible to infer what is not stated in the wording of the provision. The aim of avoiding an empty flight does not constitute an exemption from the obligation to pay compensation laid down in Article 5(3) of Regulation No 261/2004."

What this decision means for carriers

The decision of the General Court reinforces a strict interpretation of Article 5(3) of EU261:

• The practical message is clear: a carrier's operational discretion can break the causal chain. Once the carrier chooses a course of action that becomes the effective cause of a later delay, the protective shield of the Article 5(3) 'extraordinary circumstances' defence may fall away. Airlines must carefully assess their response to flight disruptions, recognising that well‑intentioned decisions—such as waiting for passengers—may expose them to claim liability on subsequent flight rotations.
• The judgment of the General Court was delivered on 4 March 2026. It is final, (i) if it is not appealed within two months or (ii) if an appeal is not granted or (ii) if (on appeal) the ECJ affirms it. Appeals are limited to points of law and not the re-evaluation of the facts.

Coming up

In the next instalments of this series, we will review further 2026 CJEU decisions shaping EU261 jurisprudence: Case C‑45/24 — Verein für Konsumenteninformation v Koninklijke Luchtvaart Maatschappij NV and Case T‑134/25 — D S.A. v P S.A.

[1] The UK, following Brexit, retains the core principles of EU261 within the domestic regime (UK261). Although post‑Brexit CJEU decisions no longer bind UK courts, they continue to hold persuasive authority in domestic adjudication.