"Extraordinary circumstances" is the airline's main defence against paying compensation, and also the most disputed. The Court of Justice of the EU has now decided dozens of cases. This guide groups them: events that count as extraordinary (so the airline may not have to pay), and events that do not (so you are likely owed compensation). Every point comes from the European Commission's official guidelines on the case law.
Last updated: 5 October 2026.
Under Article 5(3) of Regulation (EC) No 261/2004, an airline does not have to pay compensation for a cancellation or a long delay at arrival if it proves that the cause was an extraordinary circumstance that could not have been avoided even if all reasonable measures had been taken. It must prove both parts at once: the event and its link to your delay, and that it did everything reasonable to avoid the delay or cancellation.
The Court has developed two conditions that must both be met for an event to be "extraordinary":
Because this is an exception to the rule that passengers are compensated, the Court reads it strictly. Even the examples in the Regulation's recitals (political instability, weather, security risks, unexpected safety shortcomings, strikes) are not automatic: each case is judged on its facts. The Court also separates "internal" events (originating inside the airline's operation, which are not extraordinary) from "external" events (natural events or acts of third parties, which generally are).
| Event | What the Court decided | Case |
|---|---|---|
| Technical defect found at maintenance, or caused by poor maintenance | Not extraordinary. | C-549/07, Wallentin-Hermann |
| Unexpected breakdown of an aircraft part, even if maintenance was fine | Not extraordinary: breakdowns are inherent in running an airline, since "no component of an aircraft lasts forever". | C-257/14, van der Lans |
| Failure of a part that is only replaced when it becomes defective | Not extraordinary in principle. | C-832/18, Finnair |
| Collision with mobile boarding stairs | Not extraordinary: such equipment is indispensable to air transport. | C-394/14, Siewert |
| Unexpected illness or death of an essential crew member | Not extraordinary. | C-156/22 to C-158/22, TAP Portugal |
| Strike by the airline's own staff over pay or working conditions, including union-organised strikes | Not extraordinary. | C-28/20, Airhelp |
| "Wildcat" strike by airline staff after a surprise restructuring announcement | Not extraordinary. | C-195/17, Krüsemann |
| Strike by an airline's staff in solidarity with action at the parent company | Not extraordinary. | C-613/20, Eurowings |
| Strike measures to enforce workers' claims at the parent company | Not extraordinary, whether or not there were prior negotiations. | C-287/20, Ryanair |
On technical faults, the Commission's guidelines add that complying with the minimum maintenance rules does not by itself prove that the airline took all reasonable measures (Wallentin-Hermann). See also our guide on technical faults and compensation.
| Event | What the Court decided | Case |
|---|---|---|
| Hidden manufacturing defect disclosed by the manufacturer or an authority; sabotage or terrorism | Extraordinary, even if the manufacturer warned the airline months before the flight. | C-411/23 and C-385/23 (2024) |
| Bird strike (collision with a bird) | Extraordinary. It does not matter whether the aircraft was damaged. An emergency braking that damaged the tyres after an interrupted take-off was also covered. | C-315/15, Pešková; C-302/22, Freebird |
| Collision with another airline's aircraft; failure caused by a third party's catering vehicle | Extraordinary (or capable of being). | C-264/20, Airhelp; C-659/21, Orbest |
| Loose debris or a foreign object on the runway damaging the aircraft | Extraordinary. | C-501/17, Germanwings |
| Petrol on the runway closing the airport, if it did not come from the airline's own aircraft | Extraordinary. | C-159/18, Moens |
| General breakdown of the airport's refuelling system | Can be extraordinary, if the origin airport is responsible for it. | C-308/21, SATA |
| Unruly passenger causing a diversion; removal of a passenger for a medical emergency | Extraordinary, unless the airline contributed to the behaviour or ignored warning signs. | C-74/19, Transportes Aéreos Portugueses |
| Volcanic eruption closing airspace (Eyjafjallajökull) | Extraordinary. | C-12/11, McDonagh |
| Bad weather causing airport congestion and capacity shortages | Extraordinary, according to recital 14 of the Regulation. | Regulation recital 14 |
| Strike by air traffic controllers or airport staff | May be extraordinary, because it is external to the airline. | C-28/20, Airhelp |
| Strike over demands only public authorities can satisfy | Capable of being extraordinary. | C-28/20, Airhelp |
| Shortage of the airport operator's baggage-loading staff | May be extraordinary. | C-405/23, Touristic Aviation Services |
Proving an extraordinary event is not enough. The airline must also show that it deployed all its staff, equipment and financial means to avoid the delay or cancellation, although it cannot be asked to make intolerable sacrifices given its capacity at the time. Some points from the guidelines:
Extraordinary circumstances only remove the right to compensation (the fixed 250, 400 or 600 euros). The airline must still offer care (meals, hotel, transport) and a choice between refund and rerouting. The Court has stressed that there is no separate category of "particularly extraordinary" events that would excuse the airline from all its obligations (C-12/11, McDonagh). See our guide on meals, hotel and expenses during a delay.
No. Weather "incompatible with the operation of the flight" can be, and recital 14 and the guidelines mention congestion at an airport due to bad weather. But the airline still has to prove that the weather actually caused your delay and that it took all reasonable measures.
It depends on whose strike it is. A strike by the airline's own staff over pay or restructuring is not. A strike by air traffic controllers or airport staff may be. See our guide on strikes.
The airline. It has to prove the event, the link to your delay and the reasonable measures. The Commission's view is that it should provide its evidence, such as logbook extracts or incident reports, free of charge to you and to the national enforcement body.
This guide is general information based on the sources above, not legal advice. Each case is judged on its own facts, and new rulings can change the picture.
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