Extraordinary Circumstances: When Airlines Can Refuse Compensation

"Extraordinary circumstances" is the phrase airlines use most often to reject compensation claims. Sometimes they are right. Often they are not. The phrase has a specific legal meaning that the Court of Justice of the EU has developed over two decades, and knowing the main rulings lets you judge whether a refusal holds up.

The legal test

Article 5(3) of Regulation 261/2004 says an airline does not have to pay compensation for a cancellation if it can prove the cancellation was caused by extraordinary circumstances which could not have been avoided even if all reasonable measures had been taken. The Court applies the same defence to long delays. Three points follow from the wording:

• The burden of proof is on the airline, not on you.
• The event must be outside the normal exercise of the airline's activity and beyond its actual control.
• Even if the event qualifies, the airline must show it took all reasonable measures to avoid the cancellation or delay — for example by having reasonable reserve time or capacity.

Recital 14 gives examples: political instability, meteorological conditions incompatible with the flight, security risks, unexpected flight safety shortcomings and strikes affecting the operation of the airline.

Technical problems

The most important case is Wallentin-Hermann (C-549/07), decided in 2008. An Alitalia flight was cancelled because of a complex engine defect discovered during a check. The Court held that a technical problem is not an extraordinary circumstance unless it stems from events which, by their nature or origin, are not inherent in the normal exercise of the airline's activity and are beyond its control. Aircraft break; maintaining them is part of running an airline. So routine faults, even unexpected ones, generally do not let the airline off.

Later rulings carved out narrow exceptions: hidden manufacturing defects revealed by the manufacturer or authorities, and damage caused by sabotage or terrorism. A spontaneous failure of a component that was properly maintained is still generally not extraordinary.

Bird strikes and foreign objects

In Pešková (C-315/15), the Court held that a collision with a bird is an extraordinary circumstance, because it is not intrinsically linked to the operation of the aircraft. But the airline still had to show that the long delay was caused by the bird strike and could not have been avoided by reasonable measures — for example, the extra delay caused by waiting for a particular expert to inspect the aircraft may not be justified. Debris on the runway has been treated similarly.

Weather

Severe weather that makes a flight unsafe — thunderstorms, heavy snow, fog below landing minimums, volcanic ash — usually qualifies. What matters is the weather affecting your flight, not general claims of "bad weather in Europe". If other airlines flew the same route on time, or the weather affected a different airport earlier in the aircraft's day, ask for details. Airlines should be able to show records such as airport closures or ATC restrictions.

Air traffic control and airport problems

Decisions by air traffic control to restrict capacity, airport closures and failures of airport fuel systems are generally outside the airline's control. Strikes by air traffic controllers or airport staff count as extraordinary because the airline cannot influence them.

Strikes by the airline's own staff

Strikes are where the law has moved most. In Krüsemann (C-195/17), many TUIfly crew members reported sick at the same time after a surprise restructuring announcement — a "wildcat strike". The Court held this was not extraordinary, because it arose from the airline's own management decisions and was part of normal business risk. In a 2021 ruling (C-28/20, Airhelp v SAS), the Court went further: a strike called by a trade union of the airline's own staff to obtain pay increases is not extraordinary either. So most strikes by pilots or cabin crew of the operating airline do not excuse it. Strikes by third parties — air traffic controllers, airport security, ground handlers employed by other firms — usually do.

Knock-on delays

Airlines often operate an aircraft on several flights a day. If an earlier flight was hit by an extraordinary circumstance and that delay carried through to your flight, the airline can rely on the earlier event — but only if there is a direct causal link and it took reasonable measures to limit the knock-on effect. A generic "late arrival of the incoming aircraft" explanation is not enough by itself.

Crew shortages and illness

Staff shortages, crew running out of permitted duty hours and individual crew illness are generally risks inherent in operating an airline, so they are not extraordinary. The Court has held that the sudden death of a co-pilot shortly before departure was not extraordinary either, because ensuring crew availability is part of normal activity.

Medical emergencies and disruptive passengers

A diversion because a passenger needs urgent medical help is generally accepted as extraordinary. The Court has also held that disruptive passenger behaviour justifying a diversion can be extraordinary, unless the airline contributed to it — for example by boarding a passenger who already showed signs of disruptive behaviour.

What to do when an airline cites extraordinary circumstances

1. Ask in writing what exactly happened and when. A vague answer is a weak answer.
2. Check publicly available information: airport notices, ATC announcements, news reports, whether other flights operated.
3. Ask what reasonable measures the airline took — reserve aircraft, rebooking on other carriers.
4. If you remain unconvinced, escalate to the ADR scheme, national enforcement body or court. These bodies regularly ask airlines for evidence.

Remember that even when compensation is excluded, care (food, hotel) and the choice of refund or re-routing still apply.

Quick reference

Cause	Usually extraordinary?
Severe weather at the airport	Yes
ATC restrictions or ATC strike	Yes
Airport security alert	Yes
Bird strike	Yes (if delay not prolonged unreasonably)
Routine technical fault	No
Strike by the airline's own crew	Generally no
Crew shortage or illness	No
Late incoming aircraft due to an earlier technical fault	No

This table summarises general tendencies, not guaranteed outcomes. Each case turns on its facts.