Extraordinary circumstances: what airlines can and cannot invoke

This is the #1 argument airlines use to refuse EC 261 compensation: "extraordinary circumstances". In reality, 80% of these invocations are contestable — either because they don't meet the legal criteria, or because the airline cannot prove them. Here's the complete guide, grounded in CJEU case law.

What counts as an extraordinary circumstance under EC 261?

Article 5(3) of EC 261 provides that the airline is exempt if it proves the delay/cancellation was due to extraordinary circumstances which could not have been avoided even if all reasonable measures had been taken.

The CJEU has clarified two cumulative criteria:

1. Externality: the event is outside the airline's control (not a risk inherent to its activity)
2. Unavoidability: even with all reasonable measures, the delay could not have been avoided

Landmark case: CJEU, Wallentin-Hermann v Alitalia, 22 December 2008 (C-549/07) — sets the foundation. Followed by dozens of rulings refining each concrete case.

Table: what counts and what doesn't

Technical failure: the most common and misunderstood case

It's the most frequently cited justification. Airlines write "technical issue" and assume that's enough. It isn't.

The CJEU established that technical failures resulting from the normal or abnormal maintenance of an aircraft are NOT extraordinary circumstances, because they are inherent to the operation of an aircraft. Maintenance is the airline's responsibility.

Narrow exception: a hidden manufacturing defect, not detectable during regulatory inspections, communicated by the manufacturer only on the same day (e.g. emergency airworthiness bulletin) may constitute an extraordinary circumstance. This is extremely rare and the airline must provide documentary proof.

Weather: the line between unforeseeable and negligence

Not all weather events are equal:

• Sudden tropical storm over Dakar one August evening → potentially extraordinary if the previous day's weather data didn't predict it
• Harmattan sand haze in January over West Africa → foreseeable (well-known seasonal phenomenon). The airline must plan accordingly
• Ice on the CDG runway in November → foreseeable, ground handling = airport and airline responsibility

Strikes: an essential distinction

Since the CJEU ruling of 17 April 2018 (Krüsemann v TUIfly), internal airline staff strikes are no longer extraordinary circumstances — they are a risk inherent to staff management.

However:

• Air traffic controllers' strike → extraordinary ✔
• Airport ground handler strike (external provider) → may be extraordinary depending on context
• Customs officers' strike → extraordinary if unforeseeable ✔

How to contest an "extraordinary circumstances" refusal

The burden of proof lies with the airline, not you. They must prove:

1. The exact nature of the extraordinary circumstances (official technical report, weather NOTAM, ATC decision…)
2. That these circumstances were unforeseeable
3. That all reasonable measures were taken to avoid the delay (replacement aircraft, rerouting…)

Request these proofs in writing in your claim. Without supporting documents, courts almost always rule for the passenger.

Our experience: on Robin des Airs files, 4 out of 5 "extraordinary circumstances" refusals are successfully contested. Airlines know most passengers will give up after a refusal — that's their strategy.

Related: Airline refuses your claim: next steps, Complete EC 261/2004 summary.