What are extraordinary circumstances in flight compensation?

Extraordinary circumstances are events that could not have been avoided even if all reasonable measures had been taken. They exempt an airline from paying UK261 compensation. They include: severe and unusual weather, air traffic control strikes, political instability, security threats, and hidden manufacturing defects that could not have been detected. Crucially, the airline must prove: (1) that extraordinary circumstances existed; (2) that the delay was caused by those circumstances; and (3) that they took all reasonable measures to avoid the delay.

Are technical faults extraordinary circumstances?

Generally no. The European Court of Justice ruled in Wallentin-Hermann v Alitalia [2008] that a technical problem discovered during the pre-flight check does not constitute extraordinary circumstances unless it stems from a hidden manufacturing defect that could not be detected in advance. Routine maintenance issues, aging aircraft problems, or pre-existing technical faults are the airline's operational responsibility and do not qualify as extraordinary.

Is bad weather always an extraordinary circumstance?

No — not all weather counts. The weather must be severe and unusual for the time and place — not routine rain, wind, or fog that an airline should anticipate. A freak snowstorm or volcanic ash cloud qualifies. Standard winter weather at northern European airports generally does not. Airlines frequently overclaim on weather — if delays at your airport were widespread but your flight was significantly more delayed than others, the weather excuse may not stand.

Extraordinary Circumstances in Flight Compensation — What Airlines Can (and Cannot) Claim

Q: How do I challenge an extraordinary circumstances rejection?

Ask the airline in writing to: (1) specify precisely what the extraordinary circumstance was; (2) explain why it was unavoidable; (3) explain what reasonable measures they took to avoid the delay; (4) provide documentary evidence. If the airline cannot substantiate all three elements, their extraordinary circumstances defence fails. Escalate to their ADR scheme or the FOS with your written challenge and their response.

The key rule

What counts as extraordinary circumstances?

Extraordinary circumstances are events that: (1) are outside the airline's control, (2) could not have been avoided even with all reasonable measures, and (3) directly caused the delay. The airline must prove all three elements. Genuine examples include ATC strikes, volcanic ash clouds, and extreme unprecedented weather. Technical faults, crew shortages, and routine weather are not extraordinary circumstances — courts have consistently ruled these are the airline's operational responsibility.

❌ Technical faults: NOT extraordinary✓ ATC strikes: extraordinary⚠ Weather: case by case

The definitive guide

Which delay reasons are (and aren't) extraordinary circumstances

Reason given by airlineExtraordinary?Notes

Technical fault / mechanical problem✓ Not extraordinaryWallentin-Hermann ruling: technical problems are the airline's operational responsibility. Only a hidden manufacturing defect qualifies.

Late incoming aircraft✓ Not extraordinaryThe cascade effect of a previous delay is an operational problem within the airline's control. Widely rejected as a defence.

Crew shortage / unavailability✓ Not extraordinaryStaffing is a core airline responsibility. Courts and ADR schemes consistently reject this defence.

ATC strike actionExtraordinaryThird-party ATC strikes (not airline staff strikes) are generally accepted as extraordinary circumstances.

Airline staff strike (own employees)⚠ DisputedPost-Krüsemann v TUI (CJEU 2018), own-airline strikes may not be extraordinary if the airline did not take preventive measures.

Severe and unusual weather⚠ Case by caseMust be severe AND unusual — not routine winter weather. Volcanic ash (2010), unprecedented snowstorms qualify. Standard bad weather does not.

Volcanic ash cloudExtraordinaryAccepted as extraordinary. Airlines must still prove they took all reasonable measures to avoid the delay.

Security threat / terrorist incidentExtraordinaryGenuine security threats imposed by authorities are extraordinary. The threat must be specific and credible — not just a general security level.

Bird strike⚠ Often disputedA bird strike may qualify if it genuinely caused an irreparable technical problem. However, airlines must show the aircraft could not be replaced or repaired in time.

Political unrest at destinationExtraordinaryGovernment-imposed flight bans or closures due to genuine political instability qualify. Precautionary airline decisions do not.

COVID/pandemic restrictionsExtraordinaryGovernment-mandated border closures and flight bans during COVID were accepted as extraordinary. Now largely historical.

The three-part test

The test an airline must pass to use extraordinary circumstances

It's not enough for an airline to point to something unusual. Under UK261 and case law, they must prove three distinct elements:

The extraordinary circumstance actually existed

The airline must specify exactly what the extraordinary circumstance was — not just say "extraordinary circumstances applied". ATC logs, weather reports, NOTAM records, or official authority decisions are the kind of evidence required. Vague claims fail this test.

The extraordinary circumstance directly caused the delay

Even if something extraordinary happened, the airline must show it directly caused your specific flight's delay. A storm at a different airport, or an ATC restriction that didn't apply to your route, doesn't exempt the airline from compensating you.

The airline took all reasonable measures to avoid the delay

This is the most frequently overlooked element. The airline must show they took every reasonable step — rebooking passengers on alternatives, repositioning aircraft, rescheduling crews. If they could have done something to avoid or reduce the delay but didn't, the extraordinary circumstances defence can fail even if an extraordinary event occurred.

Challenge template

How to challenge an extraordinary circumstances rejection

When an airline rejects your claim citing extraordinary circumstances, request written substantiation. Here's a template letter you can adapt:

Template — challenging an EC rejection

Dear [Airline] Customer Relations,

Thank you for your response to my UK261 compensation claim for flight [flight number] on [date].

You have cited extraordinary circumstances as the reason for rejecting my claim. Under UK261 and the case law of Wallentin-Hermann v Alitalia (C-549/07) and subsequent CJEU rulings, I am entitled to ask you to substantiate this claim.

Please provide, in writing:
1. A precise description of the extraordinary circumstance you are relying on;
2. Evidence that this circumstance applied specifically to my flight;
3. A description of the all reasonable measures you took to avoid or reduce the delay.

If you are unable to provide this information within 28 days, I will treat your extraordinary circumstances defence as unsubstantiated and escalate my claim to [AviationADR / the Civil Aviation Authority / Money Claim Online].

My claim remains for [£X per passenger × N passengers = £X total] under UK Regulation 261/2004.

Yours faithfully,
[Your name]

💡

Save every response from the airlineEvery written response you receive — including auto-acknowledgements — is evidence. Airlines' extraordinary circumstances defences frequently crumble under written challenge because they cannot substantiate the three-part test. Keep a dated record of all correspondence.

Key case law

Court decisions on extraordinary circumstances

CaseOutcomeWhat it means for you

Wallentin-Hermann v Alitalia (C-549/07) — CJEUPassenger wonTechnical faults are NOT extraordinary unless caused by a hidden manufacturing defect. Airlines cannot use routine maintenance issues.

Krüsemann v TUI (C-195/17) — CJEUPassenger wonSpontaneous strikes by own airline staff may NOT be extraordinary if the airline could have prevented them through reasonable industrial relations measures.

van der Lans v KLM (C-257/14) — CJEUPassenger wonEven an unexpected technical fault that occurs during flight is not automatically extraordinary — it must be truly unforeseeable and unavoidable.

Pešková v Travel Service (C-315/15) — CJEUMixedA bird strike may qualify as extraordinary if it caused an unexpected technical fault — but the airline must also show it took all reasonable measures after the event.

These rulings by the Court of Justice of the EU (CJEU) were part of retained EU law and remain applicable in UK courts post-Brexit.

FAQs

Extraordinary circumstances — questions answered

The airport was closed due to weather — does that exempt the airline?+

Only if the weather was truly severe and unusual — not routine for that time of year and location. A genuine closure imposed by aviation authorities (e.g. Gatwick closed for fog is a grey area; a freak snowstorm causing runway closure for 48 hours is more clearly extraordinary). The airline must still show it took all reasonable measures, including rebooking passengers on alternatives where possible. If your flight was delayed significantly longer than others in the same conditions, the weather excuse is weaker.

The airline said "operational reasons" — what does that mean?+

"Operational reasons" is often code for a reason the airline knows doesn't qualify as extraordinary circumstances — late crew, aircraft positioning problem, scheduling issue. It is not extraordinary and the airline is effectively conceding compensation is owed by using this phrase. Write back and confirm you understand the delay was for operational reasons (not extraordinary circumstances) and request your UK261 compensation.

The airline offered a different amount to what UK261 requires — is that legal?+

No. UK261 rates are fixed by statute — £220, £350 or £520 per passenger depending on route distance. An airline cannot offer a lower amount and call it "compensation". They can offer the correct statutory amount as full settlement. They can also offer a voucher, but you are entitled to cash instead. If they're offering less than the statutory rate, write back and specify the correct amount you're entitled to.

Related guides

Disclaimer: This guide reflects UK261 as retained in UK law and leading CJEU/UK court decisions. Individual cases depend on specific facts. Not legal advice. Always verify the current status of case law and regulation with a qualified adviser.