The board reads the same way a claim does. If your cause sits in the amber row, the airline owes no cash — but still owes care and a refund. If it's in the red row (staff strike, crew shortage, routine technical), the airline must pay the full amount, and any "extraordinary circumstances" letter is a defence it has to prove.
First, work out which row you're in using the guide below — the contested cases (routine technical faults, airline staff strikes, knock-on delays) are exactly where airlines wrongly claim "extraordinary circumstances" and lose when challenged. Then decide how to claim. For a clear-cut case, claim yourself and keep 100%. For a rejection citing extraordinary circumstances — where you'd need to escalate to a national body or court — a no-win-no-fee service does the fight for a cut of the payout.
One thing worth knowing if you've been researching providers: ClaimCompass was acquired by AirHelp in November 2024, so the two names now point to the same operation. AirHelp checks eligibility free and only charges if it wins.
Check your compensation free with AirHelp → How the burden of proof worksBest when the airline isn't disputing liability. Write to the airline citing EC 261/2004, state the delay length and distance, and request the amount. Free, and often paid within weeks.
Best when the airline has rejected you citing extraordinary circumstances, or the case needs escalation to a national body or court. The service absorbs the work; you pay only if it wins.
Extraordinary circumstances are events outside the airline's reasonable control that could not have been avoided even if all reasonable measures had been taken. The category is defined in the regulation's recitals as including things like political instability, meteorological conditions, security risks, unexpected safety shortcomings, and strikes affecting operation. It has been substantially refined by Court of Justice rulings since 2005.
The legal test, developed across many CJEU cases, has two parts. First, the event must be outside the airline's normal commercial activity — not an event that is part of normal operations or that the airline should reasonably anticipate. Second, the event must not have been avoidable by reasonable measures the airline could have taken; the airline must demonstrate it took all reasonable steps to prevent or mitigate the disruption.
Both parts must be satisfied. An event can be unusual but still avoidable through reasonable planning. Conversely, an event that was unavoidable in the moment may have been preventable through earlier planning. The CJEU has been generally strict in applying this test, finding many initial airline defences to be inadequate.
Crucially, the defence applies only to the cash compensation obligation — not to the care obligation (food, drink, hotel) or to the refund/rerouting right. Even where an extraordinary circumstance is established, the airline must still provide care and offer the passenger a refund or rerouting. This is the amber row on the board above.
The major categories of events that generally do count as extraordinary, when they directly affect the specific flight, are severe weather (heavy snow, fog, thunderstorms, hurricanes that prevent safe operation — the weather must affect the flight in question, not generic weather elsewhere); air traffic control restrictions (ATC strikes, capacity restrictions, slot delays imposed by third parties); airport closures for security, safety or weather; security incidents such as bomb threats or terror alerts; political instability, war, civil unrest or government flight bans; and third-party strikes (air traffic controllers, non-airline airport ground staff, security personnel, fuel suppliers).
Two more qualify under narrower conditions. Bird strikes: the CJEU ruled in Pešková v Travel Service (2017) that a bird strike requiring inspection is generally extraordinary, provided the airline reasonably managed the situation. Hidden manufacturing defects: aircraft defects inherent to the design or emerging from a manufacturing fault outside the airline's knowledge, typically requiring a fleet-wide recall — a narrow category, rarely invoked successfully. Medical emergencies requiring diversion generally qualify too.
Routine technical and mechanical issues. The Wallentin-Hermann ruling (2008) established that ordinary technical problems — even ones that emerge suddenly and could not be predicted on the day — are part of the airline's normal commercial activity. The airline is expected to maintain its fleet to a standard that anticipates technical issues. Only hidden manufacturing defects, not normal wear-and-tear or maintenance issues, qualify.
Strikes by the airline's own staff. Multiple CJEU rulings (Krüsemann 2018, TAP Portugal 2024, and others) have established that strikes by an airline's pilots, cabin crew, ground staff or other employees are NOT extraordinary circumstances. The airline employs these staff and has tools — negotiation, scheduling, contingency planning — to manage labour relations. Wildcat strikes are covered by this principle too.
Crew shortages. If the airline lacks enough crew to operate the flight — whether due to illness, scheduling or earlier delays — this is generally an operational issue within its control.
Knock-on delays from earlier disruption. If the same aircraft was delayed on an earlier rotation and a later flight is consequentially delayed, the original delay's extraordinary status (if any) does not automatically transfer. The airline must demonstrate the connection and that no reasonable measures could have recovered the schedule. The TUI v Skyland (2013) line of cases established that downstream delays from upstream operational issues remain the airline's responsibility.
Overbooking. Discussed in our denied-boarding article — overbooking is the airline's commercial choice and never an extraordinary circumstance.
Yes. The burden of proof is firmly on the airline. The passenger does not have to prove the disruption was within the airline's control; the airline must prove it was outside its control AND that all reasonable measures were taken. This is a significant practical advantage for passengers — many initial rejections cite extraordinary circumstances without supporting evidence, and a passenger who pushes back firmly and asks for documentation often succeeds.
Specifically, the airline must provide evidence of the extraordinary event itself (weather data, ATC restrictions, strike documentation, security reports); the causal link between the event and the specific disrupted flight; and the measures it took to mitigate. Generic statements such as "due to operational reasons" or "due to extraordinary circumstances" without specific evidence are typically insufficient.
National enforcement bodies and courts have repeatedly held that the evidentiary burden is real and meaningful. An airline that claims extraordinary circumstances without producing the underlying documentation generally loses on that ground alone. The proof requirements surface during the claim process — at initial submission, then at each escalation stage, with the bar rising at each step.
Because the burden sits with the airline, a rejection letter citing "extraordinary circumstances" is not the end of your claim — it's the airline's opening move. In the contested categories (routine technical, staff strikes, knock-on delays), that move frequently fails on escalation. If you don't want to run that fight yourself, this is exactly the point at which a no-win-no-fee service earns its cut. You can have AirHelp check the claim for free before deciding.
No. Weather is among the most commonly claimed extraordinary circumstances, but the analysis is more nuanced than "there was bad weather, therefore no compensation." The weather must have directly affected the specific flight — severe weather at the airline's hub, at a different airport, or on a different route is not enough. It must have made operating the flight genuinely unsafe, not merely prompted caution. And the airline must show it took reasonable measures to mitigate: alternative aircraft, crew, slots, or rebooking on competitor flights where possible. An airline that simply waited for the weather to clear may struggle to defend the claim.
Categories that almost always qualify: hurricanes and named storms with airport closure; widespread fog closing runways; volcanic ash clouds; ice storms shutting down ground operations. Categories that often do not: summer thunderstorms at airports that routinely handle them; minor snow at airports that should be equipped for it; light fog the airline could have planned around; routine crosswinds.
It depends entirely on who is on strike. Third-party strikes are generally extraordinary — air traffic controllers, non-airline airport ground handlers, security personnel, fuel suppliers, all imposed on the airline from outside. Airline employee strikes are generally NOT extraordinary. The Krüsemann ruling (2018) and the TAP Portugal ruling (2024) firmly establish that strikes by pilots, cabin crew, maintenance or other airline employees are part of the airline's normal management of its activities.
This holds even for wildcat strikes — unauthorised action without union backing. The CJEU has been consistent that the employment relationship and management responsibility are what matter, not whether the strike was authorised. The same principle applies to non-strike crew unavailability: a crew member calling in sick, exceeding duty hours, or missing a connection. The airline is expected to plan for normal staffing variation. Sympathy strikes by airline staff in response to industrial action elsewhere are an unsettled edge case; passengers facing this should seek specific advice.
The general rule is that technical problems are NOT extraordinary circumstances. The Wallentin-Hermann ruling (2008) established the foundational principle: technical problems are part of normal commercial activity, and the airline is expected to maintain aircraft to a standard that anticipates ordinary technical issues. This holds even for faults that emerge unexpectedly on the day — the unexpected nature does not make them extraordinary, because the maintenance programme should account for the statistical likelihood of surprises.
The narrow exceptions are hidden manufacturing defects that emerge across a fleet and require manufacturer-level remediation (typically a formal safety bulletin or recall), and technical damage caused by an event that is itself extraordinary — a lightning strike, bird strike, or runway-debris incident. Where the technical issue was caused by an extraordinary event, the classification follows the cause. For a rejection on technical grounds, the question to press is: what specifically caused the fault, and was that cause itself extraordinary? Airlines that simply assert "technical issue" without specifying are typically not meeting the evidentiary burden.
ATC and airport closures are among the clearer extraordinary-circumstances categories, because air traffic management and closures are imposed on airlines by third parties. But the airline must still demonstrate the specific impact on the flight — generic ATC delays elsewhere in Europe do not exempt a specific flight — and show reasonable mitigation. Where an ATC restriction was predictable (a strike announced in advance, a known capacity limit), the airline is expected to adjust schedules or swap aircraft. Knock-on delays from ATC are particularly contested: the airline must show both that the original delay was extraordinary and that no reasonable measures could have prevented the propagation. The chain often breaks at that evidentiary point.
The TUI v Skyland (2013) and subsequent cases established that downstream delays caused by upstream issues remain the airline's responsibility unless it can show that both the original disruption AND the downstream propagation were extraordinary and unavoidable. This significantly limits the defence, because airlines frequently experience cascading delays — one aircraft's delay propagating through its rotation across the day — and then point to an early-morning event as the "cause" of an evening delay.
The CJEU's position is that the airline must show the original disruption was extraordinary; the propagation was unavoidable by reasonable measures (substitute aircraft, crew changes, schedule adjustments); and the specific flight was directly affected by the original event rather than by intervening operational choices. This is a high bar. Many defences citing "earlier weather" or "earlier ATC" for evening delays have been rejected because the airline had hours to adjust and chose not to.
Yes, and successfully in many cases. Step 1 — request documentation. Write back asking for specific evidence: details of the alleged event, evidence of its impact on your flight, and the measures taken to mitigate. Many airlines fold here because the documentation doesn't exist or doesn't support their position. Step 2 — escalate to the National Enforcement Body (the Civil Aviation Authority in the UK, the relevant national body in EU states), which assesses the evidence and issues a non-binding opinion. Step 3 — court action via small claims or the European Small Claims Procedure (cross-border cases under €5,000), which has been consistently favourable to passengers where airlines cannot meet the burden.
The combination is what makes EU261 work. Initial airline rejection rates are high; after NEB review and escalation, eventual payment rates are much higher. This escalation chain is precisely what a no-win-no-fee service handles for you — which is why a commission of around 35% is defensible for passengers who would not pursue the case alone. If you'd rather not manage the back-and-forth, AirHelp runs the whole escalation on a no-win-no-fee basis; if your case is clear-cut, our honest DIY-vs-service comparison shows when doing it yourself is the better call.
Events outside the airline's reasonable control that could not have been avoided even if all reasonable measures had been taken. These typically include severe weather, air traffic control restrictions, security incidents, political instability, third-party strikes, and bird strikes. The category has been narrowed by Court of Justice rulings to exclude things like routine technical issues and airline staff strikes.
No. Multiple Court of Justice rulings have established that strikes by an airline's own pilots, cabin crew, or other employees are NOT extraordinary circumstances. Only third-party strikes (air traffic control, airport security, fuel suppliers) generally qualify.
Generally no. The Wallentin-Hermann ruling established that ordinary technical problems are part of the airline's normal commercial activity. Only hidden manufacturing defects requiring fleet-wide recall typically qualify, and that is a narrow category.
The airline. The burden of proof is firmly on the carrier to provide evidence of the event, its specific impact on the flight, and the measures taken to mitigate. Generic statements without supporting documentation are typically insufficient.
For a clear-cut claim where the airline is not disputing liability, claiming yourself is free and straightforward — you keep 100% of the compensation. Use a no-win-no-fee company when the airline has rejected the claim citing extraordinary circumstances, when the case needs escalation to a national enforcement body or court, or when you simply do not want to manage the process. Companies typically take 35% or so of the payout, but there is no cost if they lose, and they absorb the escalation work. The honest rule: try it yourself first for straightforward cases; hand a contested extraordinary-circumstances rejection to a service.
ClaimCompass was acquired by AirHelp in November 2024. Claims and the ClaimCompass brand have been consolidated under AirHelp's operations, and the ClaimCompass site now routes to AirHelp. If you were researching ClaimCompass as a flight-compensation company, AirHelp is the entity that now handles those claims.
If your cause was a staff strike, a crew shortage, a routine technical fault, or a knock-on delay, the airline has to prove its defence — and often can't. Check your claim's worth in a couple of minutes; it's free, and you only pay if it pays out.
Check my compensation free →General information about EU Regulation 261/2004 and the equivalent UK regulation, not legal advice. Case-law positions and compensation amounts reflect publicly available information at time of publication and may change; verify current details with your national enforcement body before acting. This article contains affiliate links — if you claim through a partner link we may earn a commission at no additional cost to you.
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