EU261/UK261 compensation is not owed if the disruption was caused by “extraordinary circumstances which could not have been avoided even if all reasonable measures had been taken” (Article 5(3)). Airlines invoke this constantly — often wrongly. Here’s the honest line, based on EU Court of Justice (CJEU) case law, so you neither overclaim nor accept a bogus “no”.
Usually IS extraordinary — no compensation
(You may still be owed care and a refund.)
- Severe weather that makes the flight unsafe (storms, fog, snow, volcanic ash — McDonagh).
- Air-traffic-control restrictions or strikes, airport closures, and strikes by people outside the airline (airport staff, ground handlers, ATC).
- Security risks, terrorism, sabotage, and political instability.
- Bird strikes (Pešková) and runway hazards not caused by the airline (debris, fuel on the runway — Germanwings, Moens).
- A hidden manufacturing defect revealed by the maker or a safety authority (a narrow exception).
- An unruly passenger forcing a diversion (TAP), unless the airline contributed.
Usually is NOT extraordinary — compensation IS still owed
- Most technical / mechanical faults. Routine breakdowns and maintenance problems are “inherent in the normal exercise” of running an airline (Wallentin-Hermann; van der Lans; Finnair) — even unexpected ones. This is the single most common wrongful refusal.
- Strikes by the airline’s OWN staff — including a “wildcat” sickout after a restructuring announcement and lawful union strikes by the carrier’s own crew (Krüsemann; Airhelp; Eurowings).
- Operational/scheduling issues — crew rostering, knock-on delays from the aircraft’s earlier rotation (unless the original cause was itself extraordinary), or a collision with the airline’s own boarding stairs (Siewert).
What this means for your claim
- The burden of proof is on the airline to show the cause was extraordinary and that it took all reasonable measures (e.g. trying to re-route you).
- A vague “operational reasons” or “technical problem” is not a valid refusal — ask the airline to state the specific cause, then check it against the lists above.
- Even when compensation is genuinely excused, you keep the right to care and a refund/re-routing.
“It was a technical issue” usually means they still owe you. Don’t accept that line at face value — most technical faults are not extraordinary under Wallentin-Hermann. Reply asking for the specific cause and the reasonable measures taken; if it’s an ordinary mechanical fault or their own staff’s strike, restate your claim and escalate if needed.
These are EU/UK concepts. US flights have no equivalent compensation scheme — see US passenger rights.