Airlines will have to prove technical problems were totally unforeseen if they are to cite them as an excuse for wriggling out of paying compensation for last minute cancellations.
Until now they have sometimes claimed such problems qualify as "extraordinary circumstances", which would exempt them from coughing up under EU regulations.
This loophole has been closed - partially at least - by the European Court of Justice. While it recognises that some technical difficulties may be totally beyond an airline's control - such as when a manufacturer discovers a fault which demands the grounding of aircraft - the court has ruled they will need to prove it.
Its judgement reads: "The onus is on the party seeking to rely on them to establish that, even if it had deployed all its resources in terms of staff or equipment and the financial means at its disposal, it would clearly not have been able – unless it had made intolerable sacrifices in the light of the capacities of its undertaking at the relevant time – to prevent the extraordinary circumstances with which it was confronted from leading to the cancellation of the flight.
"The fact that an air carrier has complied with the minimum rules on maintenance of an aircraft cannot in itself suffice to establish that that carrier has taken all reasonable measures so that it is relieved of its obligation to pay compensation."
The decision follows a case brought against the Italian airline, Alitalia. It was brought originally by a passenger who was informed five minutes before departure that a flight booked from Vienna to Brindisi had been cancelled.
The passenger and her family arrived nearly 4hrs late. The airline refused to pay €250 Euros compensation and €10 for phone calls.
The judgement says the cancellation resulted from a complex engine defect which had been discovered the day before during a check. Alitalia had been informed of the defect during the night before the flight. The repair of the aircraft necessitated the dispatch of spare parts and engineers.
It says the resolution of a technical problems caused by failure to maintain an aircraft must therefore be regarded as inherent in the normal exercise of an air carrier’s activity. Consequently, technical problems which come to light during maintenance or on account of failure to carry out such maintenance do not constitute, in themselves, "extraordinary circumstances".
European Union rules cover all flights from EU airports and those to Europe from elsewhere provided the airline is EU based and the passenger has not received any compensation in a third country. Compensation is due unless the carrier informs the passenger of cancellation two weeks or more before departure - or offers an alternative flight that does not delay the traveller more than 2 or 4 hours (depending on whether cancellation is notified within 7 or 14 days of departure).
The amount of compensation ranges from €250 to €600, depending on the length of the flight.