BRUSSELS, BELGIUM — In a recent ruling by the European Union's top court, airlines cannot be exempted from compensating delayed passengers even if the delay is caused by the unexpected death of a co-pilot just before a scheduled flight.

The EU Court of Justice declared that such a tragic event does not constitute an "extraordinary circumstance" warranting exemption. Instead, the court compared it to any unexpected illness that could affect a vital crew member, which is inherent in the normal operations of an airline.

Since a 2009 landmark judgment requiring flight delays to be at least three hours long for passengers to claim compensation, EU judges have been overwhelmed with cases seeking clarification on when passengers can claim compensation and what circumstances are considered extraordinary enough to exempt airlines from liabilities.

Over the past decade, the court has ruled that bad weather, a bird strike, or a passenger biting someone on the plane are extraordinary enough to grant exemptions, while unannounced strikes by staff causing long delays are not.

The recent dispute involves Portuguese carrier TAP SA, where passengers sought compensation after their flight from Stuttgart, Germany to Lisbon, Portugal was canceled due to the sudden death of the co-pilot just two hours before the scheduled flight. 

TAP claimed "extraordinary circumstances," but the court ruled otherwise. With the flight originating outside TAP's usual base and no immediate replacement staff available, passengers had to wait for a new crew to be flown in, resulting in a departure more than 10 hours later than planned.