The Montreal Convention sets forth an airline’s liability for a passenger’s injury or death on an international flight.  Under the Convention, the airline’s liability does not depend on whether the airline was “negligent” or otherwise “at fault” for the injury or death.  Rather, the airline is automatically liable, provided that the injury was caused by an “accident.”  The case law interpreting the Convention defines “accident” as “an unexpected or unusual event. . . external to the passenger.”

Arzu v American Airlines is the latest case examining what qualifies as an “accident” for purposes of the convention.  A 14-year-old boy suffered a medical emergency on board a flight from Honduras to Florida.  He died on board.  A family member sued the airline alleging the airline was liable under the Montreal Convention.  First, the family alleged that the airline’s on-board response to the emergency was so slow, chaotic, and ineffective that it should be considered “an unexpected or unusual event” that qualifies as an “accident.”  The court considered and rejected the argument.

Crew inaction can be an Article 17 accident.  But  “unusual  circumstances”  must  “elevate  the  willing  inaction of  airline  personnel   from   mere   inertia—from a    non-event—to   an   event   both   unexpected  and  unusual.”  In  other  words,  crew  inaction  is  an  accident  only when: (1) unusual circumstances elevate it to an unexpected and unusual event, and (2) the inaction is willing.

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True,  some  evidence  suggests  that  attendant  Blanchard  could  have  responded faster. Or Anderson could have alerted the pilots sooner. Or the pilots  could  have  contacted  the  on-call  physician.  Yet  Arzu  identifies  no  circumstances that elevate the crew’s inaction to “an event both unexpected and unusual . There is no evidence  that  the  flight crew’s  response  was  unusually  slow  or  chaotic  compared to other crew’s responses to similar emergencies. [Citations omitted.]

The family’s second argument was that the on-board AED was not functioning properly and that its failure to operate properly was a qualifying “accident” that caused or contributed to the boy’s death.  The court agreed that, depending on the evidence produced at trial, the AED’s failure, in violation of FAA regulations, could be considered an “unexpected or unusual event.”

The case is Arzu v. American Airlines, No. 25-10606 (5th Cir. 2026)