A cabin suddenly fills with fumes.  Passengers get ill.  The fumes eventually clear.  But for some, the symptoms persist long after the flight is over.  Others will first develop symptoms weeks or months later, and may not even relate their symptoms to their flight.  These passengers are all the victims of what has become known as a "fume event."

Here’s what happens: Airlines pump air into the cabin.  The air is a mix of fresh air and air that has been compressed by the aircraft’s engines–known as "bleed air."  But when the air distribution system malfunctions, toxic chemicals found in the aircraft’s engine oil can be heated and pumped through the airplane, creating a fume event. Bleed Air Schematic According to the Wall Street Journal:

Airline companies and jet manufacturers say that fume events are rare, and that when they do occur, air quality still exceeds safety standards. But unions representing pilots and flight attendants say the chemicals entering the aircraft cabin can endanger the health of flight crews and passengers.

For years, the airlines denied that fume events occurred at all  Then, the airlines admitted the events occurred, but denied that they were dangerous.  But fume events appear to be happening with more and more frequency, and the airlines seem to be more willing to admit that there is a danger to the flying public.  Regardless, in March the US Senate approved a measure that would require the FAA to study cabin air quality generally and fume events in particular.

The increased focus on fume events is for the most part due to injuries that American Airlines flight attendant Terry Williams suffered in April 2007.  She recently filed a lawsuit against Boeing, the manufacturer of the aircraft on which she was flying.  Williams is represented by Alisa Brodkowitz, a prominent aviation lawyer in Seattle, who is perhaps the nation’s leading expert on fume events.

What about the passengers of American Airlines Flight 49, who were involved in a fume event today while travelling from Paris to Dallas-Forth Worth? 

Because the flight was international, the Montreal Convention applies.  The Convention requires the airlines to offer fair compensation to anyone injured as a result of an "accident."  An accident is an "unexpected or unusual event or happening" on board the aircraft that is "external to the passenger."  A fume event would likely qualify (though some airlines contend that fume events are "normal".)

The flight attendants will have a tougher go of obtaining compensation for any long lasting injuries they might have suffered.  They can’t sue the airlines due to workers’ compensation laws.  That means their only claim is a product defect claim against Boeing, the aircraft’s manufacturer.