Air France and aircraft maker Airbus will go on trial in Paris on Monday.
The French companies face charges of “involuntary manslaughter” over the 2009 crash of a flight from Brazil, which killed all 228 people aboard.
The case focuses on pilot training and a defective speed monitoring probe, which was quickly replaced on planes worldwide in the months after the accident.
Flight AF 447 from Rio de Janeiro to Paris plunged into the Atlantic Ocean during a storm in the early hours of 1 June 2009, after it encountered strong turbulence.
The A330 was carrying 12 crew members and 216 passengers, including 61 French citizens.
It was Air France’s deadliest crash in history.
Some of the victim’s families have said the court case is the “light at the end of a long tunnel”.
“Thirteen years later, we have a trial, a trial that, for me, is not that interesting, personally, since it will not bring my daughter back to me,” says Corinne Soulas, a mother of a crash victim.
“But I think it is important, once again, to remember this accident in people’s minds, to bring it back to life and then, above all, to define the responsibilities, because there were responsibilities that need to be clarified.”
Air France and Airbus were charged during an inquiry into the crash, with experts determining it resulted from mistakes made by pilots after they became disorientated by a temporary loss of data from iced-up sensors.
Both companies have denied any criminal negligence and investigating magistrates overseeing the case dropped the charges in 2019, attributing the crash mainly to pilot error.
That decision infuriated victims’ families. In 2021 a Paris appeals court ruled there was sufficient evidence to allow a trial to go ahead.
The AF447 crash sparked a broad rethink about training and technology and is seen as one of a handful of accidents that changed aviation.