Air France and Airbus are due to go on trial on Monday over charges of involuntary manslaughter, more than 13 years after a plane carrying 228 people plunged into the sea while flying from Rio de Janeiro to Paris.
What happened to the flight?
Flight AF447 drowned in the Atlantic Ocean on June 1, 2009, killing 12 crew members and 216 passengers.
The plane had headed into an "intertropical convergence zone" that often produces volatile storms with heavy precipitation.
Over the following two years, the fuselage and the black box flight recorders were recovered.
An inquiry found that the crash happened due to errors made when the pilots were disoriented by the Pitot speed-monitoring tubes that had frozen over in a thick cloud.
As a storm engulfed the plane, ice crystals present at high altitudes disabled the pitot tubes, blocking speed and altitude information. The autopilot disconnected.
The crew resumed manual piloting but with the wrong navigation data. As the plane went into an aerodynamic stall, its nose pitched upward and then plunged.
The investigating magistrates had dropped charges against Air France and Airbus, which led to outrage among victims' families. After prosecutors appealed this decision in 2021, a Paris court ruled that there was sufficient evidence for the trial to go ahead.
What is expected in the trial?
Several aviation experts and pilots are due to give testimony in the hearings that will last over two months. If convicted, each company faces a maximum fine of $220,000 (€226,000).
Testimony will also be heard from some of the victims' families, who are civil plaintiffs in the case.
"The message is also to make companies that think they're untouchable understand: 'You're like everyone else and if you make mistakes, they will be punished," Ophelie Toulliou, who lost her brother on the flight, told the AFP news agency.
Air France is accused of not having implemented training in the event of icing of the pitot probes despite the risks.
Airbus is accused of having known that the model of pitot tubes on Flight 447 was faulty, and not doing enough to inform airlines and their crews about it and to ensure training to mitigate the resulting risk.
The crash prompted an overhaul of training protocols across the industry, in particular to prepare pilots to handle the intense stress of unforeseen circumstances. Pilots are also now required to continually practice stall responses on simulators.
Nelson Marinho, who lost his son in the accident, is angry that no company executives will be tried.
"They have changed various directors, both at Airbus and Air France, so who will they arrest? No one. There won't be justice. That's sadly the truth,'' he told the AP news agency.