This file photo taken on June 12, 2009 shows journalists reporting the first wreckage pieces and objects of the Air France A330 aircraft, flight AF447, lost in midflight over the Atlantic ocean and recovered from the sea, at the airbase hangar, in Recife, northeastern Brazil. There were 228 people of 32 nationalities – including 58 Brazilians – who died died when the Airbus A330 crashed in the middle of the Atlantic on June 1, 2009. (MAURICIO LIMA / AFP)

PARIS – A French criminal court opened the historic manslaughter trial of Air France and planemaker Airbus on Monday, with relatives demanding justice more than 13 years after an A330 passenger jet ploughed into the Atlantic, killing everyone on board.

The heads of both companies pleaded not guilty to involuntary corporate manslaughter after officials read out the names of all 228 who died when AF447 vanished during a night-time equatorial storm en route from Rio de Janeiro to Paris on June 1, 2009.

The heads of both companies pleaded not guilty to involuntary corporate manslaughter after officials read out the names of all 228 who died when AF447 vanished during a night-time equatorial storm en route from Rio de Janeiro to Paris on June 1, 2009

Families of several victims shouted protests including "shame" and "too little, too late" as Air France Chief Executive Anne Rigail and then Airbus Chief Executive Guillaume Faury expressed condolences in opening statements to the nine-week trial.

"Thirteen years we have been waiting for this day and we have prepared for a long time," said Daniele Lamy, who lost her son in the accident, before the two-hour opening hearing.

ALSO READ: Boeing cites risks in design of newest Airbus jet

After a two-year search for the A330's black boxes using remote submarines, investigators found pilots had responded clumsily to a problem involving iced-up speed sensors and lurched into a freefall without responding to "stall" alerts.

But France's BEA accident agency also revealed earlier discussions between Air France and Airbus about the reliability of the probes, and made dozens of safety recommendations from cockpit design to training and search-and-rescue.

Summarising an earlier stage of the judicial process, a Paris judge said Airbus had been accused of reacting too slowly to a rise in the number of icing incidents, which hampered speed displays, and under-estimated the impact on startled pilots.

Preliminary findings had meanwhile called into question the efforts taken by the airline to ensure pilots were well trained.

The relative roles of pilot or sensor error will be key to the trial, exposing differences that insiders say plunged Airbus and Air France into in-fighting behind the scenes for over a decade.

ALSO READ: Boeing 737 crashes raise tough questions on aircraft automation

Airbus blames pilot error for the crash while the flag carrier claims confusing alarms overwhelmed the pilots.

Lawyers warned against allowing the long-awaited trial – which is going ahead after a decision to abandon the case was overturned – to sideline family members represented on day one.

Handout picture released June 9, 2009 by the Brazilian Navy showing a piece of the tailfin of the Air France A330 aircraft that crashed June 1 while in midflight over the Atlantic ocean, being hoisted by a Navy rescue vessel. (HO / BRAZILIAN NAVY / AFP)

"It's a trial where the victims must remain at the center of debate. We don't want Airbus or Air France to turn this trial into a conference of engineers," said lawyer Sebastien Busy.

It is the first time French companies face trial for "involuntary manslaughter" following an air crash. Victims' families say individual managers should also be in the dock.

Relatives also brushed off the maximum fine of 225,000 euros (US$220,612) each company could receive – equivalent to just two minutes of pre-COVID revenue for Airbus or 5 minutes of passenger revenue for the airline. Undisclosed larger sums have also been made in compensation or out-of-court settlements.

ALSO READ: Boeing promises upgrade as more countries ground fleets

"It's not the 225,000 euros that will worry them. It's their reputations…that's what's at stake for (Air France and Airbus)," said families lawyer Alain Jakubowicz.

"For us it is about something else, the truth…and ensuring lessons are learned from all these great catastrophes. This trial is about restoring a human dimension," he told reporters.

AF447 sparked a rethink about training and technology and is seen as one of a handful of accidents that changed aviation

Pilot training 

AF447 sparked a rethink about training and technology and is seen as one of a handful of accidents that changed aviation, including industry-wide improvements in handling lost control.

Centre-stage is the mystery of why the crew of three, with more than 20,000 hours of flying experience between them, failed to understand that their modern jet had lost lift or "stalled".

That required the basic manoeuver of pushing the nose down instead of yanking it up as they did for much of the fatal four-minute plunge towards the Atlantic in a radar dead-zone.

France's BEA has said the crew responded incorrectly to the icing problem, but also did not have training needed to fly manually at high altitude after the autopilot dropped out.

READ MORE: Fatal air crash renews safety doubts

It also highlighted inconsistent signals from a display called the flight director, which has since been redesigned to switch itself off in such events to avoid confusion.