Airbus faces manslaughter charges over the 228 passengers and crew killed when Air France Flight 447 came down off the coast of Brazil in 2009.
Preliminary charges have been laid by a judge in France to begin a formal investigation into the European aerospace giant.
Airbus chief executive Thomas Enders confirmed the investigation, saying: “We firmly disapprove of this decision, which we consider premature.”
The Air France flight from Rio de Janeiro to Paris came down in the Atlantic Ocean on 1 June 2009.
The cause of the accident is not fully known, though automatic messages retrieved from the computers of the A330-200 show it was receiving false air speed readings from sensors, which may have iced over. Investigators have said these errors may have been part of the reason the plane crashed.
Airbus says no one can know for sure what happened as the plane’s “black boxes”, which monitored events during the flight, have not been recovered.
The investigation comes as specialists prepare to launch a fourth search for the plane’s voice and data recorders, due on March 20, using a German mini-submarine, which will scour the ocean floor at depths of up to 4,000 metre. Air France and Airbus will foot the €7 million bill.
“We are convinced if we find the black boxes we’ll be able to reconstruct what really happened on this tragic flight,” said Airbus chief executive Tom Enders.
A third search of the ocean floor to try to locate the wreckage ended in failure last May. Only three per cent of the plane has been recovered, along with 50 bodies.