Airbus and Air France pleaded have not guilty to manslaughter at the start of a new two-month trial over France's worst air disaster, 16 years after a Paris-bound jet crashed into the Atlantic, killing all passengers and crew. The chief executives of both the plane manufacturer and the airline paid tribute to the suffering of bereaved families but denied any criminal responsibility for the crash. "It is forever engraved in our memories," Air France CEO Anne Rigail told the packed high-windowed courtroom. But the first trial more than a decade after that also shed light on discussions even before the accident between Air France and Airbus about growing problems with the sensors, or "Pitot probes", that generate speed readings. "If you take one of those acts of negligence away, then the accident would never have happened."