Prosecutors recommend trial for Air France over 2009 crash: judicial sources

French prosecutors have recommended that Air France face trial for manslaughter and negligence over the 2009 crash of a flight from Rio de Janeiro to Paris in which 228 people died, judicial sources told AFP.

They concluded that Air France was aware of technical problems with a key speed-measuring instrument on its Airbus A330 plane, but had failed to inform or train pilots on how to resolve the issue, according to an investigation document seen by AFP.

Flight AF447 plunged into the Atlantic during a storm on June 1, 2009, with a defect with the plane's Pitot tubes -- which enable pilots to monitor their speed -- found to be the cause of the crash.

It took two years to find the wreckage of the plane off Brazil which was eventually located by remote-controlled submarines at a depth of 3,900 metres.

The prosecutors recommended dropping the case against Airbus, despite demands from the families of victims that the aircraft manufacturer should also be held accountable for the crash.

Both companies had been charged with manslaughter in 2011.

In a legal case that is now into its 10th year, investigating magistrates who are in charge of the case must now decide whether to follow the recommendations of prosecutors and bring the case to trial.

Air France will also be able to appeal any decision to bring the case to court.

A report from French air crash investigator BEA in 2012 concluded that the ill-prepared crew had failed to react correctly when their Airbus stalled and lost altitude after the speed sensors froze up.

Aircraft safety has been in the spotlight this year after two crashes involving the 737 MAX plane from US aircraft manufacturer Boeing, which has led to the global fleet of the aircraft being grounded as a result.