The FBI has begun a criminal investigation into the Airbus crash in November last year that killed 265 people in New York.
Thousands of used aircraft parts have been seized by police in Italy. Italian and American investigators are exploring a link between the alleged sale by three companies based in Rome of second-hand parts to national and international airlines and two air crashes – the one in the New York suburb of Queens and a domestic airline accident near Genoa in 1999, in which four died.
Preliminary evidence in the case of the American Airlines Airbus A300 that nosedived into the Rockaway Beach residential area in Queens pointed to an accident. Investigators focused on engine failure and rudder malfunction as possible causes.
But American aviation officials in Washington confirmed at the weekend that an investigation into possible criminal activity was now under way. Diane Spitalieri, of the US Federal Aviation Authority (FAA), said: "It's an FBI investigation and all I can say is that we're co-operating with those authorities. If it's an unapproved aircraft part that is being sold, that is a criminal act."
Aircraft parts were seized in a raid by 150 police officers on a warehouse belonging to Panaviation at Fiumicino airport in Rome on Saturday. That followed a similar seizure on Friday when police raided a ship in Naples.
Investigators say they believe the parts are sold with false documentation as new to national and international airlines, or with the false claim that they have been properly inspected when in reality they have been stripped from old planes by unqualified people.
Police claimed staff found stripping an Airbus A300 plane belonging to Panaviation in the raid on Fiumicino on Saturday were not qualified to do the job.
Two shipping containers were seized containing parts from six Airbus A300s that were allegedly unfit to fly. On Friday, investigators raided a ship in Naples – believed to be on its way to America – and said they uncovered three containers full of plane parts that were supposed to be scrapped.
The Italian Air Safety Authority said the scandal "will shake the whole aviation world". Financial police said three companies, Panaviation, New Tech Italia and New Tech Aerospace, had all obtained and reconditioned a large quantity of plane parts and sold them on to Italian airlines including Alitalia, Minerva and Meridiana as well as European and American airlines.
Six people have already been arrested and another four are under investigation.
Enzo Fregonese, the head of Panaviation, who is under house arrest in Rome, said he was unable to comment.
The Italian police said the parts seized in the two raids were worth €2.7m (£1.7m).
The investigation may shed new light on the fate of the Minerva airlines jet that plunged off the runway into the sea at Genoa in 1999. The pilot was found guilty of malpractice, but he said there were problems with the braking system.Reuse content