US airline Continental and five individuals go on trial in France later over the crash of an Air France Concorde nearly 10 years ago.
The jet took off in flames from Paris Charles de Gaulle airport and crashed minutes later, killing 113 people.
An official report said Concorde had hit a metal strip from a Continental plane that had taken off earlier.
But Continental's lawyers say they can prove the supersonic jet caught fire before it struck the titanium strip.
The stricken Concorde flight 4590 crashed in the town of Gonesse in July 2000, hitting a hotel and killing four people there as well as all 109 on board.
Most of the passengers were German tourists heading to New York to join a luxury cruise to the Caribbean. Nine French crew members also died.
The entire fleet of Concordes was grounded until an inquiry established that one of the plane's tyres had burst, causing debris to shoot out and rupture a fuel tank.
The crash occurred shortly after take-off from Charles de Gaulle airport
Leaking kerosene then ignited and caused the catastrophe.
After nearly a year and a half out of service, in November 2001, the jets took to the air once more with new reinforced fuel tanks, but inquiries continued.
In December 2004 a judicial investigation concluded that a piece of metal left on the runway by another aircraft had caused one of Concorde's tyres to burst and shred.
Investigators said the 43cm (17in) metal strip had fallen from the engine casing of a Continental Airlines DC-10 and in March 2008 a French public prosecutor asked judges to bring manslaughter charges.
Houston-based Continental Airlines is denying responsibility.
Olivier Metzner, a lawyer for Continental, said he would challenge the official view that the metal strip led to the crash.
"We are going to fight it and establish that the Concorde caught fire eight seconds before this scrap of metal met with the Concorde - so about 700m (2,300ft) before," he said.
This is denied by Air France, which is not facing charges.
As well as Continental, five individuals are being prosecuted.
They include John Taylor, the Continental mechanic who allegedly fitted the metal strip to the DC-10, and Stanley Ford, a maintenance official from the airline.
Also facing charges are Concorde's former chief engineer Jacques Herubel, and Henri Perrier, a former head of the Concorde division at Aerospatiale - now part of the aerospace company EADS.
Claude Frantzen, a former member of France's civil aviation watchdog, is the fifth individual defendant.
Manslaughter charges can carry penalties of up to five years in prison and a 75,000 euro ($104,000) fine - but correspondents say that in the case of guilty verdicts, suspended prison sentences are more likely in this case.
Only some of the victims' families will be represented at the hearings, as most took compensation from Air France after the crash in return for not taking legal action.
Stephane Gicquel of Fenvac, a French federation representing the interests of the families of crew members, said relatives would watch the trial with great interest.
"This tragedy is part of their personal history and of their family history," Mr Gicquel told the BBC.
The trial, in Pontoise, near Paris, is expected to last four months.
The disaster was the only crash ever to involve a Concorde supersonic airliner.
Air France and British Airways retired their Concorde fleets in 2003.