The trial marks the first time criminal charges have ever been filed in a commercial jet crash, and the jury must determine whether human error or criminal conduct caused the accident.
SabreTech, ValuJet's maintenance contractor, and two former employees are charged with conspiracy and lying on repair records leading up to the 1996 crash in the Everglades.
"Fundamentally, this is a case about lying. One of the lies turned out to be about something very important," Assistant U.S. Attorney Caroline Miller said Wednesday. "SabreTech's urge to have its business done overtook other considerations, including safety considerations."
She singled out mechanic Eugene Florence, who signed a work card stating he had placed shipping caps on explosive-tipped oxygen generators. He later admitted no caps were installed.
Jane Moscowitz, a defense attorney for Florence, said mistakes were made but the crash of the DC-9 was a tragedy, not a crime. She described Florence as a "good man" working in good faith to secure the generators.
A total of 144 generators delivered by SabreTech to the ill-fated flight were blamed by crash investigators for fueling a cargo fire that spread into the passenger cabin during the 11-minute flight.
Moscowitz highlighted 45 mechanical problems reported on the 27-year-old jet in its final five months, including five problems with the autopilot the week of the crash.
Electrical problems "festered in that plane. It was an accident waiting to happen," she said. "I don't think [generators] started the fire."
Daniel Gonzalez, a vice president of maintenance, shares the conspiracy charge with the company and Florence. He also faces a false-statement count over a work card he signed on another jet in 1995.
If convicted, Florence faces up to 15 years in prison, while Gonzalez faces up to 10 years.
SabreTech also faces 17 counts of hazardous materials violations and could face up to $5.8 million in fines plus restitution to victims' families. The Phoenix-based subsidiary of Sabreliner Corp. was driven out of business after the crash.
ValuJet, which has changed its name to AirTran, and SabreTech have settled most lawsuits brought by victims' families, but a handful are set for civil trial.
SabreTech also has been charged in state court with murder and manslaughter.