The employees say Interactive Flight Technologies' entertainment system produced excessive heat, which worried them. They contacted USA TODAY after it published an investigative report on the system on Feb. 17.

The Canadian Transportation Safety Board is scheduled to release its report of the Swissair accident today, 41/2 years after the crash. Swissair Flight 111, a McDonnell Douglas MD-11 flying from New York, crashed near Nova Scotia, killing 229 people.

Delta was a Swissair Code-Sharing Partner on the route-but didn't have the IFEN

Canadian investigators found that entertainment system wires and other wires had short-circuited, and an onboard fire had occurred. The Federal Aviation Administration subsequently banned the system from airliners.

It's not clear whether the system's heat problem had any bearing on the accident. But what the employees say may support the FAA's internal post-crash review that found flaws in the system's design and installation, as well as its certification by an FAA-approved contractor.

Dean Lilja, a former IFT mechanical engineer, says that he and other engineers repeatedly expressed their concern that the system generated too much heat.

"It was always an issue, and it was never dealt with," he says.

A reconstructed aircon duct - aircon circulation would have helped spread the fire in the flammable (now banned) mylar thermal-acoustic blanket linings

Lilja, who worked for IFT from December 1994 to August 1996, says he raised the issue with IFT's then-chief executive officer Michail Itkis. "Michail would say, 'It's not a big deal,' " Lilja says.

When one of the system's components caught fire during a test flight, Lilja says, a manager told him not to say anything.

Neither Itkis nor his father, IFT founder Yuri Itkis, returned phone calls seeking comment. IFT is no longer operating.

Fred Barber, who began working as IFT's quality assurance manager in fall 1995, says that each entertainment system box located under a passenger seat was excessively hot. He feared passengers would burn themselves.

The boxes "got so hot, you could fry an egg on them," he says. "I complained about the heat problem in several meetings but was told not to worry."

After the Swissair crash, Lilja says that some IFT employees were concerned that the entertainment system was responsible. One former IFT official, he says, told them to keep quiet.

Barber says he doesn't believe the IFT system was the cause of the accident, because its electrical components were protected by circuit-breaker systems.

Since USA TODAY's story, the General Accounting Office, the investigative arm of Congress, has begun examining the FAA's use of thousands of private companies to inspect and certify airlines' planes and alterations to them.

The Department of Transportation's Inspector General is considering an investigation.