In that race, the payoff for the triple was so unusually low as to create suspicions among stewards and board investigators.

That sudden loss of power may have contributed to the crash, said John Hammerschmidt, a board investigator.

The planes are often operated by companies that are not authorized or qualified to do so, board investigators said.

The effect was to create a 5-inch "ski jump" that made the train jump the tracks, board investigators said.

At one point, police detectives even used listening devices to monitor the activities of board investigators, according to a police memo.

But, the agency official said, board investigators were skilled generalists.

And board investigators discovered other examples of USAir planes taking off without enough fuel.

When questioned by board investigators as to who was responsible for tracking the helicopters, Tracy said, "I cannot tell you that.

When board investigators asked Mr. Goldstein about the cafeteria contract, at first he could not place the company's name.

In a windowless conference room at the safety board's headquarters, board investigators showed diagrams and charts.