The president of a California firm was sentenced yesterday to three years in prison and fined $750,000 after pleading guilty to falsifying tests on millions of bolts his company produced for some of the nation's most sophisticated warplanes, including the B-1 bomber and the F-14 fighter.

The sentence, considered unusually severe for an officer of a defense contracting firm, was levied in U.S. District Court in Los Angeles against Norman McHaffie for his role in what prosecutors described as the longest-running defense fraud uncovered in recent history.

McHaffie, president of McHaffie Inc., pleaded guilty to charges that he submitted fake documents to the military over a 10-year period beginning in 1979, certifying that the engine bolts met government standards even though they had never been tested. In an effort to hide the fraud from government investigators, McHaffie and a company employee tried to destroy incriminating documents by tossing them into a trash dumpster after the government probe began, according to Assistant U.S. Attorney Stephen A. Mansfield.

Two other employees of the company also were sentenced to jail after pleading guilty to charges involved with the fraud scheme: quality control supervisor James Hicks was sentenced to 18 months in jail and production shop floor manager William R. Whitham was ordered to serve 20 weekends in jail and perform 150 hours of community service.

McHaffie Inc. was also fined $750,000.

Vincent Marella, the attorney who represented McHaffie, said that even though his client pleaded guilty to the charges, McHaffie was unaware of the extent of the fraud because he was frequently absent from the company and left it in the day-to-day control of other employees.

Marella also said that neither McHaffie nor his company, which is now out of business, have the funds to pay the combined $1.5 million in fines.

The military is continuing its search for millions of bolts purchased from McHaffie through almost 4,000 contracts, according to Mansfield.

"Some bolts did make their way into airplanes," Mansfield said. "I don't think anyone can say with absolute certainty where all the bolts are."

Mansfield said military officials believe some of the bolts are in planes now in use, but said the military has not linked any failures of aircraft engines to the McHaffie bolts.

Mansfield added that a bolt failure in an aircraft engine could cause the airplane to crash.

In addition to falsely certifying tests that had never been conducted, the company was accused of falsifying results to indicate that bolts passed tests when they had failed, according to court documents.

The McHaffie bolts have been used in aircraft including the Air Force's B-1 bomber, F-16 fighter and A-7 Corsair II attack plane; the Navy and Marine Corps F/A-18 Hornet attack fighter, and the Navy's carrier-based F-14 Tomcat fighter.