The Army fired, handcuffed and removed from office a veteran engineer for threatening to disclose that many troop-carrying helicopters primed for war in Saudi Arabia lack protection against Iraqi heat-seeking missiles.

Calvin J. Weber, a 16-year Army civilian employee, was fired last week for seeking information about the vulnerabilities of Army helicopters now in Saudi Arabia and "intimating" he would make it public, the Army said yesterday.

"Information regarding equipment vulnerabilities, especially during the pendency {sic} of Operation Desert Shield, is very sensitive, and its disclosure could be highly detrimental to the security of the United States," Col. Thomas E. Reinkober told Weber in a one-page memo ordering him to leave his office at the Army Aviation Systems Command in St. Louis.

Weber, 48, went public with his story yesterday following his dismissal Thursday, when federal police led him from his office in handcuffs after he refused to leave voluntarily.

Weber said roughly 800 of the Army's 1,062 UH-60 Blackhawk helicopters lack infrared suppressors, which are muffler-like devices installed over both of the Blackhawk's engines. They are designed to cool the exhaust before it leaves the engines and hide the turbine blades from heat-seeking missiles.

The Army has about 300 Blackhawks in Saudi Arabia -- more than any other type of helicopter -- to ferry troops to the front and to evacuate casualties from the battlefield. Weber estimates about 200 of them lack the suppressors.

While the Army declined to say how many of the UH-60s now in Saudi Arabia lack suppressors, Blackhawks recently photographed there did not have them.

Without suppressors, the helicopters are vulnerable to Iraq's arsenal of Soviet-made anti-aircraft missiles that home in on the engine's hot exhaust, according to Pentagon and industry officials.

Army officials declined to discuss the subject. "Anything that deals with the limitations and capabilities of systems assigned to Saudi Arabia cannot be discussed," said spokesman Bob Hunt of the Aviation Systems Command.

A 1985 Pentagon study concluded that 90 percent of the aircraft downed in combat in the previous 10 years were destroyed by heat-seeking missiles. Most of the losses were Soviet aircraft downed by Afghan rebels equipped with portable, U.S.-made, Stinger heat-seeking missiles.

The $7 million Blackhawks, which carry 11 troops and a crew of three, were supposed to have suppressors installed as they were built. But the Army scrapped the original suppressor design because it was heavy, prone to cracks and worked only when the helicopter was cruising, Weber said. Consequently, the roughly 800 UH-60s delivered to the Army from 1979 to 1987 lack suppressors.

Weber was one of a handful of Army engineers working to make aircraft less vulnerable to missiles. He said he is challenging his firing and will plead not guilty to the disorderly conduct charge filed against him for refusing to leave voluntarily.