The Army, conceding to critics who branded the Bradley Fighting Vehicle unsafe, will install new protective devices that will add more than 10 percent to the cost of each machine and increase its weight by up to one-third.

Although Army officials say the improvements will enhance the armored vehicle's chances of battlefield survival by 50 percent, the General Accounting Office, Congress' investigating agency, warned that the Bradley still has serious deficiencies that could jeopardize crews.

The improvements are expected to cost at least $113,000 per vehicle and to increase the weight of some battlefield models by 7.5 tons -- to 32.5 tons.

The $10.2 billion Bradley system, a cornerstone of the Army's modernization program, has been one of the most controversial new weapons systems this decade. Critics charged that the Bradley -- a combination personnel carrier and tank -- is poorly designed to survive combat and that the Army did not conduct realistic tests before it was sent to the field.

Army officials, appearing yesterday before the House Armed Services subcommittee on procurement and military nuclear systems, publicly revealed for the first time the results of live-fire tests on Bradley vehicles, and plans to correct the design flaws.

Army live-fire tests, conducted under orders from Congress, revealed that the Bradley's shell did not adequately protect the mannequin troops inside from some enemy fire and that if munitions penetrated the vehicle's inside storage compartments for ammunition and TOW missiles, that could "cause a complete loss of the vehicle and its crew," according to reports presented to the committee.

As a result, the Army plans to improve new Bradley vehicles and retrofit about half of the 3,361 vehicles now in the field with additional armor, interior linings to help protect the crew from flying munitions fragments and new storage tanks for ammunition and TOW missiles. The other half of the vehicles now in the field will not be retrofitted, an Army spokesman said.

The cost of the improvements for the life of the Bradley program could total $1.6 billion, Army officials told the subcommittee. The Army has received about half of the 6,882 vehicles it plans to buy from California-based FMC Corp.

The Army is scheduled to add some of the improvements to new Bradleys next July, but said it could be years before vehicles already in the field are retrofitted.

Despite the Army's improvements, congressional investigators say the Bradley continues to be plagued by other serious problems and that some of the Army's fixes will cause additional problems.

An Army spokesman said the additional weight will leave the Bradley slower, less agile and a bigger fuel-guzzler. An Army report also said the weight will impede the Bradley's ability to climb river banks.

But Army officials also noted that the service already had planned to increase the Bradley's engine from 500 to 600 horsepower, a change they said will offset the added weight.

The GAO told the committee yesterday that the Army still has not resolved all of the problems with the vehicle's transmission, electrical systems, integrated sight unit -- which is supposed to allow the crew to fire its weapons under virtually any environmental conditions -- and its ability to swim.

Bradley crews also told the GAO that the heaters in the earlier models fail regularly and they frequently have had to wrap themselves in sleeping bags to stay warm while operating the vehicles, Mark E. Gebicke said.

Congress ordered the live-fire tests after the House Energy and Commerce Committee's panel on oversight and investigations and the Armed Services Committee confirmed major battlefield vulnerabilities in the Bradley.

The Defense Department's chief weapons testing official, John E. Krings, told the committee that in the new tests the simulated crews survived the attacks more frequently than anticipated because they usually were not inside the vehicles during the heat of battle.

The drivers, however, aren't as fortunate. "Bradley drivers didn't fare too well because they're always in it," said Krings.

THE BRADLEY FIGHTING VEHICLE

STATISTICS ---------------------------------------

Length: 21 feet 2 inches Height: 9 feet 9 inches Weight, combat loaded: 25 tons Weight after proposed improvements: 32.5 tons

Armament: 25-mm gun TOW missile launcher 7.62-mm machine gun

Personnel capacity: 10 people Fuel tank capacity: 175 gallons Speed on land: 41 mph Number delivered to Army: 3,361 Total planned for purchase: 6,882 Current cost per vehicle: $1.33* million Total Program Cost: $10.2 billion

PRAISE FROM THE PAST -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- --

"I think if any of you went into combat in this {vehicle} . . . or sent your son in, you'd sure rather go in this one than any other fighting vehicle on the battlefield today. We think, when you balance everything -- the weapons with the agility, with the size, with the weight -- we've got a good vehicle . . . . I can assure you that the leadership of the Army would not buy something and send it out there if it was a deathtrap."

Lt. Gen. Louis C. Wagner Jr., Dec. 11, 1985

"This is the best thing for the infantrymen since bubble gum."

Sgt. George Blount, a Bradley commander, comments reported Jan. 28, 1986

"With the Bradley, we have the advantage."

Col. Smythe Wood, a brigade commander, comments reported Jan. 28, 1986

"There is not a vehicle available today, or in design, which could replace the Bradley . . . . {The Bradley} provides significant improvement in agility, firepower and survivability over its predecessor . . . . The Bradley was not intended to withstand these kinds of {missiles or high-velocity artillery fire} . . . nor is any armored personnel carrier or fighting vehicle of any armed force. In fact, heavy armor in such a circumstance could be in harm's way."

Gen. John Wickham Jr., Army chief of staff, and John O. Marsh Jr., Army secretary, May 21, 1986

"It is a revolutionary improvement in our capability."

Col. John Fuller, commander of the 29th Regiment, comments reported Dec. 13

*Department of Defense total acquisition cost for fiscal year 1987.

SOURCE: FMC Corporation