The Army is moving ahead with a controversial plan to store more than half of its total combat equipment in Europe where it would be in range of Soviet bombers and missiles.

Backers of the plan contend that getting the tanks, guns, missiles and helicopters into Europe before any war starts is the best way to ensure that American troops based in the United States could go into battle in a hurry.

Critics counter that this new plan, which would strip home-based divisions of much their weapons, amounts to putting too many eggs in one basket at a time when war is most likely to occur outside of Europe.

Besides the strategic concerns, Robert W. Komer, Defense Secretary Harold Brown's Atlantic Treaty Organization adviser, told a private meeting of the Atlantic Council last week that the new plan to ship enough weapons to Europe to arm three divisions will be so costly that Congress may balk at providing the money, according to sources who heard his speech.

The council is nongovernment citizens group dedicated to strengthening the Western alliance. Komer, according to those who heard his talk, urged council members to express their support of this American move to beef up NATO.

Although an Army spokesman said yesterday he had been unable to get money figure released, a secret Pentagon document estimates that it would cost slightly over $2 billion to store the equipment for three divisions in Europe.

Instead of buying an extra set of equipment for three divisions, the Army plans to take the weaponry from its 10 divisions based in the United States. This would leave those divisions with 70 percent of the combat equipment they normally have for training.

"If we're having trouble training our troops when the division has 100 percent of its equipment," asked one Army critic of the plan, "how are we going to do the job with only 70 percent of the equipment?"

More worrisome, according to critics of storing so much equipment in one place, is the lessened ability the Army would have to respond to threats outside of Europe once the bulk of its arms is positioned there.

The Army already has 5 2/3 divisions, plus their equipment, on the ground in Europe to fight a NATO war. On top of that, the Pentagon has stored in Europe enough combat equipment for two divisions based in the United States.

Once the equipment for an additional three stateside divisions is in Europe, the Army will have the arms for a total of 10 2/3 divisions on the ground there. Since the Army has a total of 16 2/3 divisions, the bulk of its total combat equipment is destined to be concentrated in Europe. Stateside troops would fly to Europe and pick up their weaponry there in an emergency.

One outspoken critic of this strategy is retired Rear Adm. George H. Miller, former Navy director of strategic planning. He said storing the arms in Europe where they could be easily spotted and targeted, plus concentrating troops on what should be the forward picket line for alerting forces to the rear, "enables the Soviets to deal with them in their own time and in their own way."

Gen. Alexander M. Haig, NATO commander, told the Senate Armed Services Committee, earlier this year that studies have shown that the period of "greatest danger, greatest vulnerability" for defending NATO forces would be "a few days to a couple of weeks" after an attack was launched against them.

The stepped-up effort to pre-position more equipment in Europe is TANO etaoibgkqjj part of a campaign to prepare NATO forces to respond quickly to a Warsaw Pact thrust.