If the coaches and general managers have their way, it will be bombs away in the NBA next season.

Both groups, meeting separately yesterday, overwhelmingly approved a proposed rule change that would bring the three-point field goal to the league next season. The action was taken on the final day of their two-day meeting at the Mayflower Hotel.

The coaches voted 15-5 to approve; the general managers voted 15-7.

Both groups said the move was designed to open up the game and to add excitement, and they expect the league owners to approve the three-point proposal at their meeting next week at Amelia Island Plantation in Florida.

"I don't think it's a gimmick, but will be a legitimate part of the game," said Washington Bullet General Manager Bob Ferry. "It adds another way to win or lose a game and the more of those there are, the more excitement you have."

The recommendations of the coaches and general managers now will go to the 11-member rules and competition committee, which will report directly to the owners.

"We feel we are the most knowledgeable people in professional basketball and our opinions aren't given lightly, so it would certainly be our hope that our recommendations are well received," said Portland Coach Jack Ramsay, president of the NBA Coaches Association.

Neither the coaches nor general maanagers made it clear at what distance they wanted the three-point field-goal line. But they are leaning toward a plan similar to that in the old ABA, in which the three-point shot ranged from 22 feet in the corners to 23 feet 9 inches at the top of the key.

Ramsay said that the coaches who had experience with the three-point goal in the ABA indicated that it would "open up the game and eliminate some of the congestion in the basket area because defenses would have to expand to cover more of the court."

The premier long shooter in the league now is probably Brian Winters of the Milwaukee Bucks. Others are Lloyd Free of San Diego, Rick Barry and Rudy Tomjanovich of Houston, Kevin Grevey of Washington and Fred (Downtown) Brown of Seattle.

The coaches and general managers also voted overwhelmingly against legalizing the zone defense, but did vote to recommend two other rule changes - a possible four-point play if a player is fouled while making a three-point field goal, and giving the offensive team a maximum of 10 seconds to get the ball into the front court.

As the 10-second rule stands, if the ball is knocked out of bounds with fewer than fivew of the allotted 10 seconds left, the offensive team gets five full seconds to get it into the front court. The new rule would say that if the ball is knocked out of bounds with one second of the 10 remaining, the offensive team has only that one second to get the ball out of the back court.

The coaches also recommended that a three-foot line be painted on the court, behind which the defender has to stand while the offense inbounds the ball. But the general managers voted against that recommendation.

The coaches also voted to continue using three officials for all games.

In other business, the general managers agreed to create a committee to study the possibility of the NBA affilitating with the newly formed minor league, the United Basketball Association.

Phoenix General Manasger Jerry Colangelo, who chaired the general managers' meeting, said the NBA "is interested in the proposal, but there are so many ramifications that have to be considered. We are favorably inclined toward doing something, but we need time to study it."

This is the first time the league has had its coaches and general managers meet separately from the owners. The format was designed to give them more time to go over proposals before making recommendations to the owners.

The coaches also set up a committee of San Diego's Gene Shue, Kansas City's Cotton Fitzsimmons and Boston's Bill Fitch to meet with Norm Drucker, supervisor of officials, to clarify the interpretation of the zone defense.

Another committee of Kevin Loughery of New Jersey, Hubie Brown of Atlanta and John MacLeod of Phoenix was set up to offer suggestions "and their knowledge to help television better its presentation of the NBA."

No trades were made at the meetings, but there was plenty of preliminary work done. Two people who did a lot of huddling were Ferry and Detroit Coach Dick Vitale . . . The Bullets are trying to get a first-rate guard, namely free-agent Kevin Porter, and would also like to improve their draft position, which is 22nd.

The Bullets in which other teams are interested are Mitch Kupchak and Greg Ballard, the two players Ferry Does not wan to give up . . .