A key member of the Smithsonian's board of regents yesterday said the board and its executive committee did not encourage Secretary Robert McC. Adams to fire his second in command, Dean Anderson. He also said the dismissal was unrelated to ongoing discussions about management restructuring at the institution. "That has nothing to do with this episode," he said.

David Acheson, who heads the three-member executive committee of the board of regents, portrayed the dismissal late last week as the result of a personality clash rather than a response to financial difficulties at the institution. He said he expects the Smithsonian to face "presumably severe cuts" but said those cuts are just "a short-term inconvenience" that will "put a crimp in a lot of programs for the coming fiscal year and perhaps the next fiscal year and perhaps the next after that."

The decision to fire Anderson was made without involvement by the 17-member board of regents as a group, he said. "The regents have always made only one appointment and that is the secretary," he said. "We have not instructed Adams to fire him. We haven't even met recently enough to do that. We have never interfered in management appointments... . This matter wasn't even in the air at the last regent's meeting."

But he said the three-member executive committee was aware that Adams intended to dismiss Anderson. Other members of the executive committee include Chief Justice William Rehnquist and Samuel Johnson, chief executive officer of S.C. Johnson & Son Inc. in Racine, Wis. "Of course the executive committee discussed the matter, and we support Bob," Acheson said. "We picked him and we support him."

Acheson declined to go into detail about the reasons for Anderson's dismissal. "I don't want to trample on people's sense of proprietary information," he said. But he added, "There's not an issue here. There's a question of working relationships."

He added, "Washington is full of number ones and number twos who have got to get along with each other to be effective... . When that doesn't happen, at some point, they come to an understanding that they have to make a change. That's how it was."

He said the dismissal does not reflect poorly on Anderson, who leaves his post with "a lot of goodwill and admiration." Anderson will become an adviser to Adams when his resignation becomes effective at the beginning of September. "Changes aren't always accompanied by recriminations," Acheson said. "In many cases, people who like each other and really want to do the right thing just don't work it out well."

Acheson said he couldn't explain the timing of the decision, which comes almost exactly five years after Adams chose Anderson to be undersecretary. "It was really Bob Adams's decision and the timing was his timing... . Why it didn't happen sooner, why not later, I don't know," he said. "I think what happens is a recognition of a situation grows and finally gets to a point where the principals do something about it."

Acheson said the firing of Anderson, who was at the Smithsonian for 17 years, is "not a big deal."

The extent of the institution's financial problems was clouded yesterday by conflicting signals. Rep. Sidney Yates (D-Ill.), chairman of the subcommittee that handles the institution's appropriation, said he did not believe the Smithsonian faces a crisis and observed that the recommended fiscal 1991 appropriation of $313 million exceeds its request by several million dollars.

But National Zoo Director Michael Robinson bolstered Adams's contention that money problems are extremely serious. In a statement, Robinson said the zoo has already "suffered drastically" from money shortages and warned that further cuts could "severely affect the care of our marvelous collection of animals and the safety of visitors to our 163-acre park."

While some sources at the Smithsonian have suggested that Anderson took a fall for Adams in the face of a financial crisis, Acheson said the board of regents supports the secretary. "We think Bob is a good secretary. We like his emphasis on education and research and we'll continue to support him," he said.

He dismissed complaints from some observers that Adams has not been sufficiently involved in day-to-day management. "Bob's a very hands-on guy," he said. "Bob picks his projects. His style is to get deeply involved with his highest priorities." As an example, Acheson cited the planned National Museum of the American Indian and a planned -- but now jeopardized -- extension of the National Air & Space Museum.

"Inevitably, a secondary or tertiary priority for him is going to be a primary priority for somebody in the institution and that somebody ... gets frustrated," Acheson said. "They get together and they talk with each other and they have this council of bureau directors and they gossip among themselves. Pretty soon ... you get the impression that what those guys are concerned about is terribly important and Bob isn't paying much attention to them. But here's a guy who has brought to fruition {some} of the most important things that have happened at the institution."

Acheson emphasized that the regents do not get involved in management decisions. "The role of the regents and executive committee is essentially what you'd expect of the trustees of a university," he said. "That is, to stay in consultation with senior management and make recommendations from time to time ... provide a set of ears for problems to be bounced off and see that the place is being run in a way that satisfies the regents that the institution's objectives are being met." He said the regents would not get involved in management because "pretty soon you are responsible for a lot of things that you don't have time to study and understand."

He said that many at the institution are overreacting to financial problems. "After 25 years we are now facing the need to be careful and probably to reduce our objectives. Those people who have no sense of history now panic... . It's silly to panic. It's childish. It isn't grown up." He said people should "remember that the earth's horizon is larger than that of a billiard ball."