The Smithsonian Institution yesterday opposed a bill introduced by Sen. Barry Goldwater (R-Ariz.) that would authorize funds to construct a museum for historic airplanes and spacecraft at Dulles International Airport. The new facility would be administered by the National Air and Space Museum.

Testifying yesterday before the Senate Committee on Rules and Administration, Smithsonian Secretary Robert McCormick Adams said the institution has more immediate legislative priorities. The Smithsonian does support planning appropriations, however.

But Goldwater, who testified yesterday, wants to "strike while the griddle's hot," his legislative assistant Terry Emerson said later. In 1976, Goldwater was instrumental in pushing funds through Congress for the National Air and Space Museum.

The bill Goldwater introduced in June calls for $42.6 million in government appropriations in fiscal 1989 and beyond, contingent on an equal amount in matching donations from the private sector.

Adams questioned whether the institution should, or could, raise that much money. In a letter to committee chairman Sen. Charles McC. Mathias (R-Md.), Adams said federal appropriations should cover the full cost of the project. The institution has more pressing fund-raising commitments and its Board of Regents has not had time to consider an effort of this magnitude, Margaret Hird, his assistant, said after the hearing.

Along with Goldwater, Sens. John Glenn (D-Ohio) and Paul Trible (R-Va.), cosponsors of the bill, voiced their support at yesterday's meeting.

"Today's students will go on to be tomorrow's technological leaders," Glenn said. "They will be the engineers, scientists and physicists needed to meet the challenges of our highly technical society . . . A facility like the one proposed in this legislation will serve to spark interest among those people who will be tomorrow's aviation pioneers."

Although Goldwater is on the Smithsonian's Board of Regents, he is pushing the issue now, rather than waiting. "It's just an interest in priorities," Emerson said, asserting that politicians have a greater sense than do Smithsonian officials of the interest in technology-related museums.

"Later they'll come in once they see the overwhelming interest in it," he said.

"Once enabling legislation is enacted," Goldwater said, "I believe numerous private individuals and firms will begin a major fund-raising campaign that will produce enough matching monies to get the first construction going by fiscal year 1989."

Robert Allnut, vice president of the Air and Space Heritage Council, told the committee that his organization can help raise the funds.

"They say so," responded the Smithsonian's Hird later. "We have seen no documentation of how they could go about all of that."

The Smithsonian's Board of Regents initially approved the concept for the air museum in September 1983. Officials cited insufficient space at the National Air and Space Museum and the difficulty of transporting large aircraft and spacecraft to the Mall building as key reasons for expansion.

Under the plan, the Federal Aviation Administration would lease 100 acres of its land at Dulles without compensation. Proximity to a runway is essential, since many of the aircraft and spacecraft, such as the Concorde and space shuttle, are too large to be transported on roads.

But the air museum issue was low on the Smithsonian's legislative agenda yesterday, as Adams called for the committee's support for the following:

*$4.5 million to build a base camp for the Fred Lawrence Whipple Observatory in Arizona to provide operational and logistical support for observing activities on Mount Hopkins.

*$11.1 million for four projects in tropical biology, all based in Panama: $3.9 million to consolidate services at the Smithsonian's Tivoli site in Panama City; $2.8 million for a new laboratory for Barro Colorado Island; $3.5 million for a laboratory and sewage system at Galeta on Panama's Atlantic Coast; and $900,000 for creating a central maintenance facility.

*$11.5 million to construct a new wing for the Smithsonian's Cooper-Hewitt Museum in New York, the only museum in the United States devoted exclusively to the study and exhibition of historical and contemporary design.

*Reauthorization of the National Museum Act, which provides $793,000 to the institution for use in helping other museums improve conservation techniques through training programs, research and publications. Although Congress has appropriated the funds, the House did not pass the reauthorization act in 1981 and 1983. Hird said the institution wants Congress to make a long-term commitment, as it has in past decades.

The committee will rule on the proposed legislation in September.