It is a familiar rite of spring in the federal city, the biennial exodus to Le Salon de L'Aeronautique et de L'Espace, known in these parts as the Paris Air Show.

This season, the story lies more in who and what will not be on hand for the 37th edition of the world's largest aerospace trade fair, Friday through June 21, at Le Bourget Airport.

Members of the House Science, Space and Technology Committee, for example, have traditionally been loyal attendees. This year, however, they will be here marking up a space bill and otherwise working hard, aides say.

About 30 committee members had planned to go, according to Capitol Hill sources, but they received word from the Pentagon that the military plane they thought they had reserved was not available. Rather than accept a much smaller plane offered by the Air Force, committee Chairman Robert A. Roe (D-N.J.) decided not to take an official delegation, according to his spokesman, Robert W. Maitlin.

There was speculation that the committee lost its plane -- for the first time in anyone's memory -- because of a continuing flap between its members and Defense Secretary Caspar W. Weinberger over the administration's proposed space station. Maitlin, however, said there is no evidence of this and an Air Force spokesman, Maj. Jan Dalby, said he was unaware of any such connection. The Air Force provided what planes it had available to various committees as requests came in, he said.

Select members of the defense subcommittees of the House and Senate Appropriations committees, as well as the Senate Armed Services Committee, have been provided planes, Dalby said.

In the not-going category are costly exhibition models of projects such as the space station that the National Aeronautics and Space Administration usually ships over. In a cost-cutting move, the agency is sending instead an audio-visual presentation called "Flight Path to the Future," which will highlight long-range projects such as the space plane. After its showing at the U.S. pavilion in Paris, the film will be shown at the popular experimental aircraft fly-in at Oshkosh, Wis., and other events, according to James Funkhouser of NASA's special events branch. "We can amortize the investment," he noted.

NASA Administrator James C. Fletcher is leading a delegation of eight top officials, five staff members and four astronauts, including two from the crew of the next shuttle flight, scheduled for about a year from now.

In general, the country is sending fewer aircraft for demonstration than in the past, according to Donald Creed, a spokesman for the Commerce Department, which sponsors the USA Pavilion. "Flight demonstrations are not as popular, as fewer new programs are being launched," he said. "The new emphasis is in the display of new electronic products."

The centerpiece of the U.S. military exhibit will be the controversial B1B bomber, which has been criticized for not living up to its mission requirements. The Air Force hopes that sending one to the show "demonstrates to our allies and to any potential adversary the near-term readiness of this operational weapons system and our country's firm commitment to a strong defense," said Air Force Secretary Edward C. Aldridge Jr.

However, after its landing at Le Bourget, the sleek, dark green plane will remain stationary on the tarmac, with tight security measures to keep the public at a polite distance, officials said. This is to protect sensitive electronics and other equipment inside.

Estimated cost of sending the plane to the air show is $194,800, including fuel and logistical support, officials said.

Aldridge will lead a contingent of 45 Air Force officials and crew members from here, plus 20 Air Force officers and security police stationed in Europe.

The Voyager aircraft, which made a nonstop flight around the world on one tank of gas last December, will be on display in a covered stand, with pilots Richard Rutan and Jeana Yeager in attendance.

Sen. Strom Thurmond (R-S.C.) is President Reagan's official representative at the show this year. "He has in mind several meetings with many corporations and he will try to encourage them to locate plants in South Carolina," said his press secretary, Mark Gooden. "It is a marvelous opportunity."

Sen. Ted Stevens (R-Alaska), who always goes, "believes that significant exports do result from the air show, particularly in spare parts, electronics and landing gear," said an aide.

Sen. Tom Harkin (D-Iowa) is going to the air show on the way to a day of meetings on agriculture policy in Strasbourg because, as a former Navy pilot and now a private pilot, "he has an interest in aviation policy," said an aide. The industry "represents a large amount of exports and the U.S. is losing out, we are losing our edge," the aide said.

Contingents from the Federal Aviation Administration, the National Transportation Safety Board and Transportation Department also will attend the show, officials said.

Space is expected to be a dominant theme, with the Soviets, Europeans, Japanese and representatives of other nations competing to market launch services. From the United States, the makers of Titans and Deltas will be there to compete for commercial customers under a new Reagan policy of "privatization. "Staff researcher Lee Kennedy contributed to this report.