The Fairfax County Board of Supervisors yesterday reaffirmed its opposition to a proposed plan to scatter National Airport flights over the Washington area, even on a trial basis.

The board, by a 6-to-3 vote, rejected a proposal to ask the Commission of Governments and the Federal Aviation Administration to hold public hearings on the scatter plan.

Although the board has been on record since 1981 against the controversial plan to shift some flight paths currently over Arlington and Alexandria to the air space over parts of Fairfax County, some supervisors said they believed the FAA should hold hearings because additional information about the plan is available.

But the proposal for hearings, by Board Chairman John F. Herrity, met with strong opposition from other board members. Only Supervisors Sandra Duckworth (D-Mount Vernon) and Nancy Falk (R-Dranesville), whose districts stand to benefit from the scatter plan, voted to ask for the hearings.

Martha V. Pennino (D-Centreville) said the plan is a "very unfair thing" in that it puts an "unfair burden on the people in Fairfax County suburbs."

She added that "the people who live along the Potomac made a conscious decision to live there." She said they chose to live in the flight paths, perhaps for reasons of proximity to Washington. "Many people made the decision to move further out--and take the inconvenience of commuting and the traffic jams--in favor of living beyond the flight paths," she said.

Marie B. Travesky (R-Springfield) also was outspoken against the hearing proposal, recalling that the board in 1981 called it "the misery-loves-company plan."