U.S. Judge J. Skelly Wright has asked the District of Columbia School Board to tell him in detail what problems there may have been in carrying out his 1971 equal-spending decree, and reminded the board that any changes it proposes must be in line with "the spirit of that order."

Wright made his request after lawyers for the American Civil Liberties Union strongly opposed the school board's motion, filed in late June, to vacate the 1971 decree.

The board said it wants to be free of court restrictions so it can carry out its own plan to equalize basic programs and staffing - rather than teachers' salaries - in all city schools.

But the ACLU lawyers charged that the board's plan would permit such "vast variations" in pupil-teacher ratios and per-pupil spending that it amounts to "abandoning" the equalization decree.

Under the 1971 order, per-pupil spending on teachers' salaries must be within 5 per cent of the citywide average at every one of the District's 129 elementary schools.

School officials have complained repeatedly that the order led to wide differences in school programs because teachers' salaries vary widely depending on seniority. But their court papers filed in June deliberately took a "positive approach," board counsel David Splitt said and contained no discussion of the problems the decree has created.

The ACLU lawyers said that because the school board presented no charges or evidence that the 1971 order had been "burdensome, . . . harsh, or even inconvenient," there was "no basis" for dropping the equal-spending requirement.

In his new order, Wright asked the board to spell out in detail what its problems have been and also to answer the ACLU's other arguments.

Wright issued his equal-spending decree in May, 1971, in a case brought by Julius Hobson Sr., a former school board member and city councilman who died in March.

The ACLU handled Hobson's case then and is continuing to litigate it with volunteer attorneys from two major law firms. Peter F. Rousselot, of Hogan and Hartson, and S. William Livington Jr., of Covington and Burling.

Both lawyers live in the Virginia suburbs, but they have filed court papers that name Naomi Mitchell, of 1305 Locust Rd. NW, as a substitute plaintiff in the case, which is a class-action suit on behalf on black children in D.C. public schools.

Judge Wright, who sits on the U.S. Court of Appeals, has handled the case on special assignment as a U.S. District Court trial judge.

Ralph J. Temple, legal director of the Washington area ACLU, said the organization decided to oppose the school board's motion to vacate the decree because the board's new plan "doesn't amount to a whole lot more than an expression of good intentions, and after so many years that just isn't enough."

The board's plan would require all schools at each level to provide the same "basic curriculum" and have the same ratio of pupils to instructional staff - including teachers, principals, counselors, librarians, aides, and clerks - within 5 per cent of the city-wide average.

The ACLU lawyers said the school board would carry out its new curriculum without any changes in the 1971 decree. They said the crux of Wright's 1971 order was that experienced teachers (with high salaries) be distributed uniformly or that schools with mostly young teachers have "some offsetting benefits."

Any distribution formula like the board's that equates aides with teachers would permit wide inequalities, the ACLU lawyers said, although they added that they were willing to try to work with the board to draw up a new equalization procedure "which permits greater flexibility."