LONG BEFORE the District of Columbia turned to Floretta Dukes McKenzie to take on the heavy duty of overseeing this city's school system, insiders would mention her name every time the job came open. And back in those horrendously tumultuous days, the job came open with alarming frequency. By the time Mrs. McKenzie took over in 1981, the school boards had worked their way through -- or worked over -- eight superintendents or acting superintendents in a dozen years. That included one notable run of five years by Vincent E. Reed (who now serves this newspaper), in which he established order and a return to the basics in classroom instruction -- a foundation on which Mrs. McKenzie would build with remarkable results. Now, after more than six years of invaluable public service, Mrs. McKenzie has announced that she is leaving, and a grateful city must scramble to find a worthy successor.

We are not alone in wishing Mrs. McKenzie would stay on, continuing an era of stability, pride and classroom accomplishment that she maintained and strengthened. At least her transition to a national contribution to public education will not sever her ties to this city -- a fact that should not be lost when the school board seeks help in selecting the next superintendent. Any inventory of talents could well begin with a review of Mrs. McKenzie's many contributions, not the least of which is a notable improvement in students' performances.

Mrs. McKenzie's initiatives have included the establishment of important partnerships with business -- from small local firms to huge national corporations -- and her ability to recognize and reward teacher excellence. Clearly these and other accomplishments have earned her the respect of school board members -- which, in turn, has led to a genuinely constructive relationship between administrator and overseers. That is a critical commodity that should not be squandered by any shortsighted choice of a successor. If history is any indicator of success, the search could well begin closer to home and farther from those whose claims to be educators rest too much either on grand curriculum overhauls or on small-time policies ill-suited to the urban demands of this capital city.

It won't be easy. But thanks to the legacy of Floretta McKenzie, there is momentum, there is a sense of what can continue to happen -- and a new wave of young people better equipped to contribute to their community. It is no time to let up or let go.