Today, exactly seven years after she was sworn in as a judge of the U.S. Court of Appeals here, Patricia McGown Wald becomes its chief judge and the first woman to serve a regular term as head of a federal appellate court.

Wald, 57, succeeds Spottswood W. Robinson III, the chief judge since May 1981, who is stepping down from that position because he has reached the post's mandatory retirement age of 70. Robinson will remain an active judge on the court.

Wald is one of 168 judges who sit on the nation's federal appeals courts. Eighteen of them are women.

She has reached the chief judge's post -- which is accorded based on seniority -- because of the extraordinary turnover on the court here. Robinson is the only active judge remaining of those sitting on the circuit when Wald was appointed.

The appeals court here often is considered the second most influential court in the nation because of the cases that come before it, since the government is a party in 98 percent of them. Wald said in a recent interview, "I'd rather be a judge on this circuit than any other circuit in the United States.

"I work hard, I enjoy what I'm doing and I try to come as close as I can to finding the right answer," Wald said. "But I have no delusions that I am always right."

A Connecticut native who studied law at Yale, Wald is considered bright, articulate, skilled at questioning attorneys on both sides of an issue and prolific in her opinion-writing.

Her professional experience before joining the court was primarily in the public sector, including stints as the litigation director of the Mental Health Law Project and as assistant attorney general for legislative affairs under former attorney general Griffin B. Bell.

Wald is well known for her liberal views; during confirmation hearings a fundamentalist minister called her "an instrument of the devil" because of her outspoken advocacy of legal rights of children. Many critics say she has mellowed during her years on the bench.

"I believe I had learned from the judging experience . . . and I hope I have grown with the job," Wald said.

But others believe she is too "result-oriented," that she first decides how she wants a case to come out and then searches for a legal basis for that conclusion.

Wald disagrees. "There are many cases I've decided that I'd like for the outcome to have been different," she said. "There is a lot of discretion in judging . . . relying on the knowledge and experience of different judges.

"A judge couldn't be entirely result-oriented," she said, noting that "if you are too far out, the entire court will en banc you or the Supreme Court will reverse you."

Wald began her legal career at Arnold and Porter but took off more than a decade to raise a family. All five children are now away from home, and two are lawyers. Her husband, also a lawyer, is in private practice here.

Wald said she is acutely aware of her place in history as the first woman to be an appellate chief judge for a regular term, and the growing presence of women in the legal profession. "When I first came on the bench there were some women presenting oral arguments, but they were mostly for the government. Now there are a lot more, and women are also representing more private clients," she said.

While women now constitute about half of the nation's law school students, there is still a wide disparity between the number in entry-level positions and the number who become law firm partners.

Female judges are still a "small fraternity," said Wald. When Jimmy Carter became president in 1977, there was only one female appellate judge -- Shirley Hufstedler of the 9th Circuit, who later resigned to become secretary of education.

Of the 18 sitting woman appellate judges, 12 were appointed by Carter; Reagan has named six.

No woman sat on the appeals court until 1934, when President Franklin D. Roosevelt appointed Florence Allen to the 6th Judicial Circuit. She served on the court until 1959 and was the circuit's chief judge for about five months until February 1959. But Allen's tenure as chief judge was mostly honorary.

Wald is expected to serve a full seven-year term in the job, which gives her overall responsibility for the operation of the court. She describes it as "seeing that judges use their judge time most effectively."

She said she believes that efficient operation of the court is essential in the current atmosphere of change. There is one opening on the court, to which Reagan is expected to name Assistant Attorney General Douglas Ginsburg, and another is expected because of the nomination of Antonin Scalia to the Supreme Court.

And when the court convenes its 1986-87 session in September, it will have a conservative majority for the first time in decades.

Wald said she was pleased that unlike some circuits, the chief judge here does not choose jurists for the three-judge panels that normally hear cases. "I wouldn't want to set the panels," she said. Judges for the panels here are selected by the court clerk and circuit counsel, based on seniority.

With Robinson's help, Wald has spent several months preparing for her new post, focusing on ways to trim the court's burgeoning backlog of cases, estimated to number about 2,000.

Her first major project will be to implement a new, streamlined case management schedule, which goes into effect next week. Wald said she hopes the plan, the result of a long study by Judges Harry T. Edwards, Laurence Silberman and James T. Buckley, will trim the amount of paperwork in most cases and encourage attorneys to settle more cases out of court.