Andrew M. Hood. 78, a retired chief judge of the D. C. Court of Appeals, died yesterday at Doctors Hospital in Washington. He had been hospitalized three weeks ago for treatment of pulmonary disorders.

Judge Hood began his career on the bench as one of the three original members of the old D. C. Municipal Court of Appeals when it was established in 1942. He was appointed by President Franklin D. Roosevelt and received subsequent appointments by Presidents Harry S. Truman, Dwight D. Eisenhower, John F. Kennedy, who named him chief judge in 1962, and by Lyndon B. Johnson.

He retired in 1972, but remained active on the court as a senior judge until about a month before his death. His last published opinion was handed down on May 2 and clarified a distinction between federal and D. C. Narcotics Laws.

In the 3m years in which Judge Hood sat as an active or senior judge, the court underwent profound changes. These paralleled the city's slow progress towards home rule. Judge Hood oversaw these changes on the court. His role as a judicial administrator was as pronounced as his role as an appellate judge.

When it was formed in 1942, the Municipal Court of Appeals reviewed decisions of the District's police, municipal and juvenile courts. Major legal questions at that time, including civil cases, felonies, and the probate of wills, were handled by the U.S. District Court. Appeals from the District Court went to the U.S. Courts of Appeals for the District of Columbia.

In 1968, Congress passed the first of two laws reorganizing the city's judicial system. The Municipal Court of Appeals had become the D. C. Court of Appeals. Its membership was expanded from three to six judges and later to nine judges. In 1970, Congress passed a second court reorganization act that provided for the gradual transfer to D. C. Superior Court, formerly the Municipal Court, of all major civil and criminal matters that previously had gone before the U.S. District Court.

Under the 1968 act, the D.C. Court of Appeals was given the power to review orders of the City Council and other city agencies. It was well on the way toward becoming the District's highest court of appeals when Judge Hood retired in 1972. Since then, the provisions of the 1970 act have been implemented fully. Decisions of the D.C. Court of Appeals are appealable only to the U.S. Supreme Court. Previously, they were reviewable by the U.S. Court of Appeals.

In an interview at the time of his retirement, Judge Hood said, "I consider my greatest contribution has been as a part of this court from the time it was established in 1942 as a very limited appeals court. Over that time, I've watched it grow to maturity."

As the city's chief judicial appellate body, the Court of Appeals also promulgated the D.C. Bar, also known as the Unified Bar, to which all attorneys who practice in the city must belong. The D.C. Bar, under the supervision of the court, sets the rules for the practice of law here and undertakes disciplinary functions which then are referred to the court for final action.

In short, in the years in which Judge Hood served on the bench, the District has acquired a court system that has the same powers as those exercised by any state court system. Previously, these powers were exercised here by the federal courts.

As for his work on the bench, Judge Hood said in 1972 that he thought his court "has been more of a traditionalist than an activist court." Partly because of the review function of the D.C. Court of Appeals, he said, "we were never free to indulge in activism, although I don't say that we wanted to."

Thus, under Judge Hood, the D.C. Court of Appeals broadened the rights of police to make searches and narrowed the rights of defendants in criminal cases. A continuing question before the court was whether to exclude evidence from criminal trials that was useful to the prosecution simply because it may have been illegally obtained.

In Judge Hood's view, changes involving the admissibility of evidence - and similer questions - should be made by legislative bodies and not by courts. Speaking of criminal cases, he said, "So many of them have been cases where the guilt of the man is not an issue. He had the gun, or the dope, or the stolen property in his pocket." He said he thought it would "bother any judge" to release an obviously guilty man on a technicality.

Andrew McCaughrin Hood was born in Anderson, S.C. He grew up there and graduated from Erskine College in 1921. He then moved to Washington to study law at Georgetown University, from which he earned his law degree in 1924. He was admitted to the bar in the same year and engaged in private practice until his first appointment to the bench in 1942. He was an adjunct professor at the Georgetown Law School from 1937 to 1962 and received the biennial medal from the school in 1957.

He had been a member of the Barristers since 1928. He was a member of the D.C. and American bar associations.

Survivors include his wife, Mildred, and a son, Peter A., both of the home in Washington, and a sister, Margaret Hood, and a brother, Kennedy Hood, both of Anderson, S.C. CAPTION: Picture, ANDREW M. HOOD