Dr. Harold A. Haynes, 89, head of black public schools in the District of Columbia at the time the city's schools were desegregated, died July 31 at the Mar-Salle nursing home in Washington. He had suffered from arteriosclerosis.

He began his 39-year career in the D.C. public schools in 1919 as a teacher of applied electricity at Armstrong High School.He served as principal of Browne Junior High School in the 1930s and then Armstrong and Dunbar High schools during the 1940s.

Dr. Haynes was named associate superintendent of schools in 1948 and became the first assistant superintendent of schools - head of black public schools - in 1951.

After desegregation in 1954 he was named deputy superintendent of schools for coordinated services. In this position he helped supervise curriculum revision, reading clinics and schooling for the handicapped.

Dr. Haynes was related to educators by birth and marriage. A grandfather, Henry Johnson, had been a school board member during the 1800s when Washington had both black and white boards. Dr. Haynes's wife, Dr. Euphemia L. Haynes, was president of the D.C. Board of Education for a time during the 1960s.

He was a native of Washington and graduated from the old M Street High School. He earned a bachelor's degree in electrical engineering at the University of Pittsburgh, master's degree in education at the University of Chicago, and a doctorate in education at New York University.

Dr. Haynes began his taching career at Howard University in 1912, where he taught electrical engineering for six years before joining the D.C. schools.

As a teacher he believed that students should be exposed to practice as well as theory. During his years at Armstrong he frequently had his students working on wiring for commercial builders and in school buildings.

Speaking before a group of elementary school principals in 1954, he cited "too rapid and unbalanced" maturity in school children as a growing problem for educators. He said he believed children were changing "because of their experiences with radio, television, movies and modern comic books." He said juvenile delinquency could be attributed to this "too rapid , unbalanced maturity."

But at the time of his retirement in 1958. Dr. Haynes said that he had come to the conclusion that there were no really new problems in education. He said that there is only the always new and challenging "classroom situation - just the teacher and the student."

Dr. Haynes' professional memberships included the National Association of Secondary School Principals, the Columbian Educational Association, the American Association of School Administrators and the American Society for Engineering Education.

He was a member of the Pigskin Club and the East Central Civic Association.

He is survived by his wife, of the home in Washington.