Dr. A. S. Robotnikoff, 76, former chairman of the Slavic division of the Defense Language Institute, East Coast, in Washington, died Wednesday at his home in Arlington.

He came here in 1947 to teach Russian at the Naval Intelligence Language School, which subsequently became the Defense Language Institute, East Coast. He retired in 1972.

Dr. Rabotnikoff trained students, primarily military, to prepare for attache and other military posts requiring the Russian language.He helped train the military interpreters manning the Moscow-Washington Hotline and the U.S. astronauts involved in the space linkup with the Soviet cosmonauts.

Born in the Crimea, Dr. Rabotnikoff served in the White Army and left Russia for Turkey with the White Army when it was evacuted in 1920. He went on to Argentina and came to this country in 1924.

He spoke no English at the time, and worked as a manual laborer in New York. A year later, Cornell University agreed to admit him on condition he learn English.

Dr. Rabotnikoff mastered enough of the language in six months to undertake studies at Cornell and went on to receive a bachelor's degree in 1929. He remained at the university, earning a master's degree and then a doctoral degree in engineering and education.

After teaching science at Boynton Junior High School in Ithaca, he returned to Cornell, where he taught Russian during World War II.

He is survived by his wife, Maria, of the home; a daughter, Mrs. A. R. Burris, of Evanston, III., and a grandchild.

It is suggested that expressions of sympathy may be in the form of contributions to a scholarship in his name in the Russian department of Cornell University.