Retired Rear Adm. Robert G. (Bob) Armstrong, 76, a Navy aviator whose last assignment was chief of staff of U.S. Naval Forces in Europe, died Nov. 24 at the Rockville Nursing Home, where he has been a resident for about a year and a half. He had arteriosclerosis.

After retiring from military service in 1956 while on duty in Heidelberg, Germany, Adm. Armstrong returned here and served for 10 years as an executive of the Aircraft Owners and Pilots Association. He moved to Sarasota, Fla., in 1966 and returned to Bethesda seven years later.

He was born in Wakefield, Neb. He graduated from the U.S. Naval Academy at Annapolis in 1926 and trained as an aviator at Pensacola, Fla.

In the early part of World War II, Adm. Armstrong was bombing squadron commander on the carrier Yorktown and was aboard when it was sunk during the Battle of Midway in 1942. Later he led a bombing squadron over New Guinea in an attack against the enemy and received the Navy Cross. He also held the Legion of Merit. In the latter part of the war, he was commanding officer of an aircraft tender repair ship in the Pacific.

Adm. Armstrong was a member of the Bethesda-Chevy Chase Rotary Club.

He is survived by his wife, Mildred S., of Bethesda; two daughters, Roberta A. Hobbs of Bethesda, and Wanda Heller of Sarasota; a brother, Dr. Willard P. Armstrong, and a sister, Josephine Anthoney, both of St. Louis, and five grandchildren.