Drago Jovanovich

Dragoljub Kosta Jovanovich (January 24, 1916 – November 12, 1983), also known under his pen name D. K. or "Gish" Jovanovich, was a Serbian-American helicopter designer, inventor, and pioneer in autogyro technology. Born in the Kingdom of Yugoslavia, he subsequently moved to the United States, living first in Philadelphia and later in southern California. Provided by Wikipedia