Ognjeslav Kostovic (1851- 1916)
Ognjeslav Kostović Stepanović was a Serbian inventor. He was born in Wiesburg, Austria to a Serbian noble family residing in Pesta, Hungary, but spent most of his life in Saint Petersburg, Russia. He was In 1879 he demonstrated his flying models of a helicopter, aircraft and ornithopter, while in 1881 approached the building of an aircraft. In the catalog of aeronautical exhibition 1911 and in the article of G.V. Piotrovski it is said, that Kostović actually constructed a flight vehicle. The same was also said in A. Ewald's report in the Russian technical society on 12 March 1883.