After tests in the wind tunnel at Warsaw and acceptance by the Yugoslavian Air Force, the project was designated Zmaj R-1.
Djordje Ducić and a few young engineers who worked on the design completed the prototype before the beginning of a large aerospace workers strike in April 1940, with final assembly at the military part of the airport in Zemun.
The aircraft was rebuilt so that testing could be resumed at the end of March 1941, but in early April the bombing of Zemun airport damaged the prototype Zmaj R-1 again.
The reconnaissance variant carried cameras, extra fuel tanks and three crew members in lieu of guns and bombs.
Due to the cessation of flight testing the plans for the Yugoslav Royal Air Force reconnaissance and bomber units to be solely equipped with the Zmaj R-1 came to naught.