 It included a large hangar which was designed by Serbian scientist Milutin Milanković, who until then has been abroad engaged in the development of similar projects, and developed the world's first formula for determining the reinforcement of concrete beams.The airport was built on a meadow called Dojno Polje between Bežanijska Kosa and left bank of the Sava River, about two kilometers from Zemun.Airport had four grass runways.