Niš Constantine the Great Airport (Serbian: Аеродром Константин Велики Ниш/Aerodrom Konstantin Veliki Niš) (IATA: INI, ICAO: LYNI), located 4 km (2.5 mi) northwest of downtown Niš, in the suburbs of Medoševac and Popovac. It is the second-largest and second-busiest airport in Serbia, after Belgrade Nikola Tesla Airport. Niš Military Air Base (Serbian Air Force and Air Defence), the Serbian-Russian Emergency Response Centre and Centre for Aerial Firefighting Duties are all located on the site of the airport.