(AP) — A small eastern Wisconsin airport gets the designation of "world's busiest" once a year during a yearly plane convention.

That makes for a lot of coordination and communication among the pilots and air traffic controllers during the weeklong Experimental Aircraft Association's AirVenture at Wittman Regional Airport in Oshkosh.

Air Traffic Manager Chuck Howard says there are sometimes as many planes coming and going in a day as Chicago's O'Hare International Airport but in half the time.

Howard described the tower as "controlled chaos" with 17,000 takeoffs and landings before and during the event being handled by the most experienced controllers. There are also people coordinating near the runways and at two remote locations.

According to the Federal Aviation Administration, the busiest airport switches between O'Hare and Hartsfield-Jackson Atlanta International Airport.