Every year since 1953, the Experimental Aircraft Association  holds its Fly-In Convention in Wisconsin. Now known as EAA AirVenture Oshkosh, the event is America's largest annual gathering of aviation enthusiasts. Between 300,000 and 500,000 visitors are expected to attend the airshow this year, and EAA estimates 10,000 to 15,000 aircraft will be at the event. This will make the control tower at the host airport, Wittman Regional Airport, the busiest in the world during the gathering. The show began Monday, July 29, and will close at the end of this week on August 4.