During EAA AirVenture Oshkosh, two additional temporary runways are in operation to accommodate the high volume of traffic of numerous aircraft sizes and types: a portion of Taxiway A to the east of runway 18/36 becomes Runway 18L/36R (Runway 18/36 is re-designated 18R/36L and shortened to 6,700 feet) and a small grass runway (1,200 x 100 feet (366 x 30 m)) on the southern end of the airport is used to host ultralight aircraft. Runways 5/23 and 13/31 are closed during AirVenture.