Opening day of AirVenture 2010 arrived yesterday, and this year's show has proved to be one of the most challenging in decades. With last week's torrential rains, EAA has struggled with pumping out and otherwise preparing a soggy Wittman Field in Oshkosh, bracing for the arrival of the usual complement of approximately 5,500 airplanes. As of yesterday morning's briefing, the field was open to "display" aircraft — including antiques, classics; warbirds and homebuilts as well as airshow performers' airplanes and display aircraft for manufacturers, vendors and others. Additional GA aircraft were allowed in if they had reserved parking on hard surfaces. Both FBOs on the field, Basler and Orion, have been scrambling to accommodate arrivals, shoehorning aircraft into every nook and cranny of their ramps. Many arriving aircraft diverted to satellite airports such as Appleton and Fond du Lac, as well as several smaller airports in the area where ramps were jammed with Oshkosh-bound aircraft from around the country. EAA was hoping to open more of the grass parking areas on Monday.