Aviation business leaders say a dearth of plane parking spaces in the state`s airports is a problem. The Little Rock Municipal Airport Commission has heard there is a shortage of genaral aviation hangar space at National Airport, Adams Field. Little Rock Business Aviation Association member Walter Smiley said central Arkansas is out of general aviation hangars. The association said it has been warning airport officials for the last two years that National needs a better general aviation plan. Another association member, Bob East, said that if a corporation wanted to house its jets in Little Rock, it wouldn`t be able to. Hangars are essential because the Arkansas summer heat and sun can damage the avionics.