The Division of Aeronautics works with local airport agencies to maintain and upgrade the state's airport system. The division is responsible for developing aviation safety programs, aerospace education programs, providing emergency medical transportation and administrative assistance to the Civil Air Patrol. They oversee more than 20,000 registered pilots and more than 10,000 registered airplanes. The division can be contacted at Capital Airport, Springfield, Illinois 62707, (217) 785-8515. Illinois' airport system is the second largest in the nation and includes 138 airports, 280 heliports and nine balloon ports. Among the airports for general public service is O'Hare International in Chicago--the world's busiest airport which serves more than 60 million passengers annually. Currently, IDOT is undertaking a major planning effort for a new south suburban airport to meet the growing airline traffic needs in northeastern Illinois