As the aviation authority for the nation's second largest city, and hub of one of the world's most populous metropolitan areas, Los Angeles World Airports (LAWA) is faced with the challenges of providing an airport system to serve a major portion of the Southern California market. LAWA has met this challenge, and at no cost to the taxpayer. Los Angeles World Airports is a self-supporting branch of the City of Los Angeles, governed by a seven-member Board of Airport Commissioners. The Board is composed of public-spirited business and civic leaders who are appointed by the mayor and approved by the City Council. Policies of the commission are carried out by a professional administrative staff and nearly 2,500 employees who operate and maintain four airports in the system: Los Angeles International Airport Ontario International Airport Van Nuys Airport Palmdale Regional Airport Airport revenues are derived from: Aircraft landing fees Leases and concession fees from more than 350 tenants Airport expenditures include: Bond redemption and interest Maintenance of buildings and airfields Operating and administrative expenses, equipment and roads