The Metropolitan Airports Commission, also known as MAC, was founded in 1943. It operates one of the largest aviation systems in the United States. The commission operates several divisions, such as finance and administrative services, planning and environment, operations, human resources, legal affairs, labor relations and business development. It has a purchasing department that oversees purchasing, renting, leasing, selling and disposal of materials, equipment and supplies. The department also offers construction, repair and maintenance services for personal properties. The Metropolitan Airports Commission s risk and insurance department offers risk identification, evaluation and measurement and claims administration services. The commission additionally maintains a data resources department.