Chapter 8 The National  Airspace System Introduction The National Airspace System (NAS) is the network of  all components regarding airspace in the United States.  This comprehensive label includes air navigation facilities,  equipment, services, airports or landing areas, sectional charts,  information/services, rules, regulations, procedures, technical  information, manpower, and material. Many of these system  components are shared jointly with the military. To conform  to international aviation standards, the United States adopted  the primary elements of the classification system developed  by the International Civil Aviation Organization (ICAO).  This chapter provides a general discussion of airspace  classification. Detailed information on the classifi cation of  airspace, operating procedures, and restrictions is found in  the Aeronautical Information Manual (AIM). 