The U.S. National Airspace System (NAS) is
|“||the common network of U.S. airspace; air navigation facilities, equipment, and services; airports or landing areas; aeronautical charts, information and services; rules, regulations, and procedures; technical information; and manpower and material.||”|
"Our National Airspace System (NAS) has evolved to include a wide variety of fixed wing and rotary aircraft of various sizes, weights, and speeds, operating across the country from populated complex metropolitan areas to remote airfields supporting small communities. They operate in a range of airspace, from low-altitude to the stratosphere. Some are dependent on thermals and wind, such as gliders and balloons, and others fly faster than the speed of sound, such as supersonic planes and spacecraft. As aircraft technology expands, so do the challenges associated with maintaining a safe and integrated NAS. And, with the recent advent of and growing interest in remotely piloted aircraft — commonly known as Unmanned Aircraft Systems (UAS) — addressing these challenges in a complex, multi-layered system has never been more critical. UAS are to be integrated in an already shaped and automated NAS and Air Traffic Control (ATC) environment that was originally developed for manned aircraft."