Aeronautical Terms beginning with N

National Airspace System (NAS)

Consists of a complex collection of facilities, systems, equipment, procedures, and airports operated by thousands of people to provide a safe and efficient flying environment.

Navigational Gap

A navigational course guidance gap, referred to as an MEA gap, describes a distance along an airway or route segment where a gap in navigational signal coverage exists. The navigational gap may not exceed a specific distance that varies directly with altitude.

Nondirectional Radio Beacon (NDB)

An L/MF or UHF radio beacon transmitting nondirectional signals whereby the pilot of an aircraft equipped with direction finding equipment can determine bearing to or from the radio beacon and home on or track to or from the station. When the radio beacon is installed in conjunction with the ILS marker, it is normally called a compass locator.