Aeronautical Terms beginning with N
NAS
National Airspace System
National Airspace System
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. Included are system components shared jointly with the military.
National Beacon Code Allocation Plan Airspace
Airspace over United States territory located within the North American continent between Canada and Mexico, including adjacent territorial waters outward to about boundaries of oceanic control areas (CTA)/Flight Information Regions (FIR).
National Flight Data Center
A facility in Washington D.C., established by FAA to operate a central aeronautical information service for the collection, validation, and dissemination of aeronautical data in support of the activities of government, industry, and the aviation community. The information is published in the National Flight Data Digest.
National Flight Data Digest
A daily (except weekends and Federal holidays) publication of flight information appropriate to aeronautical charts, aeronautical publications, Notices to Airmen, or other media serving the purpose of providing operational flight data essential to safe and efficient aircraft operations.
National Search And Rescue Plan
An interagency agreement which provides for the effective utilization of all available facilities in all types of search and rescue missions.
NAVAID
Navigational Aid
Navaid Classes
VOR, VORTAC, and TACAN aids are classed according to their operational use. The three classes of NAVAIDs are: a. T-Terminal. b. L-Low altitude. c. H-High altitude. Note: The normal service range for T, L, and H class aids is found in the AIM. Certain operational requirements make it necessary to use some of these aids at greater service ranges than specified. Extended range is made possible through flight inspection determinations. Some aids also have lesser service range due to location, terrain, frequency protection, etc. Restrictions to service range are listed in Airport/Facility Directory.
Navigable Airspace
Airspace at and above the minimum flight altitudes prescribed in the CFRs including airspace needed for safe takeoff and landing.
Navigation Reference System (NRS)
The NRS is a system of waypoints developed for use within the United States for flight planning and navigation without reference to ground based navigational aids. The NRS waypoints are located in a grid pattern along defined latitude and longitude lines. The initial use of the NRS will be in the high altitude environment in conjunction with the High Altitude Redesign initiative. The NRS waypoints are intended for use by aircraft capable of point-to-point navigation.
Navigation Specification [ICAO]
A set of aircraft and flight crew requirements needed to support performance-based navigation operations within a defined airspace. There are two kinds of navigation specifications: RNP and RNAV. Note: The Performance-based Navigation Manual (Doc 9613), Volume II contains detailed guidance on navigation specifications.
Navigational Aid
Any visual or electronic device airborne or on the surface which provides point-to-point guidance information or position data to aircraft in flight.
NBCAP AIRSPACE
National Beacon Code Allocation Plan Airspace
NDB
Nondirectional Beacon
Negative
“No,” or “permission not granted,” or “that is not correct.”
Negative Contact
Used by pilots to inform ATC that: a. Previously issued traffic is not in sight. It may be followed by the pilot’s request for the controller to provide assistance in avoiding the traffic. b. They were unable to contact ATC on a particular frequency.
NFDC
National Flight Data Center
NFDD
National Flight Data Digest
Night
The time between the end of evening civil twilight and the beginning of morning civil twilight, as published in the American Air Almanac, converted to local time.
Night [ICAO]
The hours between the end of evening civil twilight and the beginning of morning civil twilight or such other period between sunset and sunrise as may be specified by the appropriate authority. Note: Civil twilight ends in the evening when the center of the sun’s disk is 6 degrees below the horizon and begins in the morning when the center of the sun’s disk is 6 degrees below the horizon.
No Gyro Approach
A radar approach/vector provided in case of a malfunctioning gyro-compass or directional gyro. Instead of providing the pilot with headings to be flown, the controller observes the radar track and issues control instructions “turn right/left” or “stop turn” as appropriate.
No Gyro Vector
No Gyro Approach. A radar approach/vector provided in case of a malfunctioning gyro-compass or directional gyro. Instead of providing the pilot with headings to be flown, the controller observes the radar track and issues control instructions “turn right/left” or “stop turn” as appropriate.
No Transgression Zone (NTZ)
The NTZ is a 2,000 foot wide zone, located equidistant between parallel runway final approach courses in which flight is not allowed.
Non-Restrictive Routing (NRR)
Portions of a proposed route of flight where a user can flight plan the most advantageous flight path with no requirement to make reference to ground-based NAVAIDs.
Nonapproach Control Tower
Authorizes aircraft to land or takeoff at the airport controlled by the tower or to transit the Class D airspace. The primary function of a nonapproach control tower is the sequencing of aircraft in the traffic pattern and on the landing area. Nonapproach control towers also separate aircraft operating under instrument flight rules clearances from approach controls and centers. They provide ground control services to aircraft, vehicles, personnel, and equipment on the airport movement area.
Noncommon Route/Portion
That segment of a North American Route between the inland navigation facility and a designated North American terminal.
Noncomposite Separation
Separation in accordance with minima other than the composite separation minimum specified for the area concerned.
Nondirectional Beacon
An L/MF or UHF radio beacon transmitting nondirectional signals whereby the pilot of an aircraft equipped with direction finding equipment can determine his/her 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 Instrument Landing System marker, it is normally called a Compass Locator.
Nonmovement Areas
Taxiways and apron (ramp) areas not under the control of air traffic.
Nonprecision Approach
Nonprecision Approach Procedure.
Nonprecision Approach Procedure
A standard instrument approach procedure in which no electronic glideslope is provided; e.g., VOR, TACAN, NDB, LOC, ASR, LDA, or SDF approaches.
Nonprecision Approach Runway
An instrument runway served by visual aids and a nonvisual aid providing at least directional guidance adequate for a straight-in approach.
Nonradar
Precedes other terms and generally means without the use of radar, such as: Nonradar Approach, Nonradar Approach Control, Nonradar Arrival, Nonradar Route, and Nonradar Separation.
Nonradar Approach
Used to describe instrument approaches for which course guidance on final approach is not provided by ground-based precision or surveillance radar. Radar vectors to the final approach course may or may not be provided by ATC. Examples of nonradar approaches are VOR, NDB, TACAN, and ILS/MLS approaches.
Nonradar Approach Control
An ATC facility providing approach control service without the use of radar.
Nonradar Arrival
An aircraft arriving at an airport without radar service or at an airport served by a radar facility and radar contact has not been established or has been terminated due to a lack of radar service to the airport.
Nonradar Route
A flight path or route over which the pilot is performing his/her own navigation. The pilot may be receiving radar separation, radar monitoring, or other ATC services while on a nonradar route.
Nonradar Separation
The spacing of aircraft in accordance with established minima without the use of radar; e.g., vertical, lateral, or longitudinal separation.
Nonradar Separation [ICAO]
The separation used when aircraft position information is derived from sources other than radar.
NOPAC
North Pacific
NORDO
(No Radio) Aircraft That Cannot Or Do Not Communicate By Radio When Radio Communication Is Required Are Referred To As “Nordo.
Normal Operating Zone (NOZ)
The NOZ is the operating zone within which aircraft flight remains during normal independent simultaneous parallel ILS approaches.
North American Route
A numerically coded route preplanned over existing airway and route systems to and from specific coastal fixes serving the North Atlantic. North American Routes consist of the following: a. Common Route/Portion. That segment of a North American Route between the inland navigation facility and the coastal fix. b. Noncommon Route/Portion. That segment of a North American Route between the inland navigation facility and a designated North American terminal. c. Inland Navigation Facility. A navigation aid on a North American Route at which the common route and/or the noncommon route begins or ends. d. Coastal Fix. A navigation aid or intersection where an aircraft transitions between the domestic route structure and the oceanic route structure.
North American Route Program (NRP)
The NRP is a set of rules and procedures which are designed to increase the flexibility of user flight planning within published guidelines.
North Mark
A beacon data block sent by the host computer to be displayed by the ARTS on a 360 degree bearing at a locally selected radar azimuth and distance. The North Mark is used to ensure correct range/azimuth orientation during periods of CENRAP.
North Pacific
An organized route system between the Alaskan west coast and Japan.
NOTAM
Notice To Airmen
NOTAM [ICAO]
A Notice Containing Information Concerning The Establishment, Condition Or Change In Any Aeronautical Facility, Service, Procedure Or Hazard, The Timely Knowledge Of Which Is Essential To Personnel Concerned With Flight Operations. A. I Distribution-Distribution By Means Of Telecommunication. B. II Distribution-Distribution By Means Other Than Telecommunications
NOTAM(D)
A NOTAM Given (In Addition To Local Dissemination) Distant Dissemination Beyond The Area Of Responsibility Of The Flight Service Station. These NOTAMs Will Be Stored And Available Until Canceled
Notice To Airmen
A notice containing information (not known sufficiently in advance to publicize by other means) concerning the establishment, condition, or change in any component (facility, service, or procedure of, or hazard in the National Airspace System) the timely knowledge of which is essential to personnel concerned with flight operations. There are two types: NOTAM(D) and FDC NOTAM.
Notices To Airmen Publication
A publication issued every 28 days, designed primarily for the pilot, which contains current NOTAM information considered essential to the safety of flight as well as supplemental data to other aeronautical publications. The contraction NTAP is used in NOTAM text.
NRR
Non-Restrictive Routing
NRS
Navigation Reference System
NTAP
Notices To Airmen Publication
Nuisance Alert
An alert in which one or more of the following is true: 1. The alert is generated by a known situation that is not considered an unsafe operation, such as LAHSO or other approved operations. 2. The alert is generated by inaccurate secondary radar data received by the Safety Logic System. 3. One or more of the aircraft involved in the alert is not intending to use a runway (for example, helicopter, pipeline patrol, non-Mode C overflight, etc.).
Numerous Targets Vicinity (Location)
A traffic advisory issued by ATC to advise pilots that targets on the radar scope are too numerous to issue individually.
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