NAS -- NUMEROUS TARGETS VICINITY (LOCATION)
NAS- (See NATIONAL AIRSPACE SYSTEM.)
NAS STAGE A- The en route ATC system's radar, computers and computer
programs, controller plan view displays (PVD's/Radar Scopes), input/output
devices, and the related communications equipment which are integrated to form
the heart of the automated IFR air traffic control system. This equipment
performs Flight Data Processing (FDP) and Radar Data Processing (RDP). It
interfaces with automated terminal systems and is used in the control of en
route IFR aircraft.
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).
(See FLIGHT INFORMATION REGION.)
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.
(See 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 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.
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- (See NAVIGATIONAL AID.)
NAVAID CLASSES- VOR, VORTAC, and TACAN aids are classed according to their
operational use. The three classes of NAVAID's are:
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 FAR's including airspace needed for safe takeoff and landing.
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.
(See AIR NAVIGATION FACILITY.)
NBCAP AIRSPACE- (See NATIONAL BEACON
CODE ALLOCATION PLAN AIRSPACE.)
NDB- (See 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- (See NATIONAL FLIGHT DATA CENTER.)
NFDD- (See 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- (See NO GYRO
APPROACH.)
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.
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 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.
(See AUTOMATIC DIRECTION FINDER.)
NONMOVEMENT AREAS- Taxiways and
apron (ramp) areas not under the control of air traffic.
NONPRECISION APPROACH- (See 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.
NONRADAR- Precedes other terms and generally means without the use of radar,
such as:
a. 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.
(See FINAL APPROACH-IFR.)
(See FINAL APPROACH COURSE.)
(See INSTRUMENT APPROACH PROCEDURE.)
b. Nonradar Approach Control. An ATC facility providing approach
control service without the use of radar.
(See APPROACH CONTROL FACILITY.)
(See APPROACH CONTROL SERVICE.)
c. 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.
d. Nonradar Route. A flight path or route over which the pilot is
performing his own navigation. The pilot may be receiving radar separation,
radar monitoring, or other ATC services while on a nonradar route.
e. Nonradar Separation. The spacing of aircraft in accordance with
established minima without the use of radar; e.g., vertical, lateral, or
longitudinal separation.
(See ICAO term NONRADAR SEPARATION.)
NONRADAR SEPARATION [ICAO]-
The separation used when aircraft position information is derived from sources
other than radar.
NOPAC- (See NORTH PACIFIC.)
NORDO- (See LOST COMMUNICATIONS.)
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 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- (See NOTICE TO AIRMEN.)
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.
a. NOTAM(D)- A NOTAM given (in addition to local dissemination)
distant dissemination beyond the area of responsibility of the Flight Service
Station. These NOTAM's will be stored and available until canceled.
b. NOTAM(L)- A NOTAM given local dissemination by voice and other
means, such as telautograph and telephone, to satisfy local user
requirements.
c. FDC NOTAM- A NOTAM regulatory in nature, transmitted by USNOF
and given system wide dissemination.
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.
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.
NTAP- (See NOTICES TO AIRMEN PUBLICATION.)
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.
(See TRAFFIC ADVISORIES.)