PCG NAS -- NUMEROUS TARGETS VICINITY (LOCATION)
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).
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 FLIGHT INFORMATION REGION.)
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
(See NATIONAL FLIGHT DATA DIGEST.)
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
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- (See NATIONAL BEACON CODE ALLOCATION PLAN AIRSPACE.)
(See AIR NAVIGATION FACILITY.)
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
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"
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
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.
NONMOVEMENT AREAS- Taxiways and apron (ramp) areas not under the control
of air traffic.
(See AUTOMATIC DIRECTION FINDER.)
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.
NONRADAR SEPARATION [ICAO]- The separation used when aircraft position
information is derived from sources other than radar.
(See ICAO term NONRADAR SEPARATION.)
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
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
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
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
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
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.)