Pilot/Controller Glossary

4/3/14

PCG N−1

N

NAS−

(See 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).

(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 aeronau-

tical data in support of the activities of government,

industry, and the aviation community. The informa-

tion 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 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 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.

(Refer to 14 CFR Part 91.)

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:

a.

RNP specification. A navigation specification

based on area navigation that includes the

requirement for performance monitoring and alert-

ing, designated by the prefix RNP; e.g., RNP 4, RNP

APCH.

b.

RNAV specification. A navigation specifica-

tion based on area navigation that does not include the

requirement for performance monitoring and alert-

ing, designated by the prefix RNAV; e.g., RNAV 5,

RNAV 1.

Note: The Performance

−

based Navigation Manual

(Doc 9613), Volume II contains detailed guidance
on navigation specifications.