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 homeon 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.
Non-RNAV DP
A DP whose ground track is based on ground-based NAVAIDS and/or dead reckoning navigation.
N1,N2,N3
Spool speed expressed in percent rpm. N1 on a turboprop is the gas producer speed. N1 on a turbofan or turbojet engine is the fan speed or low pressure spool speed. N2 is the high pressure spool speed on engine with 2 spools and medium pressure spool on engines with 3 spools with N3 being the high pressure spool.
Nacelle
A streamlined enclosure on an aircraft in which an engine is mounted. On multiengine propeller-driven airplanes, the nacelle is normally mounted on the leading edge of the wing.
Negative Static Stability
The initial tendency of an aircraft to continue away from the original state of equilibrium after being disturbed.
Negative Torque Sensing (NTS)
A system in a turboprop engine that prevents the engine from being driven by the propeller. The NTS increases the blade angle when the propellers try to drive the engine.
Neutral Static Stability
The initial tendency of an aircraft to remain in a new condition after its equilibrium has been disturbed.
Nickel-Cadmium Battery (NiCad)
A battery made up of alkaline secondary cells. The positive plates are nickel hydroxide, the negative plates are cadmium hydroxide, and potassium hydroxide is used as the electrolyte.
Normal Category
An airplane that has a seating configuration, excluding pilot seats, of nine or less, a maximum certificated takeoff weight of 12,500 pounds or less, and intended for non-acrobatic operation.
Normalizing (Turbonormalizing)
A turbocharger that maintains sea level pressure in the induction manifold at altitude.
NACG
See National Aeronautical Charting Group.
NAS
See National Airspace System.
National Airspace System (NAS)
The common network of United States 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.
National Aeronautical Charting Group (NACG)
A Federal agency operating under the FAA, responsible for publishing charts such as the terminal procedures and en route charts.
National Route Program (NRP)
A set of rules and procedures designed to increase the flexibility of user flight planning within published guidelines.
National Security Area (NSA)
Areas consisting of airspace of defined vertical and lateral dimensions established at locations where there is a requirement for increased security and safety of ground facilities. Pilots are requested to voluntarily avoid flying through the depicted NSA. When it is necessary to provide a greater level of security and safety, flight in NSAs may be temporarily prohibited. Regulatory prohibitions are disseminated via NOTAMs.
National Transportation Safety Board (NTSB)
A United States Government independent organization responsible for investigations of accidents involving aviation, highways, waterways, pipelines, and railroads in the United States. NTSB is charged by congress to investigate every civil aviation accident in the United States.
NAVAID
Navigational aid.
NAV/COM
Navigation and communication radio.
NDB
See nondirectional radio beacon.
NM
Nautical mile.
NOAA
National Oceanic and Atmospheric Administration.
No-gyro approach
A radar approach that may be used 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.
Nondirectional radio beacon (NDB)
A ground-based radio transmitter that transmits radio energy in all directions.
Nonprecision approach
A standard instrument approach procedure in which only horizontal guidance is provided.
No procedure turn (NoPT)
Term used with the appropriate course and altitude to denote that the procedure turn is not required.
NoPT
See no procedure turn.
Notice to Airmen (NOTAM)
A notice filed with an aviation authority to alert aircraft pilots of any hazards en route or at a specific location. The authority in turn provides means of disseminating relevant NOTAMs to pilots.
NRP
See National Route Program.
NSA
See National Security Area.
NTSB
See National Transportation Safety Board.
NWS
National Weather Service.
Navigate
To move between websites on the internet. Navigation is often accomplished by means of links or connections between sites.
Norm-referenced testing
System of testing in which students are ranked against the performance of other students.
N1
Rotational speed of the low pressure compressor in a turbine engine.
N2
Rotational speed of the high pressure compressor in a turbine engine.
Nacelle
A streamlined enclosure on an aircraft in which an engine is mounted. On multiengine propeller-driven airplanes, the nacelle is normally mounted on the leading edge of the wing.
National Security Areas
Airspace that consists of defined vertical and lateral dimensions established at locations where there is a requirement for increased security and safety of ground facilities.
Ndb
See Nnon-Directional Radio Beacon.
Negative Static Stability
The initial tendency of an aircraft to continue away from the original state of equilibrium after being disturbed.
Neutral Static Stability
The initial tendency of an aircraft to remain in a new condition after its equilibrium has been disturbed.
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 the 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.
Notices To Airmen (NOTAM)
A notice containing time-critical information that is either of a temporary nature or is not known far enough in advance to permit publication on aeronautical charts or other operation publications. This can include the establishment, condition, or change in any facility, service, procedure, or hazard in the National Airspace System.
N90
New York TRACON
NAS
National Airspace System. The common network of U.S. airspace; air navigation facilities, equipment and services, airports or landing areas.
NAVAID
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.
NM
Nautical Mile. International unit equal to 6076.115 feet (1852 meters).
NOTAM
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.
NRP
North American Route Program. The NRP is a set of rules and procedures which are designed to increase the flexibility of user flight planning within published guidelines.