PHAK Glossary: N

Rotational speed of the low pressure compressor in a turbine engine.

Rotational speed of the high pressure compressor in a turbine engine.

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.

See National Aeronautical Charting Group.

See National Airspace System.

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.

A Federal agency operating under the FAA, responsible for publishing charts such as the terminal procedures and en route charts.

A set of rules and procedures designed to increase the flexibility of user flight planning within published guidelines.

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.

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.

Navigational aid.

Navigation and communication radio.

See nondirectional radio beacon.

The initial tendency of an aircraft to continue away from the original state of equilibrium after being disturbed.

The initial tendency of an aircraft to remain in a new condition after its equilibrium has been disturbed.

Nautical mile.

National Oceanic and Atmospheric Administration.

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.

A ground-based radio transmitter that transmits radio energy in all directions.

A standard instrument approach procedure in which only horizontal guidance is provided.

Term used with the appropriate course and altitude to denote that the procedure turn is not required.

See no procedure turn.

See Notice to Airmen.

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.

See National Route Program.

See National Security Area.

See National Transportation Safety Board.

National Weather Service.