Glossary

MTR. See military training route. National Transportation Safety Board (NTSB). A United States Government independent organization responsible for Multi-function display (MFD). Small screen (CRT or LCD) investigations of accidents involving aviation, highways, in an aircraft that can be used to display information to the waterways, pipelines, and railroads in the United States. pilot in numerous configurable ways. Often an MFD will be NTSB is charged by congress to investigate every civil used in concert with a primary flight display. aviation accident in the United States. MVA. See minimum vectoring altitude. NAVAID. Navigational aid. N NAV/COM. Navigation and communication radio. N . Rotational speed of the low pressure compressor in a 1 turbine engine. NDB. See nondirectional radio beacon. N . Rotational speed of the high pressure compressor in a 2 Negative static stability. The initial tendency of an aircraft turbine engine. to continue away from the original state of equilibrium after being disturbed. Nacelle. A streamlined enclosure on an aircraft in which an engine is mounted. On multiengine propeller-driven Neutral static stability. The initial tendency of an aircraft airplanes, the nacelle is normally mounted on the leading to remain in a new condition after its equilibrium has been edge of the wing. disturbed. NACG. See National Aeronautical Charting Group. NM. Nautical mile. NAS. See National Airspace System. NOAA. National Oceanic and Atmospheric Administration. National Airspace System (NAS). The common network of No-gyro approach. A radar approach that may be used in United States airspace—air navigation facilities, equipment case of a malfunctioning gyro-compass or directional gyro. and services, airports or landing areas; aeronautical charts, Instead of providing the pilot with headings to be flown, information and services; rules, regulations and procedures, the controller observes the radar track and issues control technical information; and manpower and material. instructions “turn right/left” or “stop turn,” as appropriate. National Aeronautical Charting Group (NACG). A Nondirectional radio beacon (NDB). A ground-based radio Federal agency operating under the FAA, responsible for transmitter that transmits radio energy in all directions. publishing charts such as the terminal procedures and en route charts. Nonprecision approach. A standard instrument approach procedure in which only horizontal guidance is provided. National Route Program (NRP). A set of rules and procedures designed to increase the flexibility of user flight No procedure turn (NoPT). Term used with the appropriate planning within published guidelines. course and altitude to denote that the procedure turn is not required. National Security Area (NSA). Areas consisting of airspace of defined vertical and lateral dimensions established at locations NoPT. See no procedure turn. where there is a requirement for increased security and safety of ground facilities. Pilots are requested to voluntarily avoid NOTAM. See Notice to Airmen. flying through the depicted NSA. When it is necessary to provide a greater level of security and safety, flight in NSAs Notice to Airmen (NOTAM). A notice filed with an aviation may be temporarily prohibited. Regulatory prohibitions are authority to alert aircraft pilots of any hazards en route or at disseminated via NOTAMs. a specific location. The authority in turn provides means of disseminating relevant NOTAMs to pilots. G-21