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 . own, 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.
Obstacle departure procedures (ODP). Obstacle clearance protection provided to aircraft in instrument meteorological conditions (IMC).
ODP. See obstacle departure procedures.
OM. Outer marker.
Omission error. The failure to anticipate significant instrument indications following attitude changes; for example, concentrating on pitch control while forgetting about heading or roll information, resulting in erratic control of heading and bank.