Localizer Performance with Vertical Guidance (LPV). Provides lateral containment areas comparable to an ILS localizer and decision heights between those of LNAV/ VNAV approaches and Category I ILS approaches. Approach procedure minimums that use WAAS to provide Localizer Performance with Vertical guidance (LPV). WAAS avionics equipment is required to fly to LPV minimums, which are published as DA (decision altitude). 

Long range navigation (LORAN). LOng RAnge Navigation ground‑based electronic navigation system using hyperbolic lines of position determined by measuring the difference in the time of reception of synchronized pulse signals from fixed transmitters. LORAN‑C and eLORAN operate in the 100–110 kHz frequency band. Enhanced LORAN (eLORAN) is planned to operate using more stable timing signals and stations from other chains for greater accuracy than the current LORAN‑C system. 

LPV.  See localizer performance with vertical guidance. 

LORAN-C.  See long range navigation. 

Magnetic flux valve.  A type of magnetometer using coils of wire as the transmitting portion of a synchronous repeating system, conventionally used to stabilize and correct a slaved gyroscopic heading (azimuth) indicator by sensing changes in the earth’s magnetic field. 

Magnetometer.  The device that measures the strength of the earth’s magnetic field to determine aircraft heading, and similar to the flux valve in function. 

MFD.  See multi‑function display. 

Mode awareness.  The pilot’s ability to monitor how system settings are configured throughout the flight. 

Moving map. A graphical depiction of aircraft position, route programmed into the FMS/RNAV, surrounding geographical features, and any other information about the immediate flight environment such as traffic and weather that may be available from other avionics systems. 

Multi-function display (MFD).  A cockpit display capable of presenting information received from a variety of advanced avionics systems. 

Navigation database.  The information stored in the FMS/ RNAV; contains most of the time‑sensitive navigational information found on en route and procedural charts. 

Navigation function. An autopilot function that allows you to track the route programmed in the FMS/RNAV or navigation receiver, such as a VOR radial. 

Next Generation Radar System. A network of radar stations operated by the National Weather Service used to detect precipitation and wind. These data are used to prepare weather radar products that can be supplied to the cockpit via a broadcast weather service. 

NEXRAD. See Next Generation Radar System. 

Nonsequencing mode.  The FMS/RNAV navigation mode that does not automatically sequence between waypoints in the programmed route. The nonsequencing mode maintains the current active waypoint indefinitely, and allows the pilot to specify desired track to or from that waypoint. 

No-further-input prediction. A technique to help pilots maintain awareness of how advanced avionics systems are configured, and of the likely future behavior of the aircraft. No‑further‑input predictions are made by considering what the aircraft will do if the pilot makes no further entries or commands. 

Nuisance alert. A term used to describe a “false alarm” provided by an avionics system designed to detect surrounding hazards such as proximate traffic and terrain. 

OBS mode.  The name for the nonsequencing mode on some FMS/RNAV units. See nonsequencing mode. 

Onboard lightning detection systems.  An onboard weather detection system that senses electrical discharges that suggest the presence of thunderstorm cells. 

Onboard weather radar.  An onboard system capable of detecting significant masses of precipitation. The primary use of weather radar is to aid the pilot in avoiding thunderstorms and their associated hazards. 

Page.  Any one of a collection of information displays that can appear on the FMS/RNAV unit. Every page has a title and presents information related to a particular navigation topic (e.g., airport elevation, runways, communication frequencies). Pages are usually in divisions called “chapters,” which group pages of similar information by topic (e.g., airports, approaches, VORs). 

PFD.  See primary flight display. 

