Definitions Acronyms

A/C

Air Craft, or simply airplane

A/P

Autopilot

A/T

Autothrottle, A/P Subsystem that controls the throttle

ADF

Automatic Direction Finder, tuned to NDB

AGL

Above Ground Level, height above the Ground over which you are currently flying

Apt Elev

Airport Elevation, the MSL of a central point of an airport

ASOS

Automated Surface Observation System, measures and broadcasts surface wheather info automatically

ATIS

Automatic Terminal Information Service

BC

Back Course, part of ILS, beacon that provides range information, like OM/MM/IM, specifies FAF for back course, a back course is non-precison since no ; G/S associated

CDI

Course Deviation Indicator, part of a VOR gauge, a needle showing whether you are on course (centered) or not (left or right)

CTAF

Common Traffic Advisory Frequency. Available at airfields with no operational control tower.

DG

Directional Gyro

DH

Decision Height, point on G/S where to decide to continue landing or missed approach, similar to MDA, for precision approaches, determined by altimeter, lowest height where an approach can be flown by instrument alone

DME

Distance Measuring Equipment, measures the distance(slant, not on-ground distance) to the tuned in VOR,

EFATO

Engine Failure after take-off - usually resulting in a force-landing.

EICAS

Engine Indication and Crew Alerting System

FAF

Final Approach Fix

FD

Flight Director, horizontal and vertical bars on your PD

G/S

Glideslope, provides vertical guidance during ILS, UHF, always goes together with LOC, usually 3deg, usable 10NM from field

GPS

Global Positioning System, allows a very exact measuring of location all over the world, based on satellites

HUD

Head Up Display

IAF

Initial Approach Fix

IAP

Intstrument Approach Plate, see Approach Plate, aka. Terminal Procedures

IATA

an Airport Designator, used on Flight Tickets, Baggage,...

ICAO

an Airport Designator, used for Navigation

IFR

Instrument Flight Rules, 0-179: odd thousands, 180-359: even thousands

ILS

Instrument Landing System

IM

Inner Marker, part of ILS, beacon that provides range information, only for Cat II where it is the DH point, 100ft from runway threshold

LDA

Localizer-type Directional Aid, similar to LOC, but offset from runway heading, the approach path is not lined up with runway

LNAV

Lateral Navigation,

LOC

Localizer, provides lateral guidance during ILS, VHF, always goes together with G/S, usable 18NM from field

LOC-A

an approach plate that ends with a letter indicates that a circling approach is required

MALSR

Medium intensity Approach Lighting System with Runway alignment indicator lights, a type of Runway Approach lighting

MAP

Missed Approach Point, touch down zone of runway

MDA

Minimum Descend Altitude, during an approach, this specifies the minimum Altitude (MSL) before the runway is in sight and a safe landing can be made

MEA

Mean Enroute Altitude

METAR

Meteorological Aerodrome Report

MIRL

Medium Intensity Runway Lights

MLS

Microwave Landing System

MM

Middle Marker, part of ILS, beacon that provides range information, 3500ft from runway threshold

MOCA

Minimum Obstruction Clearance Altitude

MSA

Minimum Safe Altitude, provides minimum of 1000ft clearance from obstructions and terrain

MSL

Mean Sea Level, Standardized height figure, Altimeters show the current A/C height over MSL

Navaid

Helper for navigation, eg: NDB, Fixes, VOR, GPS

ND

Navigation Display

NDB

Non Directional Beacon, LW, sends out Morse code of its ID, reception only reliable > 1000ft AGL

OAT

Outside Air Temperature, the temperature of undisturbed air, derived by correcting TAT for compressibility errors

OBS

Omni Bearing Selector, part of a VOR gauge, used to rotate the course card

OM

Outer Marker, part of ILS, beacon that provides range information, 4-7NM from runway threshold

PAPI

Precision Approach Path Indicator, similar to VASI, but more precise, uses four lights

PD

Primary Display

PF

Pilot Flying, the person that currently controls the airplane, can be either Captain or F/O

PFL

Practice Forced Landing. Practise approach carried out to a suitable field. No landing is made.

PIREP

Pilot Report (abbreviated UA in the briefing teletype, UUA is urgent PIREP)

PNF

Pilot Non-Flying, the person who's not the PF

RAT

Ram Air Temperature, the raw, non-corrected temp. as measured by the temperature probe. Errors due to the Ram effect (air compressed in the probe) and the position (air may be disturbed by parts of the airplane, and also due to the effect of the air compression in front of the plane) RAT may also describe a Ram Air Turbine; a device deployed into the airstream on large aircraft to provided minimum electrical power in the event of generator-failure.

RMI

Radio Magnetic Indicator

RNAV

Area Navigation, flying by longitude/latitude points that are not radio navigation aids, GPS or IRS is usually used.

RTO

Rejected Takeoff

RVR

Runway Visibility Range,

SAT

Static Air Temperature, same as OAT

SDF

Simple Directional Facility,

SID

Standard Instrument Departure, for takeoffs, specifies the route from the runway to the first waypoint

STAR

Standard Terminal Arrival, for landings, speciefies the route from the last waypoint down to the runway

TACAN

Tactical Air Navigation, military

TAF

Terminal Aerodrome Forecast

TAT

Total Air Temperature, this is derived by correcting the RAT for position. Still contains an error due to the compressibility of air inside the temperature probe.

TDZE

Touch Down Zone Elevation, the MSL of the touch down point of a runway

TOGA

Take-Off / Go-Around. Automatic single-switch operation of throttle for Take-off / Go-Around Power.

T&P(s)

Temperatures and pressures relating to engine systems.

UNICOM

Universal Communications. See also: CTAF

VOR

VHF Omnidirectional Range

VFR

Visual Flight Rules, 0-179: odd thousands+500ft, 180-359: even thousands+500ft

VNAV

Vertical Navigation,

A/P VASI

Visual Approach Slope Indicator, an approach lighting system, typically two lights left of the runway,

VORTAC

VHF Omni-Directional Range/Tactical Air Navigation, military

WCA

Wind Correction Angle