The ABCs of Aviation

From the very first lesson, student pilots are introduced to a new and foreign language-the language of aviation. This new language is filled with terms and acronyms based on ideas that are far outside the normal experiences of most people. And like all languages, the language of aviation has a large and varied vocabulary.

Only minutes after strapping themselves into the airplane for an introductory flight, students will hear the instructor explain the need to get information from the ATIS (automatic terminal informational service). If a student's first flight is being conducted at a small nontowered airport, the instructor will announce the airplane's position on the field using the airport's CTAF (common traffic advisory frequency), and that is just the beginning. From here on, new pilots will consult the AIM (Aeronautical Information Manual) and FARs (federal aviation regulations), get advice from their CFIs (certificated flight instructors), land with the guidance of the airport's PAPI or VASI (precision approach path indicator or visual approach slope indicator), and report their altitude with reference to msl (mean sea level). On their journey toward a pilot certificate, they will use scores of such acronyms and abbreviations. They will become fluent in this new language.

What follows is a list of the abbreviations and acronyms that pilots will use most frequently throughout their flying experiences. When an asterisk (*) is used, it indicates a term that relates mostly to flight under IFR (instrument flight rules), but that is likely to be heard by all pilots.

The seemingly endless catalogue of military- and airline-specific terms has been omitted. Even so, pilots who land a career with the airlines, the military, or any other specialized area of aviation also will use the listed terms in their aviation operations. After all, seasoned Boeing 747 captains use the PTT (push-to-talk) button on the yoke to talk to the tower in the same way that student pilots flying Cessnas or Pipers do. Navy F-14 pilots are just as concerned with their ETE (estimated time en route) as pilots who are making their first solo cross-country flight.

AAF Army Airfield

ADF Automatic Direction Finder

ADIZ Air Defense Identification Zone

AFB Air Force Base

A/FD Airport/Facility Directory

AGL Above Ground Level

AIM Aeronautical Information Manual

Airmet Airmen's Meteorological Information

ATC Air Traffic Control

ALS* Approach Light System

AMEL Airplane Multiengine, Land

ARTCC Air Route Traffic Control Center

ASEL Airplane Single Engine, Land

ASOS Automated Surface Observation System

ASR* Airport Surveillance Radar

ATIS Automatic Terminal Information Service

ATP Airline Transport Pilot

AWOS Automated Weather Observation System

CAS Calibrated Airspeed

CAT Clear Air Turbulence

CFI Certificated Flight Instructor

CFII Certificated Flight Instructor, Instrument

CG Center of Gravity

CT Control Tower

CTAF Common Traffic Advisory Frequency

CWA Center Weather Advisory

DF Direction Finder

DH* Decision Height

DME Distance Measuring Equipment

DVFR Defense Visual Flight Rules

EAS Equivalent Airspeed

EFAS En Route Flight Advisory Service

EFC* Expect Further Clearance

ELT Emergency Locator Transmitter

ESA Emergency Safe Altitude

ETA Estimated Time of Arrival

ETE Estimated Time En Route

FAA Federal Aviation Administration

FAF* Final Approach Fix

FBO Fixed-Base Operator

FDC Flight Data Center

FIR Flight Information Region

FL Flight Level

FSDO Flight Standards District Office

FSS Flight Service Station

GADO General Aviation District Office

GPS Global Positioning System

GS* Glideslope

HAA* Height Above Airport

HAT* Height Above Touchdown

HIRL High Intensity Runway Light

HIWAS Hazardous In-flight Weather Advisory Service

HSI Horizontal Situation Indicator

IAF* Initial Approach Fix

IAP* Instrument Approach Procedure

IAS Indicated Airspeed

ICAO International Civil Aviation Organization

IFR Instrument Flight Rules

ILS* Instrument Landing System

IM* Inner Marker

IMC Instrument Meteorological Conditions

KIAS Knots Indicated Airspeed

KTAS Knots True Airspeed

LAA Local Airport Advisory

LAHSO Land And Hold Short Operations

LDA* Localizer Type Directional Aid

LMM* Locator Middle Marker

LOM* Locator Outer Marker

MAA* Maximum Authorized Altitude

MALS Medium-Intensity Approach Light System

MAP* Missed Approach Point

MC Magnetic Course

MCA* Minimum Crossing Altitude

MDA* Minimum Descent Altitude

MEA* Minimum En Route Altitude

MEF Maximum Elevation Figure

MEI Multiengine Instructor

MHA* Minimum Holding Altitude

MM* Middle Marker

MOA Military Operations Area

MOCA* Minimum Obstruction Clearance Altitude

MRA Minimum Reception Altitude

MSA* Minimum Safe Altitude

MSL Mean Sea Level

MTR Military Training Route

MVA* Minimum Vectoring Altitude

NAS National Airspace System or Naval Air Station

Navaid Navigation Aid

NDB Nondirectional Radio Beacon

NDB-DME Nondirectional Beacon with Distance Measuring Equipment

NFDC National Flight Data Center

NORDO No Radio Aircraft

Notam Notice To Airmen

NSA National Security Area

ODALS Omnidirectional Approach Lighting System

OM Outer Marker

PAPI Precision Approach Path Indicator

PAR* Precision Approach Radar

Patwas Pilot's Automatic Telephone Weather Answering Service

PIC Pilot In Command

Pirep Pilot Weather Report

POH Pilot's Operating Handbook

PT* Procedure Turn

PTS Practical Test Standards

PTT Push To Talk

RADAR Radio Detection And Ranging

RAIL Runway Alignment Indicator Light

Rarep Radar Weather Report

RCLM Runway Centerline Marking

RCLS Runway Centerline Light System

RCO Remote Communications Outlet

REIL Runway End Identifier Lights

RMI* Radio Magnetic Indicator

RNAV Area Navigation

RVR* Runway Visual Range

RVV* Runway Visibility Value

SAR Search And Rescue

SDF* Simplified Directional Facility

SFC Surface

SIC Second In Command

SID* Standard Instrument Departure

Sigmet Significant Meteorological Information

STAR* Standard Terminal Arrival Route

STOL Short Takeoff and Landing

SVFR Special Visual Flight Rules

TACAN Tactical Air Navigation Aid

TAS True Airspeed

TC True Course

TCH* Threshold Crossing Height

TDZE* Touchdown Zone Elevation

TDZL* Touchdown Zone Lights

TEC* Tower En Route Control

TIBS Telephone Information Briefing Service

TPA Traffic Pattern Altitude

TRSA Terminal Radar Service Area

TWEB Transcribed Weather Broadcast

Unicom Universal Communication

UTC Universal Time Coordinated

VASI Visual Approach Slope Indicator

VDP* Visual Descent Point

VFR Visual Flight Rules

VHF Very High Frequency

VMC Visual Meteorological Conditions

VOR VHF Omni Range

VOR-DME VHF Omni Range with Distance Measuring Equipment

Vortac VHF Omni Range/Tactical Air Navigation

VTOL Vertical Takeoff and Landing

WCA Wind Correction Angle

Although they may seem mystifying at first, these terms, abbreviations, and acronyms make the communications between pilots and controllers, as well as between pilots themselves, faster, clearer, and safer.