Posted on October 18, 2017
If you spend enough time hanging around Pilots or airplanes you’re bound to hear lots of acronyms such as ILS, OAT, MSA and a whole bunch more.
Whether you’re a student pilots, considering flights training, or just an all around aviation geek, here are some of the more common aviation acronyms, explained.
Who’s Who
ATC – Air Traffic Control
A service provided by a state’s aviation authority to promote the safe, orderly and expeditious flow of air traffic.
AO - Aircraft Operator
Organizations and people who own or operate the equipment, procedures and information used to support the aircraft’s overall missions
CFI - Certified Flight Instructor
A pilot who's certified by a states aviation authority to offer aircraft instruction
PIC - Pilot in Command
The pilot responsible for the control and operation of the aircraft during flight
SIC - Second in Command
The pilot who is designated to take over control of an aircraft under direction of the pilot in command
FBO - Fixed-Base Operator
Supplier of fuel, maintenance, flight training and other services at an airport
FSS - Flight Service Station
Facilities that provide pilot briefings and routine en-route communications
EFAS - En Route Flight Advisory Service
Technology that provides en route aircraft with flight updates and important weather alerts
GA - General Aviation
The portion of civil aviation that refers to flights other than military, scheduled airline and cargo flights
Operational Abbreviations
VFR - Visual Flight Rules
Guidelines governing flights flown solely by reference to visual cues
IFR - Instrument Flight Rules
Guidelines governing flights under conditions in which it’s not safe to fly using only visual references
VMC - Visual Meteorological Conditions
Weather conditions that allow for VFR
IMC - Instrument Meteorological Conditions
Weather conditions that require IFR
AVGAS - Aviation Gasoline
Piston aircraft fuel
MEL - Minimum Equipment List
A list of instruments, equipment and procedures necessary to pilot a specific aircraft
UNICOM - Universal Communication
A common radio frequency used at uncontrolled (non-tower) airports for local pilot communication
METAR - Meteorological Aerodrome Report
Weather conditions observed at an airport
ATD - Actual Time of Departure
The time a pilot takes off from an airstrip or airport
ETD - Estimated Time of Departure
The time a pilot plans to take off from an airstrip or airport
ATA - Actual Time of Arrival
The time a pilot lands at a destination
ETA - Estimated Time of Arrival
The time a pilot plans to land at a destination
ATIS - Automated Terminal Information Service
Continuous broadcast of vital information including wind direction, velocity, pressure readings and active runway assignments
AFM - Airplane Flight Manuals
Documents developed by the aircraft manufacturer and approved by a state’s aviation authority, containing information and instructions required to operate the aircraft
POH - Pilot's Operating Handbook
Document developed by the aircraft manufacturer containing the approved AFM
Instrumentation
A/C - Aircraft
Refers to an aircraft, not air-conditioning
ADI - Attitude Direction Indicator
An instrument that shows the aircraft's orientation relative to the horizon, shows the roll and pitch of the aircraft
DME - Distance Measuring Equipment
An instrument that measures slant range distance from a nav aid
ALT - Altimeter
An instrument that measures an aircraft's altitude
HDG - Heading
The direction the aircraft's nose is pointing
NAV - Navigation System
The aircraft's directional system
GPS - Global Positioning System
Satellite-based navigation information
VSI - Vertical Speed Indicator
An instrument that displays an aircraft's rate of climb or descent
OAT - Outside Air Temperature Gauge
An instrument that displays the temperature of the air immediately outside the aircraft
EHSI (or HSI) - Electronic Horizontal Situation Indicator
Combines a heading indicator instrument with course deviation indicator
VOR - VHF Omnidirectional Range
Short-range, ground-based radio navigation system for aircraft
A Few Common In-Flight Terms
CAS - Calibrated Airspeed
The indicated airspeed of an aircraft, corrected for position and instrument error
IAS - Indicated Airspeed
A direct instrument reading not corrected for position and instrument error
CAT - Clear Air Turbulence
Turbulent conditions absent of visual indicators such as clouds
CAVU - Ceiling and Visibility Unlimited
Ideal flying weather
AGL - Above Ground Level
Measurement of altitude above a specific land mass
MSL - Mean Sea Level
The average height off the surface of the sea for all stages of tide
ALS - Approach Light System
Lighting system on the approach end of the airport runway
AGR - Air-Ground Ranging
Straight-line distance from the aircraft to a point on the ground
