Aviation Dictionary

Common definitions and acronyms that you may encounter during flying training.

List of aviation related definitions

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1013.2mb -  The standard pressure setting derived from the ISA which is used when the aircraft is flying at flight levels
121.500MHz -  Emergency frequency
7500 -  Transponder emergency code for unlawful interference
7600 -  Transponder emergency code for a radio communications failure
7700 -  Transponder emergency code for distress
AAIB -  Air Accident Investigation Branch
Aerial Work -  An aircraft operation such as agriculture, construction, photography, surveying, advertisement etc
Aerodrome -  A small airport or airfield
Aerodrome Flight Information Service (AFIS) -  Manned by a Flight Information Service Officer who can give information useful for the safe and efficient conduct of flights in the Aerodrome Traffic Zone (ATZ) and to give taxi instructions on the apron and manoeuvring area
Aerodrome Terminal Information Service (ATIS) -  Recorded broadcast of airfield and meteorological information
Aeronautical Information Circular (AIC) -  Aeronautical Information Circular. It is a notice containing information that does not qualify for the origination of a NOTAM or for inclusion in the AIP, but which relates to flight safety, air navigation, technical, administrative or legislative matters
Aeronautical Information Publication (AIP) -  The document in which operational aeronautical information is published
Aeronautical Information Service (AIS) -  The purpose is to ensure the flow of information necessary for the safety, regularity and efficiency of international air navigation
AFIS -  Aerodrome Flight Information Service
AGCS -  Air/Ground Communications Service
AGL -  Above Ground Level
AIC -  Aeronautical Information Circular
AIP -  Aeronautical Information Publication. Also know as the UK Air Pilot
Air -  A mixture of gases
Air Ground Communications Service (AGCS) -  The most basic type of ATSU which provides the pilot with basic aerodrome information, weather and any known traffic
Air Pilot -  Another term for the Aeronautical Information Publication (AIP)
Air Traffic -  All aircraft in flight or operating on the manoeuvring area of an aerodrome.
Air Traffic Control Service (ATCS) -  A service provided for the purpose of preventing collisions and maintaining an orderly flow of air traffic
Air Traffic Control Unit (ATCU) -  An air traffic service unit manned by licensed air traffic controllers who can issue instructions and advise to pilots. They may use callsigns Tower, Radar, Approach, Ground, Director or Control
Air Traffic Service Unit (ATSU) -  A generic term meaning air traffic control unit, flight information centre or air traffic services reporting office
Air Traffic Zone (ATZ) -  An airspace of defined dimensions established around an aerodrome for the protection of aerodrome traffic
Airprox -  Near Collision
Airway -  Control Area in the shape of a corridor along which IFR flights proceed in Class A airspace that are 10nm in width and extend from a notified lower level to a notified upper level
AIS -  Aeronautical Information Service
Alert Phase -  In search and rescue, a situation where apprehension exists regarding the safety of an aircraft and its occupants
Alternate Aerodrome -  An aerodrome to which an aircraft may proceed to land at if the planned aerodrome is not operational or not advisable to proceed with
Alveoli -  Tiny sacs within our lungs that allow oxygen and carbon dioxide to move between the lungs and bloodstream
AME -  Aviation Medical Examiner
AMSL -  Above Mean Sea Level
ANO -  Air Navigation Order
Anti-Collision Lights -  Flashing white lights on the wingtips
Apron -  Part of an aerodrome where aircraft can load passengers, fuel and park
Apron Stand -  Aircraft parking stand
ASI -  Airspeed Indicator
ASR -  Altimeter Setting Region
ATCS -  Air Traffic Control Service
ATIS -  Aerodrome Terminal Information Service
Atmosphere -  The layer of gases surrounding the Earth
ATZ -  An airspace of defined dimensions established around an aerodrome for the protection of aerodrome traffic
Barometer -  A device which measures the change in pressure.
Barotrauma -  A condition that causes ear discomfort due to pressure changes
BMI -  A measure of whether you're a healthy weight for your height
Bronchi -  Plural of bronchus. The trachea divides into a right and left main bronchus which conducts are into the lungs
Bronchiole -  The tiny branch of air tubes within the lungs that is a continuation of the bronchus. The bronchioles connect to the alveoli (air sacs)
Bronchus -  The trachea divides into a right and left main bronchus which conducts are into the lungs. Plural is bronchi
C of A -  Certificate of Airworthiness
C of R -  Certificate of Registration
CAA -  Civil Aviation Authority
Capillary -  Smallest of a body's blood vessels responsible for the delivery of essential nutrients directly to tissues throughout the body
Cellular Respiration -  The process of oxygen use and carbon dioxide production at the cellular level
Centre of Gravity -  The point at which weight is evenly dispersed and all sides are in balance
Certificate of Airworthiness (C of A) -  A certificate issued for an aircraft in the state in which the aircraft is registered.
Certificate of Registration (C of R) -  Legal document issued as part of an aircraft's documentation
CG -  Centre of Gravity
Circadian Rhythm -  The 24 hour cycle in the physiological processes of living beings
Clearway -  The area beyond the paved runway free of obstructions
Cochlea -  A small, curled tube in the inner ear filled with liquid
Commercial Air Transport Operation -  An operation involving the transport of passengers, cargo or male for remuneration
Cones -  Sensitive to bright light conditions
Control Area (CTA) -  Controlled airspace extending upwards from a specified lower limit above the earth to a specified upper limit. It can be Class A, D or E airspace
Control Zone (CTZ) -  Controlled airspace which extends from the surface to a specified upper limit, established to protect air traffic operating to and from that airport
Controlled Airspace -  Classes A, B, C, D and E
Cornea -  The outer covering of the eyeball
CTA -  Control Area. A controlled airspace extending upwards from a specified lower limit above the earth to a specified upper limit. It can be Class A, D or E airspace
CTR -  Control Zone. Controlled airspace which extends from the surface to a specified upper limit, established to protect air traffic operating to and from that airport. It may be Class A or D airspace
Danger Area -  An area that extends to a specified altitude in which activities dangerous to aircraft take place at certain times
Dangerous Goods -  Articles or substances that have the potential pose great risk to health, safety or operation of an aircraft when transported by air.
Decompression Sickness -  A condition in which nitrogen dissolved in the blood and tissues by high pressure forms bubbles as pressure decreases
Distress -  A situation in which the aircraft is threatened by grave and imminent danger, requiring immediate assistance
Distress Phase -  In search and rescue, a situation where there is reasonable certainty that aircraft and its occupants are threatened by grave and imminent danger and/or require immediate assistance
Ditching -  Forced landing of an aircraft on water
Downburst -  Also called Microburst. A sudden downward burst of wind from the base of a thunderstorm
Ear Canal -  Part of the outer ear
Ear Drum -  Beginning of the middle ear which vibrates due to pressure from sound waves
EASA -  European Aviation Safety Agency. This was formerly Joint Aviation Authority (JAA)
EDA -  Emergency Distance Available. EDA = TORA + Stopway
Emergency Phase -  Generic term covering an uncertainty, alert or distress phase in search and rescue
Eustachian Tube -  Found in the middle ear, its function is to equalise the air pressure on both sides of the eardrum, ensuring that pressure does not build up in the ear.
External Respiration -  Gas exchange between blood and air
FL -  Flight Level
Flight Crew Member -  A licensed crew member charged with duties essential to the operation of an aircraft.
Flight Level (FL) -  The vertical position of the aircraft when the International Standard Atmosphere (ISA) sea level pressure of 1013.2mb is used
Flight Plan -  A document which provides detailed information about a planned flight
Flight Time -  The time between the first moment an aircraft moved under its own power to until it comes to rest at the end of the flight.
Flight Visibility -  The visibility forward from the cockpit of an aircraft
Fovea -  The part of the retina that the light rays are focused on
FRTOL -  Flight Radiotelephony Operator’s Licence
Gastroenteritis -  An infection of the bowel sometimes called a 'tummy bug'
Haemoglobin -  A protein molecule in red blood cells that carries oxygen from the lungs to the body's tissues and returns carbon dioxide from the tissues back to the lungs
hPa -  Hectopascal. This is equal to 1 millibar
Human Error -  A failure of a planned action to achieve a desired outcome
Hyperventilation -  Excessive ventilation of the lungs, beyond what is required to achieve normal arterial blood gases (overbreathing)
Hypoxia -  A condition where the tissues of the body are not adequately oxygenated
ICAO -  International Civil Aviation Organisation
Incident -  An occurrence other than an accident, associated with the operation of an aircraft which could affect the safety of operation
Inner Ear - 
Has two divisions: one for hearing (consists of the cochlea), the other for balance (vestibular system)
Internal Respiration -  Gas exchange between the blood and body cells
IR -  Instrument Rating
Iris -  Regulates the amount of light entering the eye
ISA -  International Standard Atmosphere
Landing Light -  Light operated during the take-off , landing phases and low level flying for collision avoidance
LAPL -  Light Aircraft Pilot’s Licence
LDA -  Landing Distance Available
Lens -  Part of the eye that bends light rays
Licensed Aerodrome -  An aerodrome where flights for the purpose of the commercial air transport of passengers or the public transport of passengers, and/or flying training in aircraft above specified maximum total weights authorised take place
Manoeuvering Area -  The part of an aerodrome to be used for the takeoff, landing and taxiing of aircraft, excluding aprons.
mb -  Millibar. Unit of pressure
Mean Sea Level (MSL) -  The reference level from which a datum is measured.
MEP -  Multi Engine Piston
Microburst -  A sudden downward burst of wind from the base of a thunderstorm
Middle Ear -  The part of the ear that transmits sound from the outer ear to the inner ear
Movement Area -  The part of an aerodrome to be used for the takeoff, landing and taxiing of aircraft, consisting of the manoeuvring area and the apron.
MSL -  Mean Sea Level
MTWA -  Maximum Total Weight Authorised
Myopia -  Nearsightedness
Navigation Lights -  Green, red and white lights for collision avoidance at night. Green and red lights are on the right (starboard) and left (port) wingtips (respectively) and the white light is placed on the rear of the aircraft
Night -  The period between half an hour after sunset until half an hour before sunrise (ANO definition). The hours between the end of civil and the beginning of morning civil twilight (ICAO definition)
NOTAM -  Notice To Airmen. Details changes in the AIP
Notified Danger Area -  A danger area inactive unless notified by NOTAM
PAPI -  Precision Approach Path Indicator
Peripheral Vision -  The part of our vision that is outside the centre of our gaze
PIC -  Pilot In Command
Pilot In Command -  Pilot responsible for the operation and safety of the aircraft during flight time.
Pinna -  Ear flap (outer ear)
PoB -  People on Board
POH/FM -  Pilot’s Operating Handbook/Flight Manual
Port -  Left
PPL -  Private Pilot’s Licence
PPR -  Prior Permission Required
Presbyopia -  Long sightedness
Prohibited Area -  An area extending from ground level to a specified altitude. Flight within this area is prohibited
QFE -  Pressure setting that reads HEIGHT on the altimeter, usually above aerodrome level
QNH -  Pressure setting that reads ALTITUDE on the altimeter above mean sea level
Quadrantal Rule -  Flights outside controlled airspace are required to adopt this rule when flying above the transition altitude and below FL245
RCC -  Rescue Coordination Centre
Rescue Coordination Centre -  Unit responsible for promoting the efficient organisation of a search and rescue service within a search and rescue region
Respiration -  The process of gas exchange between the atmosphere and body cells
Restricted Area -  An area extending to an altitude in which flight is restricted under certain conditions
Rods -  Sensitive to low light conditions
Scheduled Danger Area -  A danger area active during published hours
Search and Rescue Region -  An area of defined dimensions within which a search and rescue service is provided
Semi-Circular Rule -  Above FL245 in uncontrolled airspace, flights are required to follow the semi-circular rule
Semicircular Canals -  Three small loops above the cochlea filled with liquid used for balance
SEP -  Single Engine Piston
Serious Incident -  An incident involving circumstances indicating that an accident nearly occurred
Spatial Disorientation -  The inability of a pilot to correctly interpret aircraft attitude, altitude or airspeed in relation to the Earth or other points of reference
Spatial Orientation - 
Defines our natural ability to maintain our body orientation and/or posture in relation to the surrounding environment (physical space) at rest and during motion
Standard Pressure -  1013.2mb is the pressure setting derived from the ISA and is the pressure setting used when the aircraft is flying at flight levels
Starboard -  Right
Stopway -  The area beyond the runway which can be used for deceleration in the event of a rejected take-off. It is centred upon the runway extended centreline and capable of supporting the aeroplane during an aborted take-off without causing structural damage to the aircraft.
Terminal Control Area (TMA) -  Class A airspace established where several routes merge in the vicinity of airfields
TMA -  Terminal Control Area. Class A airspace established where several routes merge in the vicinity of airfields
TODA -  Take-Off Distance Available. TODA = TORA + Clearway
TORA -  Take-Off Run Available. Length of the runway available for the take-off run
Trachea -  A wide, hollow tube that connects the larynx (or voice box) to the bronchi of the lungs. The function is to carry air in and out of the lungs. Also called the windpipe
Transition Altitude -  Altitude above which the altimeter can be set to the standard pressure setting of 1013mb to read Flight Levels. In the UK, the standard transition altitude is 3000ft outside controlled airspace
Transition Layer -  The area between the transition altitude and transition level.
Transition Level -  The lowest flight level above the transition altitude
Uncertainty Phase -  A situation where uncertainty exists regarding the safety of an aircraft and its occupants
Uncontrolled Airspace -  Classes F and G
VASI -  Visual Approach Slope Indicator
Ventilation -  Movement of air into the lungs
Vestibular System -  Part of the inner ear used for balance
Visual Acuity -  The ability to resolve detail
Visual Flight Rules (VFR) -  Being able to navigate, control the aircraft and avoid collisions just by looking out of the window. This is only possible in adequate weather, VMC
Visual Meteorological Conditions (VMC) -  The minimum conditions of weather expressed in terms of visibility and cloud ceiling in order to fly VFR  
VMC -  Visual Meteorological Conditions
Windpipe -  Another term for the trachea