Aviation & Flight Terms Glossary is a general dictionary of flight related abbreviations, terms and phrases used in both general and commercial aviation.
AIR AMBULANCE Air charter of a private jet, helicopter or turbo-prop certified to provide air transport to medical patients.
AIR CHARTER Act of renting or leasing a jet or plane for transport of cargo or passengers.
AIR CHARTER AGENT One who is contracted on behalf of the end user of the charter flight. A charter agent works to ensure fair market value, reasonable safety measures are followed and to provide flexibility and options for the purchaser of the air charter flight.
AIR TRAFFIC CONTROLLER The service to pilots that promotes the safe, orderly and expeditious flow of air traffic. Usually each country operates its own Air Traffic Control service. In the UK, Air Traffic Control services are provided by NATS.
AIRCRAFT A machine used for flight which gains lift or support from the air.
AIRCRAFT INSURANCE Covers the operation of aircraft and the risks involved in aviation.
AIRPORT An area that is used for takeoffs and landings of aircrafts. Airports can be on land or water.
AIRSHOW: A cabin information system that displays the aircraft's position on a moving map, with altitude, time to destination, outside temperature and other flight data.
AIRSPEED Speed of an aircraft relative to its surrounding air mass.
AIRWAY DISTANCE Actual distance flown by the aircraft between two points (as opposed to straight line). Calculated after deviations required by Air Traffic Control and navigation along published routes.
ALTERNATE AIRPORT An airport other than the intended airport, where an aircraft can land for safety or other reasons.
ALTERNATE: Airport indicated on a flight plan where it is possible to divert the aircraft from its scheduled destination (in case of bad weather or any other major situation).
ALTIMETER SETTING: Barometric pressure reading in millibars (for example: 1015), or inches of mercury (for example: 29.80) used to set a pressure altimeter?s sub-scale toQFEorQNH.
ALTITUDE Vertical distance between an object and mean sea level.
AUGMENTED CREW: SeeHeavy Crew
AVGAS: Aviation Gasoline. Usually followed by the octane rating. Used by piston-engined aircraft.
AVIATION The operation, development, production and use of aircraft.
AVIONICS The electronic control systems airplanes use for flight such as communications, autopilots, and navigation.
AVTUR: Aviation Turbine fuel (kerosene). Used by turboprops and jet aircraft.
BASE: Base of operations or aHUBfor an airline. The base leg is also one of the many words describing the approach segments. SeeFinalfor a diagram.
BEECHCRAFT HAWKER Business jet aircraft built by Hawker Beechcraft Corporation (HBC) between 2006 and 2013.
BLACK BOX: Popular name given to either theCVRor theFDRused to investigate an accident.
BLEED AIR: Hot compressed air taken from turbine engines.
BLOCK FLYING TIME Time between an aircraft first moving from its parking place for the purpose of taking off until it comes to rest on the designated parking position and until all engines are stopped.
BLOCK HOURS: The advance purchase of a specific number of hours of flying time, to be flown as and when required.
BLOCK RATES Rate for scheduling significant amounts of air charter time in advance under a prearranged agreement.
BLOCK SPEED The average speed at which an aircraft covers a specific distance. Based on ?block-to block,? or ?door-to-door ? (gate-to-gate).
BOEING BUSINESS JET A series of Boeing airliners designed for the corporate jet market and seating between 25 and 50 passengers within a luxurious configuration.
BOMBARDIER A family of business jets.
BOMBARDIER GLOBAL EXPRESS A large cabin, ultra long range business jet manufactured by Bombardier Aerospace in Toronto, Ontario, Canada.
BUSINESS JET A smaller Commercial jet aircraft model, configured to transport smaller groups of people.
BUSINESS JET CHARTER An aircraft that is chartered for the purpose or use in business transportation.
CARBON CREDIT Key component of national and international emissions trading schemes. They provide a way to reduce greenhouse effect emissions on an industrial scale by capping total annual emissions and letting the market assign a monetary value to any shortfall through trading. Credits can be exchanged between businesses or bought and sold in international markets at the prevailing market price. Credits can be used to finance carbon reduction schemes between trading partners and around the world.
CARBON EMISSIONS The principal greenhouse gas emission. Carbon is largely thought to be the most dangerous greenhouse gas.
CARBON OFFSET Monetary contributions to renewable energy research and production projects, designed to reflect and mitigate the user's own greenhouse gas emissions eg through air travel.
CARDINAL ALTITUDE An altitude, or flight level, of a thousand feet.
CATERING A service provided for luxury jet charters. Catering is the provision of in-flight meals.
CEILING: Height above ground or water level of the base of the lowest layer of cloud, below 20,000 feet, covering more than half of the sky. Service ceiling also means an aircraft?sDENSITY ALTITUDEat which its maximum rate of climb is lower or equal to 100 feet per minute. The absolute celing is the highest altitude at which the aircraft can maintain level flight.
CESSNA An American general aviation aircraft manufacturing corporation headquartered in Wichita, Kan. Known for small, piston-powered aircraft, as well as business jets.
CHARTER BROKER: An individual or company that acts as a middle man between the charter operators and the charter passengers. A good broker will be able to find the best deal for his customer's needs.
CHARTER CARD Pre-paid air charter plan, either for a block of charter hours at a pre-defined fee, or a set debit balance in dollars.
CLEARANCE: Authorization given byATCto proceed as requested or instructed (for example: ?Cleared for take-off?, ?Cleared for visual approach?, ?Cleared to land?)
CLUB SEATING: A seating layout where pairs of seats face each other, as in a railway carriage compartment, rather than all face the same way, as on a bus. The club configuration is more sociable and enables easy conversation between occupants.
COAST TRACK: Status of an aircraft that is no longer giving a radar return. The air traffic control screen will display this status (usually with the acronym ?CST?) and will temporarily continue displaying the aircraft?s movement at the last heading and speed, as if it was ?coasting?.
COMMERCIAL FLIGHT A "commercial" flight is when the customer has paid for a commercial charter of that aircraft. The rules for commercial flights are more stringent than private flights and include limitations on crew duty hours, runway length and other safety considerations. For commercial private jet charter the minimum stopping distance for the aircraft is multiplied by 1.6, to create the minimum landing distance required (LDR).
COMMUTER OPERATOR A regional, scheduled airline. In this book limited to that operator with adequate fleet capacity as to be available of charter. Not all commuter airlines charter, because of the limitations of aircraft and crew availability.
CONNECTION: Transfer between two different flights at an intermediate airport (for example: flight 123 from New York to Miami followed by flight 456 from Miami to Sao Paulo). If a passenger?s flights are operated by two different airlines, they may check baggage or obtain boarding passes for the entire itinerary directly at the departure city?s airport, pursuant to interlining agreements or airline alliances. A connection is not the same as astopover.
CONTRAILS Streaks of condensed water vapour created in the air by aircraft flying at high altitudes; aka vapour trails.
CONTROLLED AIRSPACE Defined airspace where Air Traffic Control service is provided to IFR flights and to VFR flights.
CORPORATE OPERATOR A company flight department which has earned a "Part 135" certificate to carry passengers for compensation.
CROSSWIND Winds blowing perpendicular or not parallel to the runway or the aircrafts flight path.
CROSSWIND: Wind perpendicular to the motion of the aircraft. The crosswind leg is also one of the many words describing the approach segments. SeeFinalfor a diagram.
CRUISE SPEED The normal speed attained at altitude once the aircraft is no longer climbing and is en route.
CRUISING ALTITUDE A level altitude maintained by an aircraft while in flight.
DASSAULT FALCON A family of business jets manufactured by Dassault Aviation.
DEAD HEAD A leg of an air charter with no cargo or no passengers. Commonly the return leg, but may also be the repositioning.
DEAD LEG: Seeempty leg.
DECISION HEIGHT In an instrument approach flight, the height at which a decision must be made to either continue the approach or to execute a missed approach.
DEMURRAGE refers to the charges that are levied by an operator when a charterer keeps an aircraft after the completion of the flight. For example, if an aircraft is chartered for two flights with a week intervening, an aircraft may remain or lay over at the destination. The charterer will pay demurrage charges for every day that this aircraft remains at the charterer's destination without returning home.
DENSITY ALTITUDE: pressure altitude (as indicated by the altimeter) corrected for air temperature.
DEPRECIATION Method to account for assets whose value decrease over time because of factors such as age, wear or market conditions.
DIRECT FLIGHT: A flight that operates from point A to point B without aconnection. A direct flight is not necessarilynon-stop.
DME: Distance-Measuring Equipment. A combination of ground and airborne equipment which gives a continuous slant range distance-from-station readout by measuring time-lapse of a signal transmitted by the aircraft to the station and responded back. DMEs can also provide groundspeed and time-to-station readouts by differentiation.
DOUBLE ROUND TRIP Occurs when an air charter itinerary is designed such that it is more costly to keep the plane away from base than it would be to return home empty the report for pick up to complete the air charter itinerary.
DOWNWIND: One of the many words describing the approach segments. SeeFinalfor a diagram.
DUTY TIME A pilot or crew member is logging duty time whenever he is serving in any capacity. There are safety restrictions on duty time to ensure pilots and crew are sufficiently rested.
EMPTY LEGS A re-positioning flight where the aircraft is flying empty. Chartering an empty leg can cost significantly less than a full-price charter.
EXECUTIVE JET CHARTER An aircraft that is chartered for the purpose or use in the transportation of executives. Typically the aircrafts that are chartered are midsize jets.
FEATURED CHARTER FEATURED CHARTER The chartering of a specific aircraft to a specific destination. Featured charters often include hotel accommodations, luxury car rentals, golf and spa packages etc.
FERRY FLIGHT A flight for the purpose of returning an aircraft to base, delivering an aircraft from one location to another, moving an aircraft to and from a maintenance base.
FINAL: Final Approach. One of the many words describing the approach segments. The part of a landing sequence or aerodrome circuit procedure in which the aircraft has made its final turn and is inbound to the active runway. See picture on the right.
FLEET MANAGER A commercial aviation entity developed to subcontract the maintenance and operation of corporate aircraft, which are often chartered out to the general public.
FLIGHT ATTENDANT: A member of the crew dedicated to attending to the passengers during the flight. Often able to meet advance requests for specific catering, drinks, magazines, flowers or other requirements.
FLIGHT PLAN Filed with an Air Traffic Control Facility a flight plan is the specific information regarding the flight or intended flight of an aircraft.
FLIGHT TIME: The time between take-off and landing. Excludes any time spent taxiing to and from thestand.
FRACTIONAL OWNERSHIP The purchase of a "share" of an aircraft. Fractional owners are guaranteed access to an aircraft but not necessarily the same one each time. They usually pay a fixed monthly maintenance fee as well as an hourly fee.
FREEDOM OF THE AIR: Commercial aviation right governing carriage ofPAYLOADbetween or within countries. The following are recognized by theICAO:
FUEL SURCHARGE A charge for the increased price of fuel to cover fuel price increases.
FUSELAGE An aircraft's main body structure housing the flight crew, passengers, and cargo.
GAT: Abbreviation forGeneral AviationTerminal. TheHandling Agentswill often be located here as GA terminals are much quieter than scheduled terminals.
GENERAL AVIATION: The aviation industry categorises flights as eitherScheduled,Cargo,MilitaryorGeneral. Non-airline passenger flights fall in the broad General Aviation category, however the termsBusiness AviationorExecutive Aviationare frequently used to differentiate private jet charter flights from light aircraft enthusiast flights.
GO-AROUND: Balked approach, when the aircraft climbs away from the runway during the approach, to either start the approach again, or proceed to theALTERNATE AIRPORT.
GREAT CIRCLE DISTANCE The shortest distance between two points on a globe. All distances shown in distance tables in the Air Charter Guide are "great circle distance".
GROUND SPEED The speed of an aircraft relative to the surface of the earth.
GROUND TRANSPORTATION A service provided for luxury jet charters before or after the flight. Ground transportation can be limo service or luxury car rental.
GULFSTREAM Business jet aircraft designed and manufactured by Gulfstream Aerospace Corporation, a wholly owned subsidiary of General Dynamics. Gulfstream?s fleet consists of these models: G150, G280, G350, G450, G500, G550, and G650.
HANDLING AGENT: A company appointed by the operator to greet and ease their passengers' passage through an airport. Will typically feature a dedicated car park, VIP lounge, security and immigration liaison and baggage porterage.
HANGAR An enclosed structure for housing aircraft. Originated with lake-based floating homes of the original German Zeppelins in which they were "hung" from cables.
HEAVY CREW: Flying with one or more additional flight crew members. On occasion an ultra-long range aircraft might carry additional pilots to allow each to rest in rotation and counter the onset of fatigue.
HEAVY JET An aircraft with a minimum takeoff weight of 255,000 lbs.
HEAVY: Suffix used in radio transmissioncallsigns(for example: ?United 492 Heavy?) to indicate the aircraft is capable of generatingWAKE TURBULENCE.
HELICOPTER A rotor driven aircraft that uses vertical axes with pitched blades to generate lift and stability.
HELIPAD Used by helicopters for takeoffs, landings and occasionally for parking.
HELIPORT The area of land or water used for the landings and takeoffs of helicopters, the buildings, structures and grounds.
HOLDING PATTERN: Manoeuver consisting of making the aircraft turn around the aerodrome at an assigned altitude, while awaiting furtherATCinstructions.
INSTRUMENT APPROACH: An airport installation that enables the aircraft to safely land in poor visibility. All commercial airports and all but the smallest general aviation aerodromes have at least one instrument approach. A private jet charter can be arranged to any licensed airport or aerodrome with a runway sufficient for the aircraft.
INSTRUMENT METEROLOGICAL CONDITIONS Conditions such as visibility, distance between clouds, ceiling level that does not meet the standard for visual meteorological conditions.
INTERNATIONAL AIRPORT An airport designated to carry out the duties of customs and immigrations along with other duties.
JET AIRLINER An airliner that uses jet engine propulsion. Capable of efficiently functioning at a high altitudes and high speeds.
JET CARDS: Schemes by which operators sell individualsblock hourson their aircraft.
JET CHARTER Act of hiring crew; leasing an aircraft for the purpose of private air transportation.
JET CHARTER BROKER An intermediary who facilitates the leasing or purchasing of air charter. See also Private Jet Broker.
JET ENGINE An internal combustion air-breathing duct engine
JET STREAM High altitude, High Speed winds that in the United States blow from west to east.
JOINT OWNERSHIP Purchase or lease of a complete aircraft by a relatively small number of owners, often through a partnership or limited liability corporation.
KNOT (nautical mile per hour) Common measure of aircraft speed, equaling 6,080 feet or about 1.15 miles.
KNOT (KT): Standard unit of speed in aviation and marine transportation, equivalent to one nautical mile per hour. One knot equals 1.1515 mph, and one nautical mile equals 6,080 feet. The word ?knot? replaces ?nautical miles per hour?, and one should never say for example ?60 knots per hour?.
LAYOVER A rest stop away from home base for the aircraft and crew in the middle of a flight.
LEARJET A private luxury business jet aircraft originally manufactured by Learjet in Wichita, Kan. Now owned by Bombardier. The word is also used generically to refer to small business jets.
LEG A single direction of travel between two points. For an air charter itinerary a leg could be represented by repositioning and fuel stops.
LIFT Chartering an aircraft for cargo or passenger transport.
LOC: Localizer. The azimuth guidance portion of an instrument landing system.
LORAN: Long-Range low-frequency Radio Navigation. Its range is about 1,200 nm by day, and 2,300 nm by night.
LROPS: Long Range Operational Performance Standards. Certification intended to replaceETOPSas it would include all types of aircraft (not just twin-engine).
LUXURY JET CHARTER Chartering a luxuriously appointed aircraft for business or pleasure.These jets provide five-star catering, ground transportation, and lavish accommodations in excess of needs.
MACH NUMBER: Ratio of true airspeed to the speed of sound. Mach 1 is the speed of sound at sea level. Its value is approximately 760 mph.
MAGNETIC COURSE: Intended horizontal direction, measured in degrees clockwise from the magnetic north.
MANUFACTURER: Aircraft builder, such as Airbus, Boeing, Embraer, etc.
MATCH SPEED The ratio of true airspeed to the speed of sound
MAYDAY: The ultimate international radio distress call, indicating imminent danger to the life of the occupants onboard and requiring immediate assistance. Its slightly less prioritary equivalent isPan Pan. The anecdote says it comes from a French pilot who said over the radio ?Venez m?aider? (?help me?) to an English-speaking controller, who only understood ?Mayday?.
MEDEVAC MEDical EVACuation - the term commonly applied to an aircraft used to transport injured patients to hospital. See also Air Ambulance.
MID-SIZE JETS Aircraft designed for longer-range travel such as transcontinental flights. Provide larger passenger capacity.
MTOW: Maximum Take-Off Weight
NARA National Aircraft Resale Association
NATIONAL AIRSPACE SYSTEM The network of airspace, navigational services facilities and equipment.
NAUTICAL MILE Used to measure distances at sea. 2,025 yards or 6,076 feet.
NAVAIDS Navigational aid is any form of device that guides a pilot and his aircraft from one area to another. There are many different kinds of Navaids in use to provide guidance, location, and direction, the most popular being the Global Positioning System (GPS) but the term can also apply to a map, a beacon or a compass.
NAVAIDS Any type of device that guides an aircraft from one area to another. Examples include the Global Positioning System (GPS), a map, a beacon or a compass.
NAVIGATION Recording, planning and controlling the movement of an aircraft from one point to another.
NBAA National Business Aviation Association.
NM: Nautical Miles.
NON-REVENUE: Passenger flying free of charge, on aSTANDBYbasis, by presenting an airline/aviation employee pass. Non-Revenue passengers may or may not be on duty, therefore this expression also applies torepositioningcrew members. Also known as Non-Rev for short.
NON-STOP: A direct flight that operates from point A to point B without astopover.
NON-TOWERED AIRPORT An airport without a control tower
NO-SHOW: Passenger with a confirmed reservation, who failed to check-in or board on time.
NTSB: National Transportation Safety Board. A United States government organisation in charge of investigating in the case of an accident. In many countries, anAAIBfulfills that role.
ONE-WAYS The air charter of an aircraft for a particular leg of an existing air charter itinerary.
OPERATOR Responsible for the licensing, maintenance, safety and operations of one or more private charter aircraft. The operator is not always the owner of the luxury jet, business jet or private jet that is available for charter.
PAN PAN: International radio urgency call. It usually indicates a threat to the safety of an aircraft or its passengers. It is, however, less urgent thanMayday. Pan Pan comes from the French word ?Panne? which means ?failure?.
PATTERN The path of aircraft traffic around an airfield, at an established height and direction. At tower-controlled fields, Air Traffic Controllers supervise the pattern by radio (or in non-radio or emergency conditions by red and green light signals.
PAYLOAD: Revenue passengers and/or cargo, or more specifically their combined weight.
PHONETIC ALPHABET: Spelling technique under which each letter is replaced by a word starting with the letter in question (for example: ?Alfa, Bravo, Charlie? to spell ?ABC?). The current alphabet is also known as theICAO spelling alphabet, the international radiotelephony spelling alphabet or theNATOphonetic alphabet.
PILOT IN COMMAND The pilot responsible for safety and operations of the aircraft during flight.
POINT TO POINT PRICING Usually occurs when one charters a jet from a location other than where that aircraft is based; also known as a transient aircraft charter. Point to point pricing is typically the result of an empty leg being chartered for a portion of the primary routing of the original air charter itinerary.
POSITIONING When aircraft is ferried from its originating airport to another airport for departure.
POSITIONING FLIGHT: To fly an aircraftemptyto a particular airport in order for it to be able to commence a flight from that airport.
PRECIPITATION Water particles that fall from the atmosphere and reach the surface of the earth.
PREFFERED VENDORS The vendor of choice for supplemental lift. Air charter agents, jet charter brokers and charter jet operators compile a list of air charter vendors for each region that they service.
PRIVATE AIRPORT An airport used by general aviation and private aviation but is ineligible for use by scheduled airline travel.
PRIVATE FLIGHT An aircraft used by the owner, or one of their friends or family, for private use. No money changes hands, as versus a commercial flight.
PRIVATE JET An aircraft that is privately owned.
PRIVATE JET BROKER An intermediary who compares options from operators to facilitate selling or buying a private aircraft.
PRIVATE JET CHARTER Hiring a private jet aircraft for a specific itinerary - as opposed to ownership or fractional ownership of an aircraft.
PROHIBITED AREA An airspace area where flight is prohibited except by prior arrangement with the controlling agency.
RAMP The hard-surfaced space in front of an FBO or terminal facility, used for deplaning, parking of aircraft, etc.
RELEASE TIME A departure time restriction issued to a pilot by ATC (either directly or through an authorized relay) when necessary to separate a departing aircraft from other traffic.
REPOSITION: To undertake apositioning flight.
REPOSITIONING TIME The travel time for charter aircraft traveling to or from base en- route to the departure or from the destination of the particular air charter trip.
REPOSITIONING: Flying from the point of destination to the next point of origin, without carrying anyPAYLOAD(in the case of an aircraft) or without being responsible for payload (in the case of a crew member). Example: a scheduled U.S. airline operates a charter flight from Los Angeles to Lisbon. Then, payload-free, it flies to Paris, where it will board passengers and cargo for a scheduled flight back to Los Angeles. Also known as deadheading, ferry flight.
RESTRICTED AREA ?Active? or ?Hot? airspace that usually excludes civilian aircraft. May include airspace used for rocket flights, practice air-to-air combat or ground-based artillery practice. Temporary restricted areas are established for forest fires, natural disasters or major news stories. Flight through a restricted area may be authorized by the FAA.
REVENUE FLIGHT: Any flight that generates revenue for the operator. i.e. not apositioning, crew training or maintenance flight.
RUNWAY Hard surface, smooth area used for aircraft landings and takeoffs.
SCHEDULED AIR TRANSPORTATION Airline Transportation regulation for scehduled air service requiring the FAA Part 121 certificate.
SECTOR: Segment involving a take-off and landing (for example: a London-Bangkok-Sydney flight contains two sectors)
SEE AND AVOID The FAA requires all pilots to be responsible for keeping their aircraft separated from other aircraft when visual conditions permit spotting traffic. This also applies to IFR flights when pilots are operating in visual weather conditions, and to VFR flights being issued radar advisories.??SIGMET An advisory significant to the safety of ALL aircraft, usually issued in times of severe weather.
SMALL CABIN JETS: Private jets built primarily for efficiency and lower cost of operation. A good choice for business travel and still afford plenty of luxury on shorter journeys.Browse small cabin jets.
SOB: Souls (persons) On Board. Also POB, Persons on Board.
SPEED OF SOUND Equal to 761 mph at sea level. Also known as Mach 1.
SPORT JET CHARTER An aircraft chartered to transport members of sports teams to sporting events.
SQUAWK (TO): To transmit an assigned code via a transponder (for example: Delta 207 Heavy, Squawk 2044). The squawk is also the assigned code. Below are some standard special squawks:
STAGE LENGTH The distance of the air charter client's itinerary.
STAND: The part of the tarmac on which the aeroplanes stand when idle, separate from the taxiways and runways. Many airports allow private charter customers' cars to be escorted to and from the stand for transferring passengers and luggage. If preferred, or where airport regulations prohibit passenger vehicles airside, the handling agent will transfer passengers and luggage in their own vehicles.
STANDBY: In radio communications, is a word to ask the other person to wait for further instructions. A standby reservation is conditional and is on a waiting list, in case of anyNO-SHOWS.
STAND-UP CABIN: A cabin designed for sufficient height to allow passengers to move around the cabin with relative ease. Typically taken to be a ceiling height of 5'8" or greater.Browse jets with stand-up cabins
STATUTE MILE A unit of length equal to 5,280 feet.
STOL: Short Take-Off and Landing.
STOPOVER: Scheduled interruption of a flight at an intermediate airport, either to refuel (in which case, it is known as a ?technical stopover?) or to pick up/drop offPAYLOAD(for example: flight 789 from New York to Delhi, with a stopover in London). Unlike aconnection, a stopover usually does not involve a change of flight number or airline, but may involve a change of aircraft.
STOVL: Short Take-Off and Vertical Landing.
SUPER MID-SIZE JETS Combining transatlantic capability with the speed and comfort of a wide-body, high-altitude aircraft. Feature wide-body cabin space, high-altitude capability, speed and ultra-long range.
TAIL NUMBER The airplane?s registration number.
TAIL WIND Winds that come from behind the aircraft and provide additional air speed in flight.
TARMAC A paved airport surface including runways or aprons at an aircraft hangar.
TAS: True Airspeed. Rectified airspeed corrected for altitude and outside air temperature.
TAXI TIME The time the aircraft is in transit to the runway up to the point of take off.
TCA (Terminal Control Area) A volume of controlled airspace set up at the confluence of airways in the vicinity of one or more major airports to protect traffic climbing out from and descending into the airports.
TCAD This proprietary low cost anti-collision system detects and alers pilots to nearby transponders. However, it does not provide evasive instructions or coordinate with other aircraft.
TCAS: Traffic alert and Collision Avoidance System. U.S. developed radar-based airborne collision avoidance system operating independently of ground-based equipment. TCAS-I generates traffic advisories only, TCAS-II provides advisories and collision avoidance instructions in the vertical plane.
TECHNICAL STOP: Landing at an airport en-route to the destination airport for technical rather than operational reasons, most typically to upload fuel if the total journey exceeds the range of the aircraft.
THIRD PARTY VERIFICATION Refers to the verification of safety, maintenance and operations by an independent auditor.
TOGA: Take-off/Go Around. An autopilot setting activating take-off orGO-AROUNDthrust.
TOUCHDOWN: Synonym of landing. May also refer to a stopover that does not involve a change of aircraft or flight.
TRAFFIC PATTERN Based on a standard rectangular flight pattern around airport landing runways. May involve 45-degree or crosswind entry, with downwind, base and final legs as rectangle sides. 90-degree left turns are standard, while right-hand traffic patterns are considered non standard (noted in Airport Facility Directories). Downwind is usually flown at a 1,000 or 1,500 feet above the airport elevation. Those airports with a control tower may modify or short-cut the pattern under ATC instructions.
TRANSITION ALTITUDE (TA): Altitude in the vicinity of an aerodrome at or below which the vertical position of an aircraft is controlled by reference to altitude (with the aerodromeQNHset on its altimeter). Above transition altitudeQNEis set and flight levels used. Also called transition level (TL) at which a descending aircraft changes fromFLto QNH.
TRANSPONDER: Airborne receiver/transmitter portion of theSSRsystem which receives the interrogation signal from the ground and automatically replies according to mode and code selected. Modes A and B are used for identification, using a four-digit number allocated by air traffic control. Mode C gives automatic altitude readout from an encoding altimeter.
TRUE AIR SPEED The speed of an aircraft relative to the airmass in which it is flying.
TSB: Transportation Safety Board of Canada. Agency that investigates accidents, in a similar fashion to theNTSBin the United States or anAAIBin other countries.
TURBINE A vital component in jet engines, turbines use compressed air to generate thrust, and inside the motor, spin a metal shaft. Turbines also power turboprop aircraft.
TURBO JET AIRCRAFTS Aircrafts with jet engines that operate turbines which operate air compressors.
TURBO PROP AIRCRAFT An aircraft with turbine and propeller powered by a jet engine.
TURBO-PROP: An aircraft that has propellers driven by gas-turbine engines
UM: Unaccompanied Minor. Underage passenger (typically 5-15 years old) travelling without a parent, guardian or trusted adult. An UM is under the constant supervision of airline staff from the departure gate until he or she is picked up at the arrival airport.
UPWIND: One of the many words describing the approach segments. SeeFinalfor a diagram.
UTC: Greenwich Mean Time (GMT). The abbreviation is a compromise between the French language termTemps Universel Co-ordonn?and the English language equivalentUniversal Co-ordinated Time.
V/STOL: Vertical and Short Take-Off and Landing.
VISIBILITY The ability to see and identify prominent un-lit objects during the day and lit objects of prominence at night.
VISUAL METEROLOGICAL CONDITIONS The conditions in which pilots have enough visibility to fly an aircraft and maintain visual separation between clouds and a ceiling, terrain and other aircraft.
VLJ Very Light Jet (may also be referred to as entry-level jet) is a small, short-range and jet that can be operated by a single pilot and seats 2-4 passengers.
WAIT TIME The time the aircraft is waiting on the tarmac for the departure of its next leg of the itinerary.
WAKE TURBULENCE Turbulent air condition caused by small, tornado-like horizontal whirlwinds trailing an aircraft's wingtips (wingtip vortices). Wake turbulence associated with larger aircraft flying at slow speeds (as on take-off or landing approach) is the most severe and can cause loss of control for smaller aircraft following close behind. Controllers use defined separation standards to avoid the problem for take-off, landing, approach and departure operations.
WAYPOINT: Reference point used for navigation, usually indicated by latitude and longitude and sometimes altitude and typically used forGPSandINSnavigation.
WEATHER MINIMUMS The lowest?or worst?visibility conditions an aircraft may be legally flown under visual flight rules. Aircraft are required to fly under instrument flight rules, or not at all, when visibility is less than the specified minimums.
WINDSHEAR: localised change in wind speed and/or direction over a short distance, resulting in a tearing or shearing effect, usually at low altitude, that can cause a sudden loss of airspeed with occasionally disastrous results if encountered when taking-off or landing.
WINGLET Used to improve fuel economy; a small rudder-like addition placed on the tips of a wing used to stabilize, control or employ air movement, thereby increasing fuel economy..
ZULU TIME: UTC or Greenwich Mean Time (GMT). The aviation convention is to append the characters Z to times written as UTC and L to times written as local time. In the phonetic alphabet, Z is pronounced Zulu.