T
tab |noun| the hinged rear part of flight control surface used for trimming / Trim tabs remove the pilot’s control loads by aerodynamically holding the control surface in the required position. /
table |noun| a set of facts or figures displayed in columns and rows / Charts are issued at UK meteorological offices and show, for selected locations, a table of winds and temperatures at selected flight levels. /
tabular |adjective| - in tabular form > arranged in a table / The most widely acceptable presentation of fuel data is in tabular form but graphical presentations may also be used. /
Tacan |noun| an aircraft navigation system that uses UHF signals from a transmitting station for distance and bearing. Full form: Tactical area navigation aid
tachometer |noun| an instrument for the measurement of revolutions per minute of a rotating shaft / The pilot checks the tachometer and notes the resulting drop in r.p.m. for each magneto. /
TAF |abbreviation| 1. terminal aerodrome forecast 2. aerodrome forecast (ICAO); TAFs use a similar format and coding to METARs, but provide weather forecast information, rather than current weather reports, for a five-mile radius around a given point
tail |noun| the rear part of the aircraft / The tail section is the aft part of the fuselage to which is fitted the tail unit, comprising the tailplane, elevators, fins and rudders. /
tail assembly |noun| the aft part of the fuselage with the fin and rudder, tailplane and elevators attached
tail-dragger |noun| same as tail-wheel aircraft (informal)
tailpipe |noun| the exhaust section of the engine aft of the turbine
tailplane |noun| a horizontal stabilizer, a horizontal airfoil at the rear of the aircraft / On most high performance aircraft the incidence of the horizontal stabilizer (or tailplane) can be varied in flight. /
tail rotor |noun| a small rotor on the tail of a helicopter that prevents the helicopter from spinning in the direction opposite to the rotation of the main rotor
tail-skid |noun| a support or runner on the underside of the tail of an aircraft
tailspin |noun| a rapid and uncontrolled spiral descent of an aircraft
tail unit |noun| the rear part of the aircraft, usually consisting of the fin and tailplane
tail-wheel |noun| a small wheel under the tail of an aircraft.
tail-wheel aircraft |noun| aircraft with a small wheel at the tail instead of a nose-wheel. Also called: tail-dragger
tail-wheel conversion course |noun| a course which familiarizes qualified pilots with the differences in handling characteristics between nose-wheel and tail-wheel aircraft
tailwind |noun| a wind which is blowing in the same direction as the direction of movement or flight / Because of the tailwind, the flight took only six hours. /
take off |verb| to leave the ground / When flying speed is reached the airplane takes off. /
take-off, takeoff |noun| the procedure when an aircraft leaves the ground / The aircraft has to accelerate before take-off. There is a tendency for propeller driven aircraft to swing or yaw on take-off. / Abbreviation: TO, T/O
take-off point |noun| a position on the runway, beyond which an aircraft is traveling too fast to slow down again safely, and therefore must take off
take-off roll |noun| the process of accelerating down the runway in order to take off
take-off run |noun| the distance from the start of take-off to the point where the wheels leave the ground / Acceleration forces can be felt as the aircraft begins its take-off run. /
take-off weight |noun| the weight of an aircraft at take-off, made up of its empty weight, plus the weight of its passengers, their baggage, freight and fuel
take over |verb| to replace someone in the function they are performing / The next shift will take over at 18:00. /
talk down |verb| to give advice to a pilot by radio on how to land an aircraft
tan |abbreviation| tangent
tangent |noun| a straight line, curve or surface which meets another curve or curved surface at a point, but which, if extended, does not cut through at that point / The glide path is at a tangent to the runway. / Abbreviation: tan
tangential |adjective| positioned at a tangent to something else
tank |noun| a large container for storing fluid / An aluminum alloy fuel tank is housed in each wing. /
taper |verb| to reduce in thickness towards one end / Fuel flowing from the float chamber passes through a jet, in which is positioned a tapered needle valve. /
tapered wing |noun| a wing which becomes narrower in width from root to tip
target |noun| the indication shown on a radar screen resulting from a primary radar return or a radar beacon reply / In a secondary radar system, the target is active. /
tarmac |noun| the runway and taxiways of an airport / They were working fast to clear the snow from the tarmac. /
TAS |abbreviation| true airspeed
task |noun| a function or duty / Present day transport aircraft are required to fly accurately, in all weather, for long distances or long periods of time and, in order to carry out this task efficiently, an autopilot is used. / - task sharing > dividing the workload between crew or team members in a systematic and integrated way
taxi |verb| to move an aircraft along the ground under its own power before take-off or after landing / Light aircraft can be steered while taxiing via a direct link from rudder pedals to the nose-wheel. / (NOTE: taxies – taxiing – taxied; the US English is taxying.)
taxi location sign |noun| an airport sign which indicates the taxiway that an aircraft is currently on
taxiing |noun| the movement of an aircraft along the ground under its own power before take-off or after landing / The taxiing of tail-wheel aircraft is more difficult than nose-wheel aircraft. / (NOTE: The US spelling is also taxying.)
taxiway |noun| a tarmac surface connecting the ramp or apron with the runway
taxiway ending marking |noun| painted markings consisting of striped lines on the far end of an intersection indicating the end of a taxiway
TCA |abbreviation| terminal control area
TCAS |abbreviation| traffic alert and collision avoidance system
TCAS Advisory |noun| a message given by the Traffic Collision Avoidance System warning the crew of the presence of another aircraft with which there may be conflict; there are two levels of message: 1. Traffic Advisory (TA), which does not require immediate crew action, and 2. Resolution Advisory (RA) which does, and supersedes any ATC instruction.
TCAS Resolution Advisory |noun| an automatically-generated warning such as ‘descend, descend’ requiring immediate crew action
TCDS |abbreviation| type certificate data sheet
technical |adjective| 1. referring to mechanical subjects or applied sciences 2. referring to the mechanical, electrical, hydraulic or pneumatic systems of an aircraft / A technical problem with the aircraft prevented it from taking off on time. /
technical log |noun| a record of all technical incidents and maintenance action carried out on a given aircraft, signed by the crew and technicians and kept on the flight deck. Also called: log book
technique |noun| a special method for doing something / The preparation of charts is done by computer using numerical forecasting techniques. /
technology |noun| the study and use of the mechanical arts or applied sciences /The use of fly-by-wire in airliners was delayed to allow thorough development and encourage universal acceptance of the new technology./
TEHP |abbreviation| total equivalent horsepower
telemetry |noun| the work of recording and transmitting data about an object situated at a distance from the observer
TEMP |abbreviation| temperature
temperate |adjective| mild, not extreme / Cold air in temperate latitudes is usually unstable. /
temperature |noun| a measurement, in degrees, of the intensity of heat of a body / Ground temperature is the temperature recorded by a thermometer placed at ground level. The altitude and temperature of the tropopause are of concern to aircrew. /
temperature error |noun| the variation in pressure altitude caused by a deviation of temperature from ISA
tempo |noun| the speed of an activity / The flow of passengers to exits and tempo of evacuation will be influenced by the number of exits available. /
TEMPO |abbreviation| temporary (ICAO)
temporary |adjective| lasting for a short time, not permanent / The indicator ‘tempo’, followed by a 4-figure time group indicates a period of temporary fluctuations to the forecast meteorological conditions which may occur at any time during the period given. / Opposite: permanent
tend |verb| to be apt or inclined to do something more often than not / Depressions tend to move around large anticyclones following the circulation of wind. / - the weather tends to be wet in the UK in the winter > the weather is often, but not always, wet
tendency |noun| an inclination, situation or condition which occurs more often than not / There is a tendency for propeller-driven aircraft to swing or yaw on take-off. / - he has a tendency to be late > he is often late - he has a tendency to forget things > he is forgetful
tensile |adjective| referring to stretching or pulling out / Reinforced plastic may have to support a tensile load, a compressive load or a bending load. /
tensile load |noun| the load caused by forces acting in opposite directions away from each other
tensile strength |noun| the strength of a structure to resist forces pulling it apart from opposite directions
tensile stress |noun| the forces that try to pull a structure apart from opposite directions
tension |noun| a strained condition resulting from forces acting in opposition to each other / A rod which is bent is shortened or in compression on the inside of the bend and is stretched or in tension on the outside of the bend. /
term |noun| 1. a word or expression / The term ‘payload’ includes passengers, baggage and freight. / 2. a limited period of time - a 5 year term > a period of 5 years - in the long term > when considering a long period of time - short term forecast > a weather forecast for the next few hours only
terminal |adjective| referring to a limit or to a final point - |noun| 1. the departure and/or arrival building at an airport / The flight leaves from terminal three at Heathrow airport. / 2. an electrical connection point / The negative terminal of the battery is marked - . /
terminal aerodrome forecast |noun| the weather forecast for the area around an aerodrome / In terminal aerodrome forecasts, the height of the cloud base forecast is above airfield level unless otherwise stated. / Abbreviation: TAF (NOTE: TAFs are scheduled four times daily for 24-hour periods beginning at 0000Z, 0600Z, 1200Z, and 1800Z.)
terminal airfield |noun| the airfield at which a flight finishes
terminal area forecast |noun| the weather forecast for the area around an airport. Abbreviation: TAF
terminal control area |noun| an air traffic control area established at the meeting place of a number of routes near one or more major airports / In some areas where there is a local concentration of traffic, terminal control areas are set up. / Abbreviation: TCA, TMA
terminate |verb| to end, or to bring to a close / The flight terminates in New York. / - the transmission terminated abruptly > the transmission stopped suddenly and unexpectedly
terminology |noun| a set of words or expressions used for a particular subject / It is necessary to learn some of the terminology associated with aircraft navigation. /
terrain |noun| land, especially in relation to its physical geography / Special attention should be paid to wind flow when flights are made over hills or mountainous terrain. /
terrestrial |adjective| referring to the earth / Clear skies allow terrestrial radiation to escape. /
territory |noun| the extent of the surface of the Earth governed by a particular country, ruler, state, etc. / All places in the same territory, or part of the same territory, maintain a standard of time as laid down by the government responsible for that territory. /
tertiary |adjective| referring to something which is third in order of rank, behind primary and secondary / Tertiary radar systems are synonymous with long-range navigation aids. Tertiary structures, for example fairings, wheel doors and minor component brackets, are essential parts of the airframe. /
tertiary radar |noun| long-range navigation aids
test |noun| 1. a series of operations to find out if something is working well / The manual test for the engine fire warning system will give a steady red light on all the fire control handles. / 2. an examination to assess the knowledge of a person / There is a navigation test for students at 0800 hours. / - |verb| 1. to operate something in order to find out whether it functions correctly / Oxygen under pressure is used to test the oxygen masks and equipment for fit and leakage. / 2. to examine somebody in order to assess his or her knowledge / The students are tested in five subjects. /
test pilot |noun| a pilot who flies new aircraft in order to check their performance
TGT |abbreviation| turbine gas temperature
theory |noun| a system of ideas or principles explaining something / The theory of navigation must be studied before any practical plotting exercises are done. /
theory of flight |noun| the ideas and principles which contribute to our understanding of how things fly
thereafter |adverb| after that, beyond that / Meteorological visibility is given in meters up to 5,000 meters and thereafter in km (kilometers). /
thereby |adverb| by that means or in that way / The evacuation was carried out at a slower rate, thereby minimizing the risk of injury to passengers. /
therefore |adverb| as a result, consequently / At small throttle openings, the depression at the choke is very small and therefore no fuel flows from the main jet. /
thermal |adjective| referring to heat / Intense surface heating causes thermal currents to develop and create convection. / - |noun| a rising current of relatively warm air in the lower atmosphere / Glider pilots circle in thermals in order to gain height. /
thermal activity |noun| a period of time when there is a lot of vertical movement of air caused by heating / Cumulus clouds may develop because of thermal activity resulting from the warming of the surface. /
thermal barrier |noun| the heat caused by air friction on an aircraft flying at high speed
thermo- |prefix| heat
thermocouple |noun| a device for measuring temperature / Variation in temperature of the cooling air will give some indication of engine trouble through a thermocouple system to a temperature gauge. /
thermodynamic |adjective| referring to the conversion of one form of energy into another and how this affects temperature, pressure, volume, mechanical action and work
thermometer |noun| an instrument for measuring temperature / Ground temperature is the temperature recorded by a thermometer placed at ground level. /
thermoplastic |noun| a type of plastic which can be softened by heating then shaped, then softened again by heating
thermosetting plastic |noun| a type of plastic which is heated while being shaped but which cannot be softened by reheating /If a piece of thermosetting plastic is hit hard enough, it breaks into pieces with straight sharp edges./
thick |adjective| 1. of great or particular extent between two surfaces / This sheet of aluminum is not very thick. / 2. with a large diameter 3. dense / thick fog, thick cloud / 4. of a consistency which does not flow easily / thick oil / Opposite: thin
thickness |noun| 1. the extent between two surfaces / In monocoque construction, there is no internal stiffening because the thickness of the skin gives strength and stability. / 2. the extent of the diameter of a wire 3. the state or condition of being thick
thin |adjective| 1. of small extent between two surfaces / a thin layer of paint / 2. with a small diameter / thin wire / 3. not dense / Alto-stratus cloud is thin enough for the sun to be dimly visible. / 4. of a consistency which flows easily / thin oil / Opposite: thick
thinness |noun| 1. a small extent between two surfaces / The thinness of the material makes it unsuitable. / 2. a small extent of the diameter of a wire 3. the state or condition of being thin
thorough |adjective| complete / All cabin crew must have a thorough knowledge of fire fighting equipment and procedures. / - a thorough inspection > a very detailed, comprehensive inspection
THP |abbreviation| thrust horsepower
threat |noun| 1. a suggestion that something unpleasant or violent will happen / There is a threat of airport closures caused by the strike. / 2. a danger / Bird strikes remain a serious threat to aircraft safety. /
threaten |verb| 1. to give signs or warnings of harm or danger / Wind-shear can threaten the stability of aircraft on final approach. / 2. to force someone to act under duress / The terrorist is threatening the crew. /
three greens |noun| the green arrows or indicator lights on the landing gear display which indicate that the landing gear is extended and correctly locked down
three-letter group |noun| three letters of the alphabet found together
three-point landing |noun| an aircraft landing in which the two main wheels of the landing gear and the nose-wheel or tail-wheel touch the ground at the same time
threshold |noun| the beginning of the part of the runway, usable for landing / Runway visual range is obtained by an observer standing at the side of the runway in the vicinity of the threshold counting the number of markers or lights visible along the side of the runway. / (NOTE: The threshold is marked with a single white line on visual runways or by eight parallel white lines arranged longitudinally in two groups of four each side of the runway center-line for runways with instrument approach/landing facilities.)
throttle |noun| 1. a throttle lever 2. a throttle valve - |verb| - to throttle back > to reduce engine power / Throttle back to increase the rate of descent. / (NOTE: The verbs ‘open’ or ‘advance’ (= to increase engine power) and ‘close’ or ‘throttle back’ (= to decrease engine power) are frequently used by instructors to explain the required movement of the throttle lever in the cockpit.)
throttle lever |noun| a device operating the throttle valve / When starting an engine, it is inadvisable to pump the throttle lever because of the risk of fire. /
throttle quadrant |noun| an arc-shaped device in which the throttle levers move
throttle setting |noun| the particular position of the throttle which gives a required revolutions per minute or power
throttle valve |noun| a device controlling the flow of fuel in an engine
throughout |adverb| from the beginning to the end of a time or place / Emergency lighting is provided throughout the cabin. Heavy snow fell throughout the night. / - throughout the life of the aircraft > during the entire life of the aircraft - throughout the world > all over the world - throughout the year > from January 1st to December 31st
thrust |noun| a force produced by a propeller, jet or rocket / A propeller is a means of converting engine power into a propulsive force known as thrust. In order for the aircraft to increase speed, thrust must overcome drag. / - |verb| to push suddenly with force / A nozzle is an opening at the rear of a jet engine through which exhaust gases are thrust. / (NOTE: thrusting – thrust)
thrust horsepower |noun| the amount of horsepower of an engine that is transformed into thrust. Abbreviation: THP
thrust reversal |noun| setting of throttle levers to provide thrust in the opposite direction to decelerate the aircraft after landing
THS |abbreviation| Trimmable Horizontal Stabilizer
thud |noun| a deep, dull noise caused by an impact / The cabin crew heard a thud shortly before lift-off. /
thunder |noun| the noise created by the violent expansion and contraction of air momentarily heated by a lightning discharge / Thunder immediately following the flash of lightning usually indicates that the storm is overhead. /
thunderstorm |noun| a violent weather condition in which wind speeds increase, rain or hail falls and there is lightning activity / Thunderstorms occur in well-developed cumulonimbus clouds. The process of formation, development and decay of a thunderstorm. /
thunderstorm activity |noun| the occurrence of weather conditions associated with thunderstorms, such as rain, thunder, wind or lightning
thus |adverb| 1. in this way / This device fits with the other thus. / 2. therefore, as a result / The glide slope and localiser beam signals control the aircraft about the pitch and roll axes, thus maintaining alignment with the runway. Anti-skid braking systems are designed to prevent the brakes locking the wheels during landing, thus reducing the possibility of wheel skid. /
tie |noun| a basic structural member which is designed to withstand mainly tensile loads / Diagonal ties can be used to relieve tension and increase the effectiveness of the top boom. /
tight |adjective| closely or firmly fitting or put together - a tight fit > a situation when there is just about enough space to fit - |adverb| closely or firmly, with no air leaks / The door must be shut tight. /
tight circuit |noun| a traffic pattern turn with a short radius
tilt |noun| a sloping position / Land creates a drag effect on an electromagnetic wave-front, reducing the velocity of the wave thereby causing a tilt. / - |verb| to be at an angle to the vertical or horizontal, to slope / The Earth tilts on its axis. /
timely |adjective| at the right time / The controller made a timely decision and instructed the aircraft to climb immediately. /
timetable |noun| a printed list which shows the times of departure from and arrival to various destinations / All the scheduled flights are listed in the airline timetable. /
timetabled |adjective| listed in a timetable / A scheduled landing is an arrival at a timetabled destination. /
time zone |noun| one of the 24 parts of the Earth in which the same standard time is used
tip |noun| the end of a small or tapering thing
tire |noun| a rubber covering for a wheel
tire creep |noun| the gradual rotation of the tire in relation to the wheel, caused by landing / To convert magnetic bearing into true bearing it is necessary to apply magnetic variation at the point at which the bearing was taken. / (NOTE: Tire creep can lead to damage to the tire valve and subsequent unwanted and possibly dangerous deflation of the tire.)
tire pressure |noun| the air pressure in a tire / maximum allowable tire pressure /
titanium |noun| a light metal used to make strong alloys / The fatigue resistance of titanium is greater than that of aluminum or steel. /
TKOF |abbreviation| take off (ICAO)
TMA |abbreviation| terminal control area / Terminal Maneuvering Area
T/O, TO |abbreviation| take off
toggle |noun| a short piece of wood or other material, attached with a string to e.g. a life jacket / Pull the toggles downwards to inflate the life jacket. /
toilet |noun| 1. a bowl with a seat on which you sit to get rid of waste from your body 2. a room or cubicle with a toilet bowl in it / There are two toilets at the rear of the plane and one at the front. /
toilet service vehicle |noun| a vehicle with tank for emptying aircraft waste
tolerance |noun| an allowable variation in something which can be measured / a tolerance of 2°, a tolerance of 1mm (millimeter) /
tone |noun| a sound of one pitch / The ground transmits a code in two short bursts each of which is modulated with two tones. /
tool kit |noun| a set of tools consisting of spanners, screwdrivers, pliers, etc.
top |noun| the highest point or part / If cumulonimbus clouds cannot be avoided then flight through the top is less hazardous than through the center or bottom of the cloud. /
top-dead-center |noun| the position of the piston at the extreme top of its stroke in a piston engine / Ignition should occur just before top-dead-center. /
topic |noun| the subject of something heard, said, written or read / The first section in the book deals with the topic of airmanship. /
topographical |adjective| referring to topography / An advantage of using airfield QNH is that altimeter readings can be compared directly with heights represented on topographical maps. /
topography |noun| 1. a representation of detailed natural and man-made features of the Earth’s surface as represented on a map / The chart shows the topography of the area. / 2. relative elevations of the Earth’s surface, or features of a geographical area / The general circulation is complicated because the Earth tilts and its surface is neither level, because of topography, nor uniform due to areas of land and sea. /
torching |noun| flames coming from the engine exhaust duct due to the presence of fuel which has not been burnt
tornado |noun| a violent storm of small extent, with rotating winds /The winds of a tornado are of hurricane force./
torque |noun| a moment of forces causing rotation / Torque forces try to bend the propeller against the direction of rotation. High current flows through both the field and armature windings producing the high torque required for engine starting. /
torque-meter |noun| a device for measuring forces (torque) causing rotation / Engine torque is used to indicate the power that is developed by a turboprop engine and the indicator is known as a torque-meter. /
torsion |noun| twisting, especially of one end of a body while the other is fixed / Rivets are subjected to torsion and may break. /
torsion load |noun| the load caused by twisting of a structure
total |adjective| complete, whole / Of the total amount of radiation emitted by the sun, the Earth receives only a very small part. / - total system failure > complete system failure - total seating capacity > the maximum number of passengers who can be accommodated on seats
touch and go |noun| a training exercise by which pilots practice approaches, touch down on the runway, but do not roll out and stop
touch down |verb| to make controlled contact with the landing surface after a flight / If the atmospheric pressure at an airfield is 1,000 millibars (mb) and that pressure is set on the sub-scale of an aircraft altimeter, when the aircraft touches down at the airfield, the altimeter will read zero. /
touchdown |noun| the moment, after a flight, when the aircraft makes controlled contact with the landing surface / One of the aircraft’s tires burst on touchdown. /
touchdown aim point / target |noun| an area on runway materialized by white paint on which pilot intends to land
touchdown point |noun| the place on the runway where the aircraft undercarriage first touches the ground on landing
touchdown speed |noun| the airspeed at which the aircraft makes contact with the ground on landing / The touchdown speed of the B747 is approximately 160-170 knots. /
touchdown zone |noun| an area after threshold where aircraft usually touch down initially on landing
tow |verb| to pull an aircraft or vehicle using a bar, rope, etc. attached to another aircraft or vehicle / The glider was towed into the air by a Rollason Condor. /
tow-bar |noun| a bar connecting the aircraft nose gear to a tow vehicle for push-back and towing
tow vehicle |noun| a vehicle used especially during push-back to move an aircraft backwards from the stand or to pull it to another location at the airport. It is also referred to as a tug or tractor
tower |noun| a tall airport or airfield air traffic control building / One should always wait for permission from the tower before crossing an active runway. /
‘T’ piece adapter |noun| a device for connecting two inputs to one output or vice versa
track |noun| a projection on the Earth’s surface of the path of an aircraft, which can be expressed in degrees from north / Where an aircraft track and wind direction are the same, there will be a headwind component acting on the aircraft. The actual track does not necessarily follow the planned track and is given the name track made good. / - |verb| to follow a line of the flight path of an aircraft, as projected on the Earth surface / On final approach, track the imaginary extended center-line of the runway. /
tractor |noun| 1. an aircraft that has its propeller in front of its engine 2. a propeller in front of an aircraft engine, which has the effect of pulling the aircraft through the air 3. a towing vehicle, used especially during push-back, i.e. moving a plane backwards from the stand
trade winds |plural noun| steady winds which blow on the side of the sub-tropical highs nearest to the equator / Trade winds maintain their direction over the oceanic areas, especially the Pacific, more than over land areas. /
traffic |noun| the number of aircraft in operation / Standard instrument routes are structured to provide the safest and most efficient flow of traffic from entry and exit points to the airfield. /
Traffic Collision Avoidance System |noun| is a communication system between aircraft equipped with an appropriate transponder. Each TCAS-equipped aircraft “interrogates” all other aircraft in a determined range about their position, and all other TCAS-equipped aircraft reply to other interrogations. This interrogation-and-response cycle may occur several times per second. Through this constant back- and-forth communication, the TCAS system builds a three dimensional map of aircraft in the airspace, incorporating their bearing, altitude and range. Then, by extrapolating current range and altitude difference to anticipated future values, it determines if a potential collision threat exists. Abbreviation: TCAS
traffic conflict |noun| a state of traffic when two aircraft are at altitudes or on headings which, if maintained, could result in an airprox or a collision
traffic pattern |noun| 1. the shape marked out on the ground of an aircraft track in the aerodrome circuit 2. the pattern of routes that an aircraft must keep to when approaching or circling an airport
trailing |adjective| referring to something which comes after something else / The trailing brush is positioned behind the main brush on the rotor arm, thereby giving a retarded spark. /
trailing edge |noun| aft part of an airfoil / The trailing edge of the wing is the section behind the rear spar and is of light construction because the aerodynamic loads on this area are relatively low. /
train |verb| to teach a person a particular skill / The student pilot is trained to scan an instrument panel, whilst at the same time listening to the aircraft radio and flying the aircraft. / - |noun| a series of connected parts or wheels in machinery / The turboprop turbine transmits increased power forward through a shaft and a gear train, to drive the propeller. /
trainee |noun| a person who is being taught / a trainee pilot /
transducer |noun| a device which converts a non-electrical signal into an electrical one / The manifold is connected into the pressure ratio transmitter, which consists of a transducer, to sense the pressure ratio, and an associated electrical circuit, providing signals to the servo indicator in the cockpit. /
transfer |noun| the act of passing or moving to another place / External cooling of the engine is necessary to prevent the transfer of heat to the aircraft structure. / - |verb| to pass or to move to another place / It is sometimes necessary to transfer fuel from one tank to another tank. / (NOTE: transferring – transferred)
transform |verb| to change completely / The purpose of an actuator is to transform fluid flow into motion, i.e. it converts pressure energy into mechanical energy. Friction results in some of the power available from a pump being transformed into heat. /
transformer |noun| a device for changing the voltage or current amplitude of an alternating current signal / Current transformers differ from voltage transformers in that the primary circuit consists of a supply feeder cable rather than a coil connected across a supply. /
transient |adjective| passing or temporary, lasting only a short time / Transient loads can be absorbed by the busbar with a minimum of voltage fluctuations. / - transient parking > a place for planes to park temporarily
transit |noun| an act of moving - in transit > moving / A green light indicates the undercarriage is locked down, and a red light is displayed when the undercarriage is in transit. / - transit route > a route taken by one aircraft through controlled airspace
transition |noun| an act of passing from one place, state or condition to another
transition altitude |noun| altitude in the vicinity of an airport, at or below which the vertical position of the aircraft is controlled by reference to altitudes above mean sea level / When a flight takes place above the transition altitude, the standard pressure setting of 1013.25mb (millibars) is used. /
transition layer |noun| the airspace between the transition altitude and the transition level (NOTE: The depth of this layer will normally be insignificant and will never exceed 500 ft.)
transition level |noun| the flight level at which flight crews reset their altimeters from local atmospheric pressure (QNH or QFE) to standard atmospheric pressure at sea level (1013 hPa) and vice versa. Below this point altitude rather than level is used by pilots and controllers.
transit lounge |noun| a room where transit passengers wait for connecting flights
transit passenger |noun| a traveler who is changing from one aircraft to another
translation |noun| 1. the movement of an object in a straight line in which every part of the object follows a parallel course and no rotation takes place 2. the act of expressing the meaning of words in one language in words from another language
transmission |noun| 1. the sending of a radio signal / The combination of loop and sense antennae can determine the direction from which a transmission is made. / 2. a radio signal that is transmitted
transmit |verb| 1. to pass, to convey / As the camshaft rotates, the cam will transmit a lifting force through rods and pivots to open the valve. The charts are transmitted from one station to another by fax. / 2. to send out a radio signal / Survival beacons transmit a signal which enables search aircraft to rapidly locate survivors in the water. / (NOTE: transmitting – transmitted)
transmitter |noun| a device for sending out radio signals / Although continuous wave radars operate continuously, separate transmitter and receiver antennae must be used. Signal strength is inversely proportional to the distance from the transmitter. /
transparency |noun| the condition of being transparent / Meteorological visibility gives information on the transparency of the atmosphere to a stationary ground observer. /
transparent |adjective| allowing light to pass through so that things can be seen / Aircraft windows and canopies are usually made from transparent acrylic plastic. /
transponder |noun| a device in an aircraft for receiving a radio signal and automatically transmitting a different signal so that an air traffic control station can identify the aircraft / The transponder in the aircraft comprises a transmitter and a receiver. / (NOTE: The pilot sets an identification code, or ‘squawk’, assigned by ATC, on the transponder in the aircraft.)
transport |noun| a system for moving people, freight and baggage from one place to another / On a large transport aircraft, the safety of hundreds of passengers is involved. /
transport aircraft |noun| an aircraft designed to carry ten or more passengers or the equivalent cargo and having a maximum take-off weight greater than 5,670 kg
trap |verb| to catch and prevent from escaping / If there is a failure of the pressurized air supply, the check valve will close and trap pressurized air in the cabin. Smog is smoke or pollution trapped on the surface by an inversion of temperature with little or no wind. /
tread |noun| a series of patterns molded into the surface of a tire to provide grip / The risk of aquaplaning increases as the depth of tire tread is reduced. /
treat |verb| 1. to behave or act towards something or somebody in a particular way / Pilots should treat the engine carefully, if they want to prolong its life. / 2. to apply a process to something in order to get a particular result - treated water > water which has been made drinkable - heat-treated alloys > alloys which have undergone a process of hardening by using heat
treatment |noun| subjection to the action of a chemical or physical process / anti-corrosion treatment, heat treatment /
trembler |noun| an automatic vibrator for making and breaking an electrical circuit
trend |noun| 1. a general direction or tendency / Continuous VOLMET, which is normally broadcast on a designated VHF (very high frequency) channel, contains current aerodrome reports and trends where available. / 2. an up-to-date or modern way of doing things / Warning systems can take the form of lights, captions, and aural signals, and the modern trend is to incorporate them into a central warning system. /
triangle |noun| a plane figure with three sides and three angles / The triangle of velocities is a vector solution of what happens to an aircraft when wind causes drift. /
trigger |verb| to cause to operate, to set off / Normally, both the captain’s and first officer’s airspeed indicator trigger an aural warning if the airspeed limits are exceeded. /
tri-jet |noun| an aircraft powered by three jet engines
trim |noun| a condition in which an aircraft is in static balance in pitch / Trim indicators have a green band, to show when the trim is correct for take-off. / (NOTE: Some aircraft have rudder and aileron trim.) - |verb| to adjust trimmers in order to get the required hands-off pitch attitude / Trim the aircraft for level flight. /
trim fuel valve |noun| a valve which allows fuel to flow from the trim tank to the main fuel tanks in the wings and wing center box (between the wings)
trim tank |noun| an auxiliary fuel tank in the tail. Some long-range aircraft have fuel tanks in the horizontal stabilizer; the weight of this fuel is used to regulate the aircraft’s center of gravity (C.G.)
trim wheel, trimmer |noun| a wheel-shaped device, sometimes situated between the front seats of light aircraft, to trim the aircraft by hand / The trimmer is used to ease the loads imposed on the flying controls during flight. /
Trimmable Horizontal Stabilizer |noun| a horizontal surface mounted on the aircraft tail on which the elevators are installed; its angle can be adjusted to minimize drag and optimize aerodynamic efficiency. Abbreviation: THS
trip |verb| to cause an electrical device to suddenly stop working / Oscillating outputs from alternators could cause sensitive equipment to malfunction or trip. /
triplane |noun| an aircraft with three main wings fixed one above the other
triple |adjective| consisting of three parts / Probes may be of single, double or triple element construction. /
triple seven |noun| a Boeing 777 wide-body, twin engine, long-range jet airliner
tropical |adjective| referring to the area between the parallels of latitude 23° 26’ north and south of the equator /Tropical air moving northwards is subjected to surface cooling and becomes increasingly stable in its lower layers./
tropical storm |noun| a violent wind system which forms over tropical oceans / Tropical storms often dissipate when they pass from sea to land. /
tropics |noun| - the tropics > the area between the parallels of latitude 23° 26’ north and south of the equator / Throughout the tropics and sub-tropics, the sea breeze is a regular feature. /
tropopause |noun| the level at which the troposphere and the stratosphere meet / The altitude and temperature of the tropopause are of concern to aircrew because they affect aircraft performance. /
troposphere |noun| the lowest region of the atmosphere / The troposphere is at its deepest near the equator and shallowest near the poles. /
trough |noun| a long area of low barometric pressure / Severe icing and turbulence can be experienced when flying through a trough and the precipitation may be of hail, rain, snow or sleet. /
true |adjective| referring to a calculation or reading which has been corrected for errors
true airspeed |noun| airspeed corrected for instrument and position error in addition to altitude, temperature and compressibility errors
true altitude |noun| real or actual height above sea level
true bearing |noun| bearing with reference to true north, not magnetic north
true degrees |noun| degrees of direction measured from true north, not magnetic north. Also called: degrees true. Symbol °T
true north |noun| the direction towards north pole along a meridian through the observer
tube |noun| a long, hollow cylindrical device for holding or carrying fluids / A liquid-type fire detector consists of a tube and expansion chamber filled with liquid. /
tubing |noun| tubes in general
tubular |adjective| referring to something which is shaped like a tube / Diagonal members can be of angle section, box spar or tubular in shape. /
tug |noun| a towing vehicle, used especially during push-back. It is also referred to as a tractor or tow vehicle / We are waiting for the tug to arrive so that we can push back. /
tune |verb| 1. to set a system at its optimum point by careful adjustment / The engine has not been properly tuned. / 2. to adjust to the particular frequency of the required signal / The RBI shows the bearing of the tuned radio beacon with reference to the aircraft’s heading. /
tuner |noun| a part which allows the operator to select the particular frequency of the required signal / The tuner reduces interference. /
turbine |noun| a rotary motor or engine formed of a wheel driven by a flow of air or gas
turbo- |prefix| turbine
turbocharger |noun| a supercharger driven by a turbine powered by exhaust gases /The turbocharger significantly increases engine power./
turbofan |noun| a jet engine in which most of the thrust is produced by air, accelerated by a large fan, which does not pass through the combustion chamber of the engine / The Airbus A340 is powered by four CFM56 turbofans. / (NOTE: The US term is fan-jet. Turbofan engines are much quieter than older turbojets and make a characteristic sound when in operation. The fan can be clearly seen in the front part of the engine. Modern airliners use turbofan engines produced by major manufacturers such as Rolls Royce, CFM or Pratt and Whitney.)
turbojet |noun| a jet engine which includes a turbine-driven compressor for the air taken into the engine / The de Havilland Comet was the world’s first turbojet commercial transport aircraft. /
turboprop, turbo-propeller |noun| a turbojet engine in which the turbine also drives a propeller / The turboprop engine is often used in transport aircraft. / (NOTE: Turboprop aircraft are efficient at lower speeds than turbojet aircraft and are often used for short-haul operations.)
turbo-shaft |noun| an engine similar to a turboprop engine, except that it is used primarily in helicopters
turbulence |noun| an irregular motion of the atmosphere
turbulent |adjective| referring to the irregular motion of the atmosphere / When flying in turbulent air conditions, an aircraft is subjected to upward and downward gust loads. /
turn |noun| 1. an angular change in track / The autopilot may be engaged during a climb or descent but not usually in a turn. / 2. a section of a wire which is wound 360° around a center / The voltage in each winding is directly proportional to the number of turns in each winding. / - |verb| 1. to make an angular change in track / Turn to the west. / 2. to rotate / The crankshaft turns through 720° for every cycle of four strokes. / - turn the knob > rotate the knob or control 3. - to turn (in)to > to change state / As it descends into warmer air, snow turns into rain. / 4. to find a page, section, passage, etc., in a book / Turn to page 64. /
turnaround |noun| the time between the arrival of a flight at its parking stand and its departure for the next flight; it is a period when the flight crew’s attention is turned to a whole series of activities (servicing, unloading, loading, refuelling, catering, engineering, boarding etc.) where the airport ground staff is involved and contact with Air Traffic Control is limited. However, the flight crew also communicate with different categories of ground staff both by radio / interphone and face to face in situations where safety is an ongoing concern and the operational time constraints to depart on time create what is a potentially stressful environment. US same as turn-round
turn coordinator |noun| an instrument that shows the pilot if the aircraft is in coordinated flight or if it is slipping or skidding
turn off |verb| 1. to switch an electrical device or system ‘off’ / When carrying out engine checks, turn off the magnetos in turn to check their serviceability. / 2. to stop the flow of something by using a valve /Turn off the fuel./
turn on |verb| 1. to switch an electrical device or system ‘on’ / Can you turn the light on or turn on the light? / 2. to start the flow of something by using a valve / Turn on the fuel. /
turn-round |noun| unloading, loading and preparing an aircraft for another flight and the time taken to do this (NOTE: The word turnaround is preferred in US English.)
twin engine aircraft, twin-engined aircraft |noun| an aircraft with two identical engines
twist |verb| to turn against resistance / Centrifugal, bending and twisting forces act on a propeller during flight. /
TWR |abbreviation| aerodrome control tower
TWY |abbreviation| taxiway
type |noun| 1. a sort or kind / Temperature and oil pressure are critical to any type of system. / 2. a class of things having shared characteristics / The type of undercarriage fitted to an aircraft is governed by the operating weight. / - type of aircraft or aircraft type > all aircraft of the same basic design
type certificate |noun| a document issued by an aviation authority which indicates that the design of a certain aircraft, engine etc has been approved
type certificate data sheet |noun| a document associated with a type certificate, giving information about why the certificate has been granted and general information about the design which has been approved. Abbreviation: TCDS
type rating |noun| authorization, usually entered on a license, which allows the pilot to fly a particular aircraft type
typical |adjective| 1. normal, standard - a typical fuel system > a standard type of fuel system 2. representative of a particular class of things / The Piper Archer is a typical single-engine light aircraft. /
