acronymnoun a word which is made up of the initial letters of a name, and is pronounced as a word o NASA is the acronym for National Aeronautics and Space Administration. o VASI is the acronym for visual approach slope indicator. actverb 1. to behave in a particular way o The crew must act with authority. 2. to take the role of o Mountain ranges act as a barrier. o The governor spill valve also acts as a safety relief valve. 3. □ to act on to produce an effect o Bending and twisting forces act on a propeller. o Gravity acts vertically downwards.
actingadjective temporarily taking on the responsibilities of somebody o Captain Smith will be acting Chief Flying Instructor while Captain White is absent from work. actionnoun 1. something done or to be done □ to take action to so something o If there is a risk of collision, the crew should take the appropriate action. 2. an effect activateverb to make a system or a piece of equipment or a procedure start to work or to operate o The system is activated by the pilot or copilot. o The sounding of the alarm will activate emergency procedures. activationnoun the act of making something start to work or to operate o Activation may be mechanical or electrical.
activeadjective 1. live, in action or use □ the system is active the system is on and working 2. not passive □ in a secondary radar system, the target is active in a secondary radar system the target transmits a signal while in a primary radar system it does not 3. □ active Cb clouds developing cumulonimbus clouds
active runway noun a runway that is being used ‘.. .never cross an active runway without permission from the tower: there may be more than one active runway’ [Civil Aviation Authority, General Aviation Safety Sense Leaflet]
actualadjective real The actual path of the aircraft over the ground is called its track, which may not be the same as the desired course. actuallyadverb in fact, in reality o The design is such that,although the aircraft loses altitude rapidly, it does not actually stall. actuateverb 1. to move a device or a part o The fore and aft movement of the control column actuates the elevators. 2. to switch on a system or a piece of equipment, or put it into operation o A lever actuates the fire deluge system. 3. to put a procedure into action o Receipt of the distress signal will actuate the support facilities at the airport.
actuationnoun 1. the act of making a device or a part move □ electrical actuation the use of an electric motor to make something move □ mechanical actuation the use of a mechanical part such as a rod, arm or lever to make something move 2. a movement made by a device or part actuatornoun a device which changes electrical or hydraulic energy into mechanical motion o The actuator control is sensitive to engine rpm. o Actuators are classified as either linear or rotary.
AD abbreviation airworthiness directive
A/D abbreviation aerodrome ADA abbreviation advisory airspace adaptverb 1. to change or modify for special use o The turboprop engine is often used in transport aircraft and can be adaptedfor use in single-engine aircraft. 2. to change to suit new conditions o Crew flying long-haul routes have to adapt to time changes.
adaptationnoun 1. the act of changing or modifying something for special use o Doppler VOR is an adaptation of VOR to reduce errors caused by location. 2. adjustment to new conditions o Adaptation to time changes when travelling west to east takes time.
adapternoun 1. a piece of equipment or device which allows a change or modification □ a ‘T’ piece adapter a device for connecting two inputs to one output or vice versa 2. a device that allows two incompatible devices to be connected ADCabbreviation air data computer
addverb 1. to put figures together to form a sum, to make a total o Add the two numbers together to find the sum. 2. to put together to make a larger group or a group with different properties o There are only nine chairs, add another one. A substance is added to the fuel to clean fuel injectors. additionnoun 1. a mathe matical operation consisting in putting numbers together o Addition is normally taught before subtraction, multiplication and division. o The addition sign is +. 2. the act of adding something o With the addition of methanol, the turbine inlet temperature is restored. 3. □ in addition also □ in addition to as well as
additivenoun a chemical substance, often liquid, added to another substance to give it extra qualities o Additives are used in engine oils to prolong the life of the engine. o Anti-icing additives are used in radiator coolants.
ADF abbreviation automatic direction finder
adiabaticadjective 1. referring to processes through which heat cannot be lost or gained 2. referring to a change in temperature in a mass of air, which occurs when the air is compressed or expanded by an increase or decrease in atmospheric pressure and does not involve the air losing heat to, or gaining heat from, its surroundings
adjustverb to change and improve the position or setting of a piece of equipment o The pilot adjusts the throttle or propeller controls. □ to adjust the seat to move the seat into a position suitable for yourself □ to adjust the volume to increase or decrease the volume to improve the sound quality
adjustableadjective designed to be adjusted o An adjustable stop on the throttle control ensures a positive idling speed. adjustmentnoun 1. a change to improve the setting, position or operation of something o A slight adjustment to the seat will make it much more comfortable to sit in. 2. the act of changing something to improve its setting or position o Maximum system pressure is often controlled by adjustment of the main engine-driven pump. admitverb to allow to enter o Cold air can be admitted to the cabin through adjustable louvres or shutters. adoptverb to choose to use
something as standard equipment or to make it standard procedure o A policy of no smoking on all flights has been adopted by many airlines. □ widely adopted now in standard use with many companies, institutions and organisations
ADR abbreviation accident data recorder
ADS abbreviation automatic dependent surveillance
ADT abbreviation approved departure time
advancenoun 1. a change that improves something □ enormous advances in aircraft design great progress or developments in aircraft design 2. □ in advance of ahead of o The Gulf region is three hours in advance of GMT.verb 1. to move forwards, or move something forwards □ the throttle lever is advanced the throttle lever is moved forwards 2. to make something happen at an earlier time □ to advance the ignition to adjust the timing of the ignition so that the spark occurs earlier advancedadjective modern and sophisticated o The A340 is an advanced type of aircraft. ‘…a Seattle-based modification company specializing in advanced winglet designs is developing a lightweight winglet for the Boeing 747 200F’ [Flight International 1—7 May 1996]
advantagenoun a good or beneficial factor o The multi-wheel combination has the advantage of smaller and lighter undercarriage structures. □ to take advantage of to get benefit from a situation □ to take advantage of favourable winds to use tailwinds to increase ground speed and thus save time and money. Opposite disadvantage advantageous adjective better □ the most advantageous the best o The minimum time path is the most advantageous for economy. advect /ad’vekt/ verb to move in a horizontal direction due to convection o Dispersal of hill fog takes place when surface heating lifts the cloud base or drier air is advected. advectionnoun the movement of air in a horizontal direction
advection fognoun fog which forms when warmer moist air moves over a colder surface adventnoun an arrival, especially of something very important o With the advent of satellite navigation systems, pilots of light aircraft have a more accurate means of knowing their position.
adverseadjective 1. bad or poor o Only in extremely adverse conditions should the crew evacuate the aircraft. □ adverse handling characteristics aspects of an aircraft’s handling which are poor 2. acting or going against you
adviseverb 1. to inform, to notify o The flight deck advised the cabin crew that descent would start in 20 minutes. 2. to recommend, to suggest o Because of the bad weather, the instructor advised the trainee pilot not to fly. □ to advise against to recommend or to suggest that something should not be done
AEEC abbreviation airlines electronic engineering committee
aeratornoun a device to put a gas – especially carbon dioxide or air – into a liquid. Opposite de-aerator Aerialadjective 1. happening in the air 2. done by an aircraft in flight noun a device to send or receive radio or TV signals o Ice-covering reduces the effectiveness of aerials. (note: The US English word with this meaning is antenna.)