Authorisedauthorized adjective officially allowed, permitted o Aircraft with a maximum authorised weight of 12,500 lb or less. □ an authorized person a person who has been given power to act and perform particular tasks or duties authoritativeadjective in the manner of somebody with authority, in a commanding way □ crew must act in an authoritative manner crew must give firm instructions or orders
authoritynoun 1. complete control or power over something o While boarding, the captain has the authority to ask an unruly passenger to leave the aircraft. 2. an official or government body with the power to make decisions
done without needing to think o In the early stages of training, student pilots have to think about the use of the flying controls, but after a while these actions become automatic. 2. which works by itself without the need of an operator The normal activation method is automatic.
automatic dependent surveillance an electronic surveillance system that uses data that aircraft provide automatically via a datalink and is able to identify and track the aircraft automatic direction finder
automatic pilot noun full form of autopilot Automatic Terminal Information Service noun a recording of information played continuously on a specified radio frequency which gives pilots the current weather, runway in use, etc. o Students listen to the ATIS to practise their language skills.
automationnoun the automatic operation or automatic control of a piece of equipment, a process, or a system o Automation has speeded up baggage handling. o Automation of throttle control has removed the need for pilots to monitor airspeed so closely. o It is possible that the alternate source might provide a reduced level of automation.
autopilot‘ noun a system which automatically stabilises an aircraft about its three axes, restores the original flight path following an upset and, in some systems, causes the aircraft to follow a preselected airspeed, altitude or heading. Full form automatic pilot.
Abbreviation A/P auxiliaryadjective secondary, which is used when necessary to help or substitute for something else auxiliary gearbox noun a gear box which allows main engine power to be used for secondary systems
noun the tail rotor of a helicopter availabilitynoun the fact of being available o The status of an airport is determined by the availability of suitable navigation aids. availableadjective ready for immediate use o On a multi-engine aircraft, all the fuel must be available for use by any engine. averageadjective refer ring to an average o For load sheet purposes, an average weight of the passengers and crew members may be used. ■ noun the total divided by the number of items added o The average of 1, 5, 9, 10 and 15 is 8 (1+5+9+10+15 = 40 ^ 5 = 8). ■ verb to reach a particular figure as an average o Brake temperatures average around 500°C during normal operations.
Abbreviation AVGAS aviation law‘ noun the laws relating to flying aviation routineweather report noun a weather report issued regularly at intervals of an hour or half an hour describing weather conditions at an airport. Abbreviation METAR aviatornoun a person who flies aircraft
avoidverb 1. to prevent something from happening o She just managed to avoid an accident. 2. to keep away from something o Avoid flying close to any person or vessel. o Cumulonimbus clouds and thunderstorms should be avoided by as great a distance as possible.
axial flow compressor noun a compressor in which the flow of air is along the longitudinal axis of the engine o In spite of the adoption of the axial flow type compressor, some engine retain the centrifugal type.
axisnoun 1. an imaginary line around which a body rotates o The Earth rotates around its own axis. o An aircraft moves around three axes — vertical, longitudinal and lateral. i> pitch, roll, yaw 2. a horizontal or vertical scale on a graph, often referred to as the X axis, the horizontal axis, and the Y axis, the vertical axis o The plot shows the effect of airspeed on lift with airspeed .shown on the horizontal axis and lift on the vertical axis. (note: The plural form Is axes.)
axlenoun a shaft on which a wheel is mounted o Unequal tyre-pressures, where two wheels are mounted on the same axle, will result in one tyre carrying a greater share of the load than the other. (note: The wheel either turns round the axle or is fixed to the axle.)
azimuthnoun the horizontal angle or direction of a compass bearing o Where precision approach radar is installed, the controller can inform the pilot if they depart from either the extended centre-line in azimuth or height or both.
backupadjective, noun a second or third system, instrument or computer disk available to be used if the first one fails o The backup system or the backup failed as well. o Backup generators are driven by the engine.
baggagenoun luggage, cases and bags which you take with you when travelling o One passenger had a huge amount of baggage. o She lost one piece of baggage. (note: The word luggage is also used in British English.) □ baggage hall an area where arriving passengers pick up their baggage □ carry-on baggage small bags of limited size and weight that passengers are allowed to take with them into the cabin of an aircraft
balancenoun 1. a state in which weight, force or importance are evenly distributed o The propelling nozzle size is extremely important and must be designed to obtain the correct balance of pressure, temperature and thrust. 2. the act of staying steady ■ verb 1. to be opposite and equal in weight, force or importance to something else o The pressure exerted by the weight of the atmosphere above the level of the bowl balances a column of mercury in the tube. 2. to stay steady, especially when resting on the centre of gravity ‘…balance refers to the location of the centre of gravity along the longitudinal axis of the aeroplane’ [Civil Aviation Authority, General Aviation Safety Sense Leaflet]
ballnoun in an inclinometer, the round object which indicates if a turn is coordinated □ to step on the ball to correct a skid or a slip by putting pressure on the rudder on the side to which the ball in an inclinometer has moved during a turn. If the ball has moved to the left, the turn can be corrected by putting pressure on the left rudder, and vice versa.
BALPAabbreviation British Air Line Pilots Association bandnoun 1. a narrow strip A jet stream is a narrow band of high-altitude strong winds. 2. a range of numbers or frequencies between two limits within a radio system bandwidthnoun the width of a band of radio frequencies o The sharp setting means the bandwidth is reduced to one kilohertz to minimise noise or interference.
bankverb (of an aircraft) to rotate or roll around its longitudinal axis to a particular angle o Stresses are increased when the aircraft banks, turns or pulls out of a dive. ■ noun (of an aircraft) a rotating or rolling movement around its longitudinal axis to a particular angle o An attitude indicator gives the pilot pitch and bank information. bar‘ noun 1. a long, straight, rigid piece of metal o The part is made from a solid bar of aluminium. 2. (in meteorology) a unit of atmospheric pressure equal to 1,000 millibars. i millibar barographnoun an instrument for measuring and recording atmospheric pressure o The most common type of barograph is that which utilises an aneroid capsule mechanically connected to a pen.
barriernoun 1. something such as a wall that prevents the movement of something else o Elevation of the ground over which the aircraft flies can be a dangerous barrier to flight. 2. something that prevents a person from making progress His medical problems were a barrier to his successful completion of the course.
basenoun the bottom part or lowest part ■ verb to develop or develop something from something else o The operation of the auxiliary power unit is based on the gas turbine engine. o The principle of vapour cycle cooling is based upon the ability of a refrigerant to absorb heat.
Basicadjective referring to the most important but often simplest part of something, from which everything else is derived o This chapter provides a basic understanding from which the study of meteorology can develop. □ basic principle a central or fundamental idea or theory basic area navigation noun a standard of performance for navigation that requires an aircraft to remain within 5 nautical miles of the centreline of its course for 95% of the time basisnoun the central and most important part of something from which everything else is derived o The basis of air navigation is the triangle of velocities. (note: The plural form is bases.)