Batnoun an object shaped like a table-tennis bat used by a person on the ground to guide an aircraft when it is taxiing or parking
batsmannoun some body who uses a pair of bats to guide an aircraft when it is taxiing or parking battery
noun a chemical device that produces electrical current o This piece of equipment is powered by 2 batteries. i> charger bay
noun 1. a space or area in the structure of an aeroplane where equipment can be located o To avoid damage to the wheel bay, the nose wheel must be aligned in a fore and aft direction during retraction. 2. a part of the coast that curves inwards o the Bay of Bengal bayonet fitting
f noun a means of attaching something to something, in which an object with two side pins is inserted into a L-shaped slot in another object on some light-bulbs o Magnetic chip detectors are of the bayonet type fitting and can be removed and replaced very quickly.
beaconnoun a light or radio signal for navigational purposes o If the aircraft turns towards the beacon, signal strength will increase.
beamnoun 1. a long thick metal bar used as a support o A beam is designed with a breaking load of 12 tons but when a three ton load is applied repeatedly, the beam may fail. 2. a shaft of light or radiation travelling in one direction, as from a car’s headlights o The electron gun produces a stream of fast-moving electrons and focuses them into a narrow beam.
beam sharpeningi ,
‘ noun the process of making a radio or light beam narrower o Any system employing beam sharpening is vulnerable to side lobe generation at the transmitter.
bearverb 1. to carry or to hold o The undercarriage has to bear the weight of the aircraft on the ground. □ rain-bearing cloud a cloud carrying moisture which can fall as rain 2. □ to bear something in mind to keep in mind □ it should be borne in mind it should be remembered □ bearing in mind considering o Bearing in mind that she hadn’t flown for three weeks, the student pilot’s landings were very good. 3. to be able to deal with something without becoming distressed or annoyed o He can’t bear the noise. (note: bearing – bore – borne) □ he can’t bear the heat the heat is too much for him
bearing‘ noun 1. the angle, measured in a clockwise direction, of a distant point, relative to a reference direction o To plot a position line from the non-directional radio beacon, it is first necessary to convert the relative bearing to a true bearing and then calculate the reciprocal. 2. a device containing steel balls or needles which allows free rotation of one component around another
Beaufort scalenoun scale from 1-12 used to refer to the strength of wind o Wind speeds can be estimated by using the Beaufort scale of wind force.
belly flopnoun same as belly landing
belly landing,tendiq/ noun an emergency landing of an aircraft when the wheels have not come down belt
noun 1. a long, relatively narrow area □ high-pressure belt long narrow area of high pressure □ precipitation belt a long narrow area of rain, snow or hail □ rain belt long narrow area where rain falls o The cirrus cloud can be 900 miles ahead of the surface front with a rain belt as wide as 200 miles. 2. a loop of strong material connecting two pulleys or wheels, one driving the other
belt-driven‘ adjective (of a wheel) moved by a belt linked to another wheel which, in turn, is moved by a motor or an engine o Aircraft generators are belt-driven or shaft-driven.
belt-driven generator
noun a generator whose pulley is turned by a belt attached to an engine-driven pulley bend /bend/ noun a curve ■ verb to curve from a straight shape (note: bending – bent) □ to bend downwards to curve down from a horizontal position □ to bend upwards to curve up from a horizontal position o The wings support the weight of the aircraft and they bend upwards in flight.
bending load " "" " noun a load that causes a structure to bend Bernoulli’s principle
‘ noun » lift beware
‘ verb to be careful or to watch out for o Beware of carburettor icing. o Beware of other aircraft in the circuit.
beyondpreposition further away than o The radio horizon extends beyond the visible horizon. □ it is beyond his understanding he cannot understand it at all, it is too difficult for him to understand bi-
‘ prefix 1. two 2. twice biannual
adjective happening two times a year □ biannual inspection an inspection done twice every year
bill ,noun US same as note noun 4 bimetallic
adjective made of two metals bimetallic strip
noun a strip made of two separate metals with different rates of expansion, joined together side by side so that when the strip is heated, it bends and makes, or breaks, electrical contact o Circuit breakers use a bimetallic strip as the sensing element.
binaryadjective referring to a number system used in computers that only uses the digits 0 and 1 o Logic gates work with binary data.Computers only process binary information.
biplane, bi-plane noun an old aeroplane design with two pairs of wings, one above the other o Most of the aircraft used in the 1914—18 war were biplanes.
bird strike ,noun a collision between a bird or birds and an aircraft that is flying
black boxnoun same as flight data recorder (note: It is often called the black box, although it is not black.)
blade .noun a flattened part of a propeller or rotor □ blade tip the end of the blade furthest from the centre of rotation □ turbine blade a flat part in a turbine, which has an aerodynamic effect on the air
blade anglenoun the angle between the blade axis and the axis of rotation o With a variable pitch propeller, the blade angle may be changed in flight.
blade slipnoun a loss of propulsive power from a propeller caused by the difference between geometric and effective pitch blade twist
noun 1. a reduction in propeller blade angle from root to tip 2. the unwanted variation in propeller blade pitch from root to tip caused by aerodynamic loads blank
adjective 1. with nothing written, printed or drawn on it o a blank sheet of paper □ a blank form a form without the details filled in 2. (of a TV, computer or video screen) with nothing appearing on it o When he returned to his computer, the screen was blank.
bleed airnoun compressed air from the engine compressor used for cabin pressurisation or to drive other services o Bleed air from the right engine can power items normally powered by the left engine.
bleed screwnoun a small screw in highest point of a hydraulic system to allow for the removal of air or vapour
blind transmission
noun a transmission from one station to another in a situation where two-way communication cannot be established but where it is believed that the called station is able to receive the transmission
blocknoun a large mass of something ■ verb 1. to prevent something such as a fluid from passing freely through a pipe or channel o At high altitude, any water condensing out of the fuel could freeze and block the filters. 2. to prevent a course of action o The government blocked attempts to prevent the building of the new airport.
blockagenoun 1. a collection of something blocking a pipe, narrow channel, filter, etc. o Ice crystals may form to cause a blockage of the fuel filter. 2. the state of being blocked o The blockage was caused by ice.
blow ,noun 1. an impact o a blow on the head 2. a disappointment o The news of her failure in the examination was a severe blow. ■ verb 1. (of the wind or air) to move o The sea breeze may blow almost parallel to the coast. 2. (of a fuse) to break, as it should, when the circuit is overloaded (note: blowing -blew – blown)
blow-backnoun a sudden movement of fluid in the opposite direction to the general flow o A sudden release of pressure may cause a blow-back.
blowernoun a device for blowing air o Air for combustion is obtained from a blower.
boardnoun 1. a flat, square or rectangular piece of wood or other material 2. □ on board on an aircraft o The flight plan records the callsign and the number of people on board. ■ verb to get on to an aircraft o In an emergency many passengers only remember the entrance by which they boarded the aircraft.
boarding gatenoun the door through which passengers leave the terminal building to get on to an aircraft o Boarding gates 1 — 10 are on the left.
boarding passnoun a temporary pass, issued at the check-in desk, which allows the holder to board the aircraft o Boarding passes must be shown at the gate. (note: The plural form Is boarding passes.)
boarding steps‘ plural noun stairs used by passengers and crew to get on board an aircraft o Passengers had to wait in the aircraft for 15 minutes before the boarding steps were put in position.
boarding timenoun the time when passengers are due to board the aircraft o Boarding time is at 13.30 hrs.
bodynoun 1. the whole of a person or an animal 2. the main part of a person, but not the arms or legs 3. the main part of an aeroplane, system, text, etc. o The body of an aircraft is also called the ‘airframe ‘. o A flow-control valve consists of a body and a floating valve. 4. a large mass of liquid or gas □ body of air a large quantity of air behaving in a particular way 5. an object o Acceleration is the rate of change of velocity of a body.
boilverb to heat a liquid until it reaches a temperature at which it changes into gas o Water boils at 100°C. □ boiling point the temperature at which a liquid changes into gas o The boiling point of water is 100°C.
boltnoun 1. a metal rod with a head, which screws into a nut o The two halves of the wheel are held together by bolts. 2. □ bolt of lightning one electrical discharge of lightning verb to attach with a bolt o Aircraft wheels are constructed in two halves which are bolted together.
bondnoun the power that holds surfaces together, when they are joined using heat, cold, chemicals or glue o The de-icing boot breaks the bond between the ice and the outer skin. verb to join surfaces together normally using heat, cold, chemicals or glue o The skin is bonded to the internal members by the redux process.
boomnoun in some aircraft, a spar that connects the tail to the fuselage
boostnoun an increase or improvement The improvement in a country’s economy often gives a boost to the airline industry. verb 1. to make or to help something increase o An oil pump boosts engine oil pressure. 2. to increase o The instructor’s comments boosted the student pilot’s confidence.
boosternoun a device which increases the force or amount of something
booster pumpnoun a centrifugal pump often positioned at the lowest point of a liquid fuel tank to ensure positive pressure in the supply lines to the engine o Fuel is fed through a filter and a booster pump. o The purpose of the booster pump is to prevent fuel aeration.
bootnoun one of a set of flat, flexible tubes bonded to the leading edge or wings and other surfaces which, when pressurised with fluid, break up ice o The boots on the leading edge of the wings were damaged by hail.
bottlenecknoun a buildup of air traffic causing delays in taking off or landing bound
adjective □ bound for on the way to o an aircraft bound for Paris □ the Copenhagen-bound flight the flight on the way to Copenhagen □ outward bound leaving home, especially for another country boundary
noun a physical or imaginary limit between two areas o The boundary between two air masses is called the frontal surface.
boundary layer noun the layer of fluid next to the surface over which it is flowing and, because of friction, travelling more slowly than layers further from the surface
bowsernoun a mobile fuel tank for refuelling aircraft o It is important to prevent the possibility of an electric spark by earthing the aircraft and the bowser.
Boyle’s Lawnoun a scientific principle that states that the volume of a given mass of gas, whose temperature is maintained constant, is inversely proportional to the gas pressure
brace ,‘ verb 1. to strengthen a construction using cross-members and/or wires o Early aircraft were of the braced type of construction. 2. to take a protective body position in preparation for a crash landing o The cabin-crew will repeat the ‘brace ‘ order and brace themselves. □ to brace yourself to quickly prepare yourself mentally and physically for what is shortly to happen
brace position noun the position that a person is recommended to adopt before impact in a crash, protecting the head with the arms and bringing the legs up underneath the chest
bracketnoun 1. a metal support, often triangular or L-shaped □ component bracket a metal device to attach and support a component 2. a range of frequencies within a band of radio frequencies o Terminal VOR is in the frequency bracket 108—112 MHz. 3. round brackets the printing symbol ( ) used to separate words in a sentence, or within a text □ square brackets the printing symbol [ ] used to enclose some types of text
brakenoun a device for stop ping a vehicle or a machine □ parking brake a brake used to prevent the aircraft moving after it has come to a stop verb to slow down or to stop by pressing the brakes o He had to brake hard after landing in order to turn off at the correct taxiway. (note: braking -braked)
brake drumnoun a round hollow part of the brake mechanism, which is attached to the wheel and against which the brake shoes rub, thus preventing the wheel from turning braking
noun the act of putting on the brakes to slow down or to stop adjective slowing down o the braking effect of drag i> action breaking load
noun a load capable of being supported before a structure breaks breather
noun 1. a pipe connecting the crankshaft to the atmosphere to prevent build-up of crankcase pressure 2. a short rest (informal) □ to take a breather to have a short break, to relax before starting again breeze
noun a gentle wind especially near the coast o There’s no wind, not even a breeze. □ land breeze a light wind which blows from the land towards the sea o Land and sea breezes occur in coastal areas. □ sea breeze a gentle wind which blows from the sea towards the land The strength of the sea breeze decreases with height.
Briefadjective short □ brief visit a visit that lasts only short time □ brief letter a letter containing only a few words noun general instructions to enable somebody to perform their duties o The inspector’s brief is to find out as much as possible about the causes of accidents.verb to give basic information to somebody o Before takeoff, cabin crew must brief passengers on the location and use of emergency exits and life jackets.