Characternoun 1. a quality or set of qualities which make something different and separate from something else The circulation of the atmosphere is zonal in character. 2. an individual letter, number or symbol used in printing and writing characterisecharacterize verb □ to be characterised by to have qualities or features which make it different and separate from other things o The stratosphere is characterised by a temperature structure which is steady or increases with height.
Characteristicadjective typical of a class or group of things □ a characteristic feature a normal feature of the thing in question noun a feature or quality making something different or separate from something else o Air masses have distinct characteristics which can be used to separate them on a chart. □ handling characteristics features of an aircraft that make it different from other aircraft when handling it □ summer characteristics climatic conditions which are typical of summertime
Chargenoun 1. an amount of electricity o Friction causes a charge of static electricity. o The battery was so old, it would not take a charge. □ a high level of charge a high amount of electricity 2. money demanded or paid for the providing of a service □ overnight parking is free of charge it costs nothing to park overnight verb 1. to pass electrical current through something and thereby make it electrically active o
An installed battery becomes fully charged by the aircraft generator. □ charged particles atmospheric particles which have either a positive or negative electrical charge 2. to take money for a service o We do not charge for overnight parking.
Chartnoun a map for navigational purposes □ significant weather chart a weather chart with important weather information marked on it chase planenoun an aircraft whose role is to escort another aircraft or to photograph it checknoun an examination to make certain that something is as it should be safety check A check was made on the undercarriage and air-frame after the pilot reported a heavy landing. i> run verb to examine something in order to find out if it is correct o It is the pilot’s responsibility to check that the aircraft is airworthy.
‘European Union (EU) airports may be empowered to carry out safety checks on foreign airlines’ [Flight International 17 May 1996]
check-innoun an airline desk where passengers register before a flight o The check-in is on the first floor. □ check-in time time at which passengers should check in check-in countercheck-in desk noun counter where passengers check in checklistnoun a list of
referring to chemistry o a chemical reaction noun a substance used in or
science of chemical substances and their reactions 2. the nature of something o The basic chemistry of fire can be illustrated by the three sides of a triangle representing fuel, oxygen and heat.
chiefadjective most important, main □ the chief factors the most important factors chief flying instructornoun the senior rank of flying instructor. Abbreviation CFI chocknoun a wooden or metal device placed in front of the wheels of a parked aircraft to prevent it from moving o The accident happened because the chocks had been removed before the engine was started.
chokenoun a valve in a carburettor, which controls the amount of air combining with fuel ■ verb 1. to block a tube, etc., making a liquid unable to move □ a choked nozzle a blocked or partly-blocked nozzle 2. to stop breathing because you have inhaled water or smoke
chopper(informal) noun same as helicopter ■ verb to transport something or somebody by helicopter, or to travel by helicopter chordnoun the shortest distance between the leading and trailing edges of an airfoil
circlenoun a line forming a round shape, or a round shape formed by objects or people o They stood in a circle on the tarmac. □ great circle direction an imaginary circle on the surface of the Earth which lies in a plane passing through the centre of the Earth
circuitnoun 1. a complete route around which an electrical current can flow 2. the pattern of take-off, climb-out, turn onto crosswind leg, turn onto downwind leg, turn onto base leg, turn onto final approach and landing o When carrying out practice landings at an aerodrome, the pilot should keep a sharp lookout for other aircraft in the circuit.
circuit-breakernoun a small protective device in the circuit which blows or breaks before a dangerous overload of current arises circuitrynoun a system of electrical circuits o In an anti-skid braking system, circuitry is employed which can detect individual wheel deceleration.
circularadjective shaped like a circle o Anodes are circular plates with centre holes. □ semi-circular shaped like a half-circle ■ noun a document distributed to a large number of people o an aeronautical information circular
circular slide rulenoun a calculating device on which all manner of conversions and complex calculations can be made to assist in flight planning circulateverb to move round in such a way as to arrive at the point of departure o Water circulates via the radiator and pump through to the engine block itself. circulationnoun the act of moving round in such a way as to arrive at the point of departure o The general circulation is indicated by the arrows. □ cyclonic circulation the circulation of air which, if viewed from above, is anticlockwise in the northern hemisphere and clockwise in the southern hemisphere
Civil Aviation Publicationnoun a book, etc., published by the Civil Aviation Authority, each publication having its own reference number o The procedure for obtaining a bearing can be found in CAP 413.
comment: CAA (Civil Aviation Authority) publications are referred to as CAPs and each has a reference number for identification: the procedure for obtaining a bearing is described in CAP 413.
cladverb to protect by covering Alloys can be protected from corrosion by cladding the exposed surface with a thin layer of aluminium. clamshell doornoun the hinged part of a thrust reverser o Clamshell doors are hydraulically or pneumatically opened, and direct the exhaust gases forwards to produce reverse thrust.
classificationnoun the act of putting things into groups or classes because they possess particular common features o Classification of aircraft consists of a multilevel diagram with each category divided into sub-categories. A full classification of layer cloud is given in the table.
classifyverb to group items so that those with similar characteristics are in the same group o Precipitation is classified as light, moderate or heavy according to its rate of fall. o The weather associated with visibility reductions by particles suspended in the atmosphere is classified either as fog, mist, haze, or smoke.
clearadjective 1. referring to conditions in which it is easy to see, e.g. with no cloud or fog □ a clear sky a sky with no cloud □ a clear winter night a night with no fog, mist or other conditions which might impair visibility 2. possible to easily see through 3. with nothing blocking the way □ clear runway, the runway is clear nothing is on the runway □ keep the exits clear do not put anything and do not stand in front of the exits 4. away from 5. easy to hear □ clear of cloud either above or below cloud □ keep clear (of) keep away (from) 6. easy to understand o The explanation is very clear. 7. understood 8. understood □ is it clear? do you understand? verb 1. to remove a blockage or some other unwanted effect which prevents a system from working correctly o A heater element is fitted to clear the detector of ice. 2. to disappear o In winter frost and fog are slow to clear. 3. to make sure that it is all right to do something □ clear it with the CFI make sure that the CFI agrees with the request 4. to officially ask people to quickly leave a given area or place □ to clear the building to quickly leave the building ‘…the principles of weight and balance should have been learned by all pilots during their initial training, but it is clear that, afterwards, some forget’ [Civil Aviation Authority, General Aviation Safety Sense Leaflet]
Comment: On 27th March 1977 two Boeing 747s collided on the runway at Los Rodeos airport Tenerife in poor visibility, resulting in 575 deaths. A KLM 747 commenced take-off while a Pan Am 747 was still taxiing towards it on the same runway. There was clearly a breakdown in communications, perhaps a misunderstood radio call. The Pan Am aircraft had been asked by the controller, who was unable to see either aircraft due to low cloud, ‘Are you clear of the runway?’ The KLM aircraft had already commenced the take-off roll without clearance. It is possible that the KLM pilot mistook the call to the other aircraft thinking that he was ‘clear to take off’.
clearancenoun 1. a space made to allow for the movement of hardware relative to other hardware o clearance between rocker arm and valve tip 2. official permission o Obtain clearance for IFR flight. 3. the disappearance of something unwanted, often rain, fog or snow o Low temperatures caused a delay in the clearance of fog.
the point to which an aircraft is allowed to proceed when granted an air traffic control clearance
exam result which is in no doubt clear to landnoun air traffic control permission to land climatenoun weather conditions particular to a given area o Mediterranean climate o tropical climate □ temperate climate a type of climate which is neither very hot in summer nor very cold in winter. t> continental climaticadjective refer ring to climate or weather conditions particular to a given area o The aircraft forward speed and altitude as well as climatic conditions will influence the value of thrust.
Comment: The climatic zones are: the two polar regions (Arctic and Antarctic); the boreal zone in the northern hemisphere, south of the Arctic; two temperate zones, one in the northern hemisphere and one in the southern hemisphere; two subtropical zones, including the deserts; and the equatorial zone which has a damp tropical climate.
climatologynoun the science of the study of climate o Although pilots do not need to be experts in climatology, they should have a good understanding of the factors which produce changes in the weather.
climbnoun the act of increasing altitude by use of power o Fine pitch enables full engine speed to be used during take-off and climb. Opposite descent ■ verb to increase altitude by use of power o After take-off, the aircraft climbed to 5,000 ft. Opposite descend
clockwiseadjective,adverb describing a circular movement in the same direction as the hands of a clock o a clockwise direction o The relative bearing indicated is measured clockwise from the nose of the aircraft. Opposite anticlockwise clogverb to prevent movement of fluid through a pipe, etc., because of a build-up of solid matter o Most filters allow unfiltered fluid to pass to the system when the filter becomes clogged.
Comment: The most important types of cloud are the following: altocumulus, cloud formed at about 12,000 feet as a layer of rounded mass with a level base; altostratus, cloud formed as a continuous layer between 6,000 and 20,000 feet usually allowing the sun or moon to be seen from the surface; cirrocumulus, a layer of broken cloud at about 20,000 feet; cirrostratus, layer cloud at about 20,000 feet; cirrus, cloud made of ice crystals at 25,000 – 40,000 feet appearing as hair-like formations; cumulonimbus, cloud formed as a towering mass and often associated with thunderstorms; cumulus, cloud formed in rounded masses with a flat base at low altitude, resulting from up currents of air; nimbostratus, thick dark layer cloud at low altitude from which rain or snow often falls (nimbus = rain cloud); stratocirrus, cloud similar to cirrostratus but more compact; stratocumulus, a layer of connected small clouds at low altitude.