Cloud basenoun the bottom part of a layer of cloud o In general, the lower the cloud base, the less heat is lost by the earth.
cloud ceilingnoun the height above the ground or water of the base of the lowest layer of cloud cloud groupnoun a collection of different cloud types which have similarities, e.g. stratus clouds cm abbreviation centimetre co-prefix together □ co-axial having the same axis □ co-located having the same location coalesceverb to join together to form a large mass or number o The moisture in the air coalesces into large water droplets.
coalescencenoun the act of joining together to form a larger mass or number o Coalescence of water vapour in the atmosphere forms larger droplets of water.
coastnoun an area where the land meets the sea Valentia is situated on the coast of south west Ireland. coastaladjective refer ring to the coast □ coastal area an area near a coast o Land and sea breezes occur in coastal areas.
coastal refractionnoun change in direction of waves when a signal crosses a coastline from sea to land
coastlinenoun the out line of a coast seen from a distance or on a map It is normally easy to identify a coastline or island.
coatnoun a thin covering of a substance such as paint o The coats of paint on a large aircraft significantly increase its weight. verb to cover with a thin layer of a substance such as paint o Metals are coated for protection against corrosion.
coatingnoun 1. a thin layer of a substance o There are two coatings on the inside of CRT screens. 2. the act of covering with a thin layer of a substance
cocknoun a manually controlled valve or tap to control the flow of a liquid o It is necessary to have a master cock for each engine.
cockpitnoun the forward area in an aircraft from where the aircraft is controlled by the pilot o In the case of an in-flight oil loss, a warning indicator will light in the cockpit. ‘.. .in the cockpit of the future there will be two animals, a pilot and a dog. The pilot will be there to feed the dog, and the dog will be there to bite the pilot if he tries to touch anything’ [NYT News Service]
codenoun 1. a system of numbers, letters or symbols used to represent language which has to be learned and decoded in order for the receiver to understand the meaning 2. a series of pulses by which an aircraft transponder replies to a signal from the ground codesharenoun □ code-share deal an agreement between airlines regarding connecting flights o The two airlines have entered into a code-share deal for flights between Dubai and Bangkok.
codeshare partnernoun an airline which has an agreement with another airline regarding connecting flights codesharingnoun 1.a procedure which allows travellers to use connecting flights between one airline and another partner airline for worldwide destinations 2. an arrangement by which two airlines sell seats on the same flight using their own flight numbers
coefficientnoun a mathematical quantity placed before and multiplying another C of A abbreviation certificate of airworthiness
C of G abbreviation centre of gravity coilnoun a device consisting of coiled wire for converting low voltage to high voltage o A voltage coil is connected across the generator.
coiled wirenoun a length of wire twisted round and round o A coiled wire connects the terminal to earth.
coincideverb to happen at the same time and/or in the same place o When the aircraft heading is directly into wind or down wind, track and heading coincide.
coincidentadjective happening at the same place or at the same time o The Earth’s true north and magnetic north poles are not coincident.
cold‘ noun an area of slack pressure gradient between two centres of high or low pressure o The persistence and movement of cols are governed by the movement of the adjacent pressure systems.
cold frontnoun an advancing mass of cold air, moving under and lifting warmer air o A cold front brought rainy, windy conditions to the country.
collapsenoun a sudden and complete fall □ the collapse of a company the end of the existence of the company ■ verb 1. to fall suddenly and completely o The magnetic field will reach a maximum in one direction, collapse to zero and reach a maximum in the opposite direction. 2. to fold or to close suddenly and unintentionally □ the undercarriage collapsed (of an apparatus) the undercarriage could not support the aircraft and broke or retracted on its own 3. to faint □ the passenger collapsed the passenger fell and became semi- or fully unconscious because of some medical problem ‘… as the aeroplane slid off the runway, the left landing gear collapsed’ [Pilot]
collectverb 1. to gather over a period of time o Any given object will usually collect ice more quickly at high speed. 2. to take something or to pick something up from a place collectionnoun 1. a number of things brought together o a collection of vintage aircraft 2. an act of being collected by somebody o The documents are in the office awaiting collection.
collideverb to bump or to crash into something o The aircraft left the runway and collided with a fire truck.
collisionnoun a crash between two objects, two vehicles, etc. If there is a risk of collision, alter course to the right. □ collision avoidance the prevention of collisions by taking measures beforehand to ensure that they do not happen
columnnoun 1. a body of fluid or solid with a tall, narrow shape o Torricelli first demonstrated that the atmosphere has weight by showing that it can support a column of liquid. 2. a vertical section of a table in a document o Column four of the table shows the totals of the other three columns.
combatverb to fight against Fire extinguishers are provided to combat fire.
combat aircraftnoun aircraft designed for warfare
combinationnoun two or more things brought together to form one o The combination of wind direction and wind speed is called velocity.
combineverb to bring two or more things together to make one o The stabilising channels for ailerons and elevators are combined. o Thrust and lift combine to overcome drag and gravity.
combustibleadjective burning or igniting easily □ combustible materials materials which will catch fire easily, e.g. wood, paper, etc.
combustionnoun burning, especially that which takes place in an engine o The heat generated by combustion is considerable.
combustion chambernoun the part of the cylinder in a piston engine where the ignition of the fuel/air mixture takes place
combustornoun the part of a jet or gas-turbine engine that burns fuel to produce power. It consists of the fuel injection system, the igniter, and the combustion chamber.
commandnoun an order □ the command to evacuate the order to leave the aircraft in an emergency □ in command having responsibility for and authority over ■ verb to order something to be done o The captain commanded the evacuation of the aircraft.
commandernoun a pilot in control of, and responsible for, the aircraft and its contents during flight time □ the commander of an aircraft the member of the flight crew specified by the operator as being the commander
commenceverb to start to do something □ commence the evacuation start getting people out of the aircraft
commercialadjective referring to a business activity □ commercial aviation flying as a business enterprise
commercial aircraftnoun aircraft used to carry cargo or passengers for payment
Commercial Pilot’s Licensenoun the license that a person requires to be pilot-in-command of public transport aircraft certified for single-pilot operations. Abbreviation CPL
common sensenoun ordinary good sense o You should use your common sense as well as follow the rules if a passenger feels unwell.
commsabbreviation communications
communicateverb to make contact with somebody in order to pass information o The cabin attendants should communicate with the captain.
communicationnoun the act of passing information to somebody usually, but not always, by using language o Two methods of communication are available to crew members — language and hand signals.
communication linknoun a telephone or radio connection, as between the ground crew and flight deck while an aircraft is preparing for departure
communicationsplural noun a system of passing information o satellite communications o VHF communications are allocated the frequency bracket 118— 137MHz. Abbreviation comms
commutatornoun a device containing metal bars connected to the coils of a generator to produce electrical current o As the power output required is DC not AC, a commutator is fixed at one end of the armature.
compactadjective small, close together, or not taking much space o The annular system, as used on modern aircraft, provides a compact system, and, for the same output and mass flow, a shorter system. ■ verb 1. to make smaller or more dense by pressing 2. to compress, by driving over with heavy machinery o When taxiing on grass, aircraft wheels compact the earth as the aircraft moves over it.
compactionnoun the act of pressing things together to form one, or of compressing something to make it hard o The speed of impact when the aircraft passes through a snowstorm causes compaction of snow-flakes into a solid mass on leading edges and air-intakes.
comparableadjective possible to compare equally with something else o Titanium is nonmagnetic and has an electrical resistance comparable to that of stainless steel.
comparatornoun a device to compare two things o The autopilot comparator monitors the operation of the elevator and aileron channels.
compareverb to find the similarities and dissimilarities between two or more things o When the chart is properly orientated, it is easier to compare the distance between landmarks on the ground with their corresponding distances on the chart. o An aneroid barometer is small compared with a mercury barometer. (note: Compare with is regarded by some as better usage than compare to.)
comparisonnoun a statement expressing the differences and similarities between two or more things o A table showing a comparison of fixed points on various temperature scales is given on page three.
compartmentnoun a small space or area in a structure for a particular purpose o engine compartment □ crew compartment the area reserved for crew
compassnoun an instrument usually with a magnetic needle which always points to the magnetic north
compass bearingnoun a direction or position relative to a fixed point measured in degrees on a compass
compatibilitynoun the ability of a component to operate successfully with other components o Problems of compatibility caused the computerised system to malfunction.
compatibleadjective referring to a component or system which can be used with a different component or system without causing any problems o Computer software designed for one particular system may not be compatible with other systems.
Compensateverb 1.to make up for the loss of something o The floor covering may be designed to compensate for temperature, pressurisation and bending loads. o The fall in air temperature increases the air density and so compensates to some extent for the loss of the thrust due to atmospheric pressure. 2. to give money to a person or organisation to make up for a physical or financial loss o The money offered by the company did not compensate for the injuries she received in the accident.