Control
noun 1. the authority or ability to direct somebody or something 2. □ crowd control the management of the movements of large numbers of people 3. checking or examining ■ verb to direct, to manage or to make a machine, system, procedure, etc., work in the correct way o The purpose of the centrifugal .switch is to control the starting and ignition circuits. (note: The word control in English is used in a different way to similar words in other languages. In English, the verb check is more often used to mean ‘look at and verify’ while control is used in the sense of ‘to make something work in a particular way’: the yoke and rudder pedals are used to control the movement of the aircraft. Note also: controlling – controlled.)
control area
noun the airspace above a particular area on the ground, which is controlled by a particular authority.
Abbreviation CTA
control column
noun the main hand control used by the pilot to control the aircraft in roll and pitch
controlled airspace
noun airspace which is governed by rules and regulations which pilots must comply with. Abbreviation CAS
controller
noun 1. a device which ensures that something operates in the correct way o the propeller speed controller 2. a person who manages systems to ensure the smooth operation of procedures
controls
plural noun manual or automatic devices that are used to control a machine, a system, etc., or to make a machine, a system, etc., work in a correct way □ the pilot at the controls of the aircraft the pilot who is operating the flying controls
control surfaces
plural noun moveable aerofoils, usually on the wings and tail-plane, which can be operated from the cockpit by the pilot, thus changing aircraft attitude control tower
noun a tall building on an airfield from which air-traffic controllers organise incoming and outgoing aircraft by speaking to their pilots by radio control zone
noun a designated ATC area. Abbreviation CTR
convection
noun the process by which hot air rises and cool air descends o Heat is transferred from the Earth’s surface upwards largely by convection.
convective
adjective referring to convection, or something which is affected by the vertical circulation of air □ convective movement movement caused by warm air rising and cool air descending
convective clouds
‘klaudz/ plural noun clouds formed as a result of warm moist air rising and condensing at altitude
convenience
noun 1.personal comfort and benefit o Reading lights are provided for passengers’ convenience. □ at your convenience when it is least troublesome for you 2. ease of understanding o For convenience we will assume that the Earth is round. 3. usefulness, or easiness to use convenient
adjective 1. useful o The circular slide rule has a convenient scale for converting weights and volumes. 2. suitable and unlikely to cause problems o We must arrange a convenient time and place for the meeting.
convention
‘ noun 1. an idea which because of long usage has become normal and accepted o By convention, wind direction is the direction from which the wind blows. 2. a meeting involving large numbers of people and long discussions in order to arrive at an agreed course of action often outlined in a public statement o the Tokyo Convention
conventional
adjective usual or familiar to most people o Every pilot must know the conventional symbols used for depicting the various ground features on charts.
converge
‘ verb to come together at a particular point o Meridians converge towards the poles. □ aircraft on converging courses aircraft on courses which may eventually be too close to each other if no corrective action is taken. Opposite diverge convergence
noun the fact of coming together at a particular point o The inter-tropical convergence zone is the zone in which the trade winds from the two hemispheres approach each other. o There is convergence of meridians of longitude at the north and south poles. Opposite divergence
converse
noun the opposite o The converse of port is starboard. □ warm air rises – the converse is also true in other words, cool air descends conversion
noun 1. a change to a different system or set of rules o The conversion of km into nm is not difficult. 2. □ conversion course flying training which enables and qualifies a pilot to fly a different aircraft type
convert
verb to change to a different system or set of rules o to convert km into nm o How do you convert degrees C into degrees F?
converter
noun a device which alters the form of something o A backup converter converts the alternating current power into direct current.
convertible
‘ adjective possible to change easily, e.g. to fit in with a new system or set of standards o The statute mile, unlike the nautical mile, is not readily convertible into terms of angular measurements. convey
verb to carry or move from one place to another o A large number of tubes convey the cooling medium through the matrix. o Buses are used to convey passengers from the aircraft to the terminal building. □ to convey information to pass information from one person to another, or from one place to another cool
adjective a little cold □ cool weather weather which is not hot, warm nor very cold ■ verb to become or cause to become less hot o The airflow is used to cool the oil. i> air-cooled coolant
noun a substance,usually liquid, used to cool something such as an engine o radiator coolant o The coolant is sprayed into the combustion chamber inlet.
cooler
noun a device for cooling A self-contained system, consisting of an oil tank, pump, filter, cooler, and oil jets, lubricates the auxiliary power unit.
cooling
noun the action of making something cool o the cooling of the oil by the airflow ■ adjective reducing the temperature of something □ cooling medium a substance which reduces the temperature of another substance or material
coordinate
verb 1. to bring together the various parts of a procedure or plan to ensure that the operation works correctly o It is the task of air traffic controllers to coordinate the movement of traffic in and out of a terminal. 2. to make different parts of the body work well together o During a hover, helicopter pilots must be able to coordinate movements of both hands and feet.
coordinated flight
noun flight, especially during turns, in which the horizontal and vertical forces acting on the aircraft are in balance o In coordinated flight, the ball in the turn coordinator will be in the centre.
Comment: The ball in the balance indicator of the turn coordinator shows the pilot if the aircraft is in coordinated flight or if it is slipping or skidding. When the ball moves to the left the pilot should apply left rudder pedal pressure, if the ball moves to the right, the pilot should apply right rudder pedal pressure.
Coordinated Universal Time
noun time used in aviation based on the 24-hour clock format. i GMT coordinates
plural noun values used to locate a point on a graph or a map o The airfield can be seen on the map at coordinates B:12.
coordination
noun 1. the process of bringing together the various parts of a procedure or plan to ensure that it works correctly o A rescue coordination centre is set up to control the emergency. 2. the ability to use different parts of the body together well o A pilot must have good hand/eye coordination.
cope
verb to manage to do something, often with some difficulty o In heavy rainstorms, the windscreen wipers may not be able to cope. o The aircraft structure must be able to cope with increased loads caused by turning movement.
copilot
, co-pilot noun a licensed pilot who is second in command to the captain of an aircraft o The copilot landed the aircraft.
copter
noun same as helicopter (informal)
cord
noun a strong thread, usually of nylon o Tyres are of pure rubber and are either cord-strengthened or reinforced. (note: Cord is used to reinforce tyres.)
core
noun the central part, the heart of something o The primary windings consist of heavy gauge wire mounted on a soft iron core. □ the core of a problem the central, most fundamental part of a problem Coriolis force
noun force which accelerates the movement of a rotating mass perpendicular to its motion and towards the axis of rotation o The Coriolis force explains why wind patterns are clockwise in the northern hemisphere and anti-clockwise in the southern hemisphere.
Comment: The Coriolis force acts at a right angle to wind direction and is directly proportional to wind speed. It is named after G. G. Coriolis, a French engineer who died in 1843.
correct
adjective right correct tyre pressure the pressure at which the tyres should be maintained verb 1. to adjust in order to make right A servo-motor fitted in the elevator trim system will automatically correct for loads. o Calibrated airspeed or rectified airspeed is indicated airspeed corrected for instrumentation and installation error. 2. to mark answers right or wrong, as in an examination o The instructor has corrected the students’ examination papers. correction
noun 1. an adjustment or change made to something to make it correct 2. the use of a mathematical formula for adjusting a known inaccuracy of calculation o In applying this correction the reading is converted to that which would occur at mean sea level. 3. an alteration on, e.g. a test answer, which provides the right answer in place of the wrong answer given o I made several corrections to the text.
corrective
adjective referring to something designed to correct
corrective action
noun action taken to put a situation right o If the pilot realises that the plane is too high on the approach, he or she should take corrective action immediately.
correlate
‘ verb to measure something against something else in order to form a relationship between the two o Power is measured not by the amount of work done, but by units of accomplishment correlated with time.
correlation
noun a measurable and predictable relationship o At a given speed, there is a correlation between time and distance.
correspond
verb 1. to fit with or have a direct relationship with o Movements of the control surfaces correspond to movements of the pilots flying controls. 2. to be similar to o In the interests of passenger comfort, the ideal cabin conditions to maintain would be those corresponding to sea level.
corridor
noun same as air corridor
corrode
verb 1. to destroy by a slow chemical process such as rust o The sulphur and water content of turbine fuels tend to corrode the components of the fuel and combustion systems. 2. to be destroyed by a slow chemical process such a rust Aluminium will not corrode easily.
corrosion
noun the destruction of a material by chemical processes Aluminium has a high resistance to corrosion. i> anti-corrosion
corrosion protection
noun action and/or measures taken to prevent corrosion such as rust
corrosive
‘ adjective causing corrosion o Sulphuric acid is very corrosive.
cosine
noun a trigonometric function defined as the length of the side adjacent to an angle in a right angled triangle divided by the length of the hypotenuse.
Abbreviation cos
counter
verb to act against something so as to remove or reduce its effect o For level flight, lift must counter the force of gravity. o Some people find that swallowing hard counters the effects of changes in pressure.
counter-
‘ prefix against
counterclockwise
adjective, adverb US same as anticlockwise
counter-rotating propellers
plural noun propellers which turn in opposite directions (note: They are also called contra-rotating propellers.)
couple
noun two of some thing □ a couple of minutes two or three minutes ■ verb 1. to connect or to join, often mechanically o The auxiliary power unit is a self-contained unit which normally consists of a small gas turbine engine which is coupled to a gearbox. 2. to combine o Pilot error, coupled with poor weather conditions, resulted in an accident.
coupling
noun a joining or connecting component o When not in use, the coupling is sealed by a dust cap.
course
noun 1. an imaginary line across the surface of the Earth which must be followed in order to arrive at the destination □ to alter course to change direction or to follow a different route 2. a formal period of study o a meteorology course 3. continuing time □ in the course of the briefing during the briefing
course correction
noun same as heading correction
course deviation indicator
noun a needle in an omni-bearing indicator which indicates if an aircraft is on a selected course.
Abbreviation CDI
Cover
verb 1. to include e.g.the complete extent of a period of time or the whole of a particular area o The restriction covers the period from 4th-8th July. □ the area covered by the forecast the area which the forecast deals with 2. to deal with a subject, as in a text o The subject of central warning systems is covered in the systems book. 3. to be completely over something so as to hide what is underneath o The area is covered in snow. ■ noun something which goes over something else completely □ cloud cover the amount of cloud □ snow cover a situation in which there is a layer of snow on top of the earth so that the earth cannot be seen
