Coverage To Depressurize deactivate (Aviation)

Coverage„ noun 1. the amount of space or time given to a subject, an event, etc.More complete coverage of the one-in-sixty rule is given in the plotting section of these notes. 2. the area within which a radar unit can detect objects o glidepath coverage o localiser coverage

cowlnoun a covering usually made up of hinged or removable panels □ cowl flap a removable or hinged panel of a cowl o Further cooling can be obtained by the use of controllable cowl flaps which regulate the amount of air flowing across the cylinders.

cowlingnoun a covering usually made up of hinged or removable panels o Access to the engine compartment is normally via hinged cowling panels.

CPL abbreviation Commercial Pilot’s Licence

crabnoun a manoeuvre in which an aircraft is steered slightly into a crosswind to compensate for flying slightly off course ■ verb to steer an aircraft slightly into a crosswind to compensate for flying slightly off course craftnoun 1. a boat, etc., for carrying people or goods on water 2. an aircraft or spacecraft for carrying people or goods in the air or in space o An airship is classified as a lighter-than-air craft.

crankcasenoun the part of the engine that houses the crankshaft and also usually the oil pump o Oil passages in the crankcase allow lubricating oil to pass through.

crankshaftnoun the part of a piston engine connecting the pistons, via the connecting rods, to the flywheel and gearbox o Rpm is the number of revolutions per minute that the engine crankshaft is making. crashnoun an accident that causes damage ■ verb to have an accident or collision that causes damage o The aircraft crashed into the sea.

crash-diveverb to move downwards quickly through the air front first and crash, or cause an aircraft to do this

crash-landverb to

land heavily without using the undercarriage, so that the aircraft is damaged o The aircraft crash-landed short of the runway.

crash-landingnoun an act of landing an aircraft heavily, sometimes without the undercarriage o The crash-landing did not damage the aircraft as much as the pilot expected.

createverb to make, to produce  The velocity and pressure of the exhaust gas create the thrust in the turbojet engine.

creepnoun 1. a process of weakening and slow damage to something o Creep is a particular feature of components which are subjected to operation at high temperatures. 2. a slight movement of a tyre on a wheel caused by landing o Aligned white marks on the wheel and tyre indicate that there is no creep.

crestnoun the top of a mountain or wave o Wind speeds increase with height, the speed of the wind at the crest of a mountain or wave being the greatest.

crewnoun two or more people who have responsibility for flight operations

criteriacriterion

criterionnoun a standard by which you define, decide or judge something (note: The plural form is criteria.) □ the criterion for promotion is seniority senior staff will be promoted first

criticaladjective 1.extremely important, essential o Temperature and oil pressure are critical to any type of system. 2. at which an important change occurs o As the angle of attack is increased, it reaches the critical point when the airflow over the upper surface of the wing begins to break down.

crossverb 1. to get from one side of an area to another □ to cross the Atlantic to go from one side of the Atlantic to the other 2. to go across each other at an angle o Meridians intersect at the poles and cross the equator at right angles.

cross-checknoun verification, making certain ■ verb to verify or make certain o Cross-check doors closed and locked and escape slides armed. (note: This word is often used in brief messages from one crew member to another, as from the pilot to cabin staff, to confirm that an action has been carried out.)

cross-countrynoun a flight during which the student pilot must demonstrate navigation skills o the qualifying cross-country flight for the PPL

cross-pointer indicatornoun a display with crossing horizontal and vertical bars to indicate aircraft position in relation to the glideslope

cross-sectionnoun a view of an object seen as if cut through o The diagram is a cross-section of a turbojet engine.

crosswindnoun a surface wind which blows at an angle to the landing or take-off heading o On some aircraft, crosswind take-offs should be made with full aileron deflection in the direction from which the wind is blowing.

Comment: A crosswind landing is one of the most difficult exercises for a student pilot. The final approach is usually made with the aircraft yawed into wind, while tracking the extended runway centreline. Just before touchdown, the pilot aligns the aircraft with the direction of flight using the rudder pedals. Correct timing for the alignment and accurate airspeed are required to achieve positive contact with the runway surface otherwise the aircraft may depart the runway to one side.

crosswind componentnoun that part of the wind force acting at an angle to the direction of flight crosswind legnoun part of the airfield traffic circuit flown at approximately 90° to the direction of take off and climb out, followed by the downwind leg CRT ,abbreviation cathode ray tube

cruisenoun the main part of the flight between top of climb after take-off and descent for landing ■ verb to fly the main part of the flight between top of climb after take-off and descent for landing o We are cruising at 500 kt. o Cruising speed, cruising power and cruising altitude are selected to give maximum engine efficiency and prolong engine life.

cruising altitudecruising level noun the altitude at which most of a flight is flown en route to a destination, from top of climb to top of descent o Our cruising altitude will be 35,000feet.

cruising power noun engine power used to give required speed from top of climb to top of descent usually giving fuel economy and long engine life o Cruising power is about 2,300 rpm.

cruising speed cruise speed noun the speed selected from top of climb to top of descent, usually giving fuel economy and long engine life o The cruising speed is 110 knots.

cruising weightnoun the weight of an aircraft in flight, consisting of its weight when empty, the weight of its payload, and the weight of the fuel that it has left crushverb to damage by pressure o Excessive load on the beam may crush the core.

crystalnoun a regular geometric shape formed by minerals, or as water freezes

CSDU abbreviation constant speed drive unit

CSU abbreviation constant speed unit CTA abbreviation control area CTOT abbreviation calculated take-off time

CTRabbreviation control zone

cubicadjective measured in volume, by multiplying length, depth and width □ cubic centimetres (cc) the usual unit used to measure the capacity of an internal-combustion engine o The engine has a capacity of 2,000cc. Abbreviation cc □ cubic foot, cubic inch, cubic metre, cubic yard the volume of a cube whose edge measures one foot, inch, metre or yard, respectively

cumuliformadjective which develop vertically o cumuli-form clouds such as cumulonimbus

cumulonimbusnoun a dark, low cumulus -type of cloud associated with thunderstorms o A cumulonimbus has a characteristic anvil shape.

Abbreviation CB

cumulusnoun big,fluffy, white or grey cloud heaped or piled up, which develops at low altitude o Cumulus clouds may develop because

of thermal activity resulting from the warming of the surface. o Grey cumulus often develop into cumulonimbus. i> altocumulus, stratocumulus cumulus cloudnoun clouds which form only in an unstable atmosphere and, as the name suggests, often build vertically for great distances. Also called heap cloud current‘ adjective present,actual, happening at the moment □ current weather conditions present weather conditions □ current position the position now ■ noun 1. an electrical supply o alternating current o direct current 2. flow

curvaturenoun a curved shape □ curvature of the earth the curving of the Earth’s surface due to the spherical form of the Earth customaryadjective normal or usual o It is customary for the senior cabin supervisor to introduce herself to passengers at the start of a flight.

customsnoun an official department of government concerned with movement of people and freight across national borders □ customs aerodrome an aerodrome, usually near a border or coast, with customs facilities

customs dutynoun same as import duty o the duty payable on a carton of cigarettes cyclenoun a series of actions which end at the same point as they begin o With the piston engine, the cycle is intermittent, whereas in the gas turbine, each process is continuous. □ life cycle of the thunderstorm cell the process of formation, development and decay of a thunderstorm

cycliccyclicaladjective referring to or happening in a cycle o Off shore and on-shore wind patterns are cyclic.

cyclonenoun a system of winds rotating inwards to an area of low barometric pressure o These areas of low pressure are called hurricanes in the Atlantic Ocean, cyclones in the Indian Ocean and Bay of Bengal, and typhoons in the China Sea. Also called low, depression

cyclonicadjective referring to air movement, which turns in the same direction as the Earth and which, when seen from above, is anticlockwise in the northern hemisphere and clockwise in the southern hemisphere o In winter the sub-tropical high retreats and gives way to cyclonic pressure patterns which produce cool unsettled conditions with rain at times.

cylindernoun a device shaped like a tube, in which a piston moves o Smaller aircraft have a static hydraulic system similar to a car, with a master cylinder and individual brake cylinders at each wheel. □ cylinder block the casing containing the cylinders in a internal combustion engine □ cylinder head the removable top part of a piston engine cylinder containing plugs, inlet and exhaust connections and valves

cylindricaladjective with the shape of a cylinder o The modern jet engine is basically cylindrical in shape.

D abbreviation danger area DA abbreviation danger area DAAIS abbreviation danger area activity information service DACS abbreviation danger area crossing service

DADC abbreviation digital air data computer

DADS abbreviation digital air data system

DALR abbreviation dry adiabatic lapse rate

damagenoun harm that is caused to something o If the temperature rises it can cause serious damage to the engine. ■ verb to cause harm to something o Small stones around the run-up area may damage propellers.

damage tolerancenoun the ability of a material or structure to withstand or resist damage o The structural efficiency of bonded and machined structure is not achieved at the expense of damage tolerance.

dampenverb 1. to decrease or reduce o An accumulator is fitted to store hydraulic fluid under pressure and dampen pressure fluctuations. 2. to make slightly wet dampernoun a device to decrease or reduce something o A yaw damper is usedfor rudder control. D & D abbreviation distress and diversion cell

danger areanoun airspace of a particular length, width and depth, within which at particular times there may be activities which are dangerous to the flight of the aircraft.

Abbreviation D, DA

danger zonenoun an area where danger exists datanoun 1. information made up of numbers, characters and symbols often stored on a computer in such a way that it can be processed o Airspeed information is supplied from an air data computer. □ meteorological data information about weather conditions stored on a computer 2. information. t> recorder

datumnoun a reference or base point of a scale or measurement, e.g. mean sea level datum shift trim systemnoun a trim system which varies the incidence of an all-moving tailplane without moving the cockpit controls o In some aircraft, the datum shift is operated automatically. dB abbreviation decibel DC abbreviation direct current

DCL abbreviation

departure clearance de-‘ prefix undo, remove or stop o deactivate 

Depressurize deactivateverb to turn off a system or a piece of equipment thus stopping it being ready to operate o On some aircraft nose wheel steering must be deactivated prior to retraction.