Align To Angular (Aviation)

Alignverb 1. to position along an axis or line o The nose wheel must be aligned in a fore and aft direction during retraction. 2. to set in a correct position in relation to something else o Aligned white marks on the wheel and tyre indicate that there is no creep.

alignmennoun 1. position in relation to an axis or a line □ to check the alignment of something to make sure it is in the correct position relative to an axis or line □ to maintain alignment with the runway to keep the aircraft on the imaginary extended centre line of the runway 2. correct position in relation to something else □ out of alignment not aligned as it should be

alkalinenoun a substance with a pH value of more than 7 alleviate‘ verb to reduce or lessen the harmful effect of something o Anti-icing additives are available to alleviate the problem of icing. alleviationnoun a reduction or lessening of the harmful effect of something o Deep, regular breathing may provide some alleviation from stress.

allocateverb to provide something particular for a given purpose o Special seats are allocated to mothers with small children. allocationnoun the provision of something particular for a given purpose o At the check-in desk, airline staff are responsible for the allocation of seats to passengers. □ frequency allocation the frequency or range of radio frequencies set aside for a particular use o The frequency allocation for VOR is 1 8-117.975 MHz. allowverb to enable, to permit or to authorise o An engine should be run at low rpm after flight to allow engine components to cool. o Additional fuel is carried to allow for holding en route. o Passengers are not allowed to smoke on some aeroplanes.

allowableadjective permitted or authorised o maximum allowable weight o maximum allowable tyre pressure

allowancenoun 1. consideration for possibilities or changing circumstances □ to make allowances for to take into account o When estimating flight duration, make allowances for taxiing time. 2. something such as money given at regular intervals or for a specific purpose o a travel allowance to cover hotel and restaurant bills. 3. the amount of something that somebody is allowed to have ‘… with many four and six seat aircraft, it is not possible to fill all the seats, use the maximum baggage allowance, fill all the fuel tanks and remain within the approved centre of gravity limits’ [Civil Aviation

Authority, General Aviation Safety Sense Leaflet]

alloynoun a mixture of metals an alloy of aluminium and lithium aloftadjective up in the air

alterverb to change, modify or adjust If there is a risk of collision, alter course to the right. o If the rate of descent is too low, alter the throttle setting accordingly. o The rudder linkage was altered to comply with certification requirements.

alterationnoun 1. a change, modification or adjustment o It was discovered that alterations had been made to the log book. o As a result of the accident, alterations were made to the design of the carburettor heat system. 2. the act of making changes, modifications or adjustments □ heading alteration the act of making of heading corrections

alternate adjective1. every other o A, c, e, and g are alternate letters, as are b, d, f, h, etc. □ alternate days every other day o There are outward flights on alternate days, i.e. on Mondays, Wednesdays and Fridays. 2. US same as alternative an aerodrome of second choice to be used if the aircraft cannot be landed at the aerodrome of first choice because of bad weather, etc. o The point of no return is calculated before departure to cover the chance that both the terminal airfield and its alternate become unavailable during flight. verbto happen in turns □ Captain Smith and Captain Jones alternate as CFI on a daily rot a each captain has one day on duty as CFI followed by a day off, on which the other captain acts as CFI alternating current noun an electric current which reverses its direction at regular intervals o Resistance to alternating current remains almost constant and is independent of frequency.

Abbreviation AC

alternativeadjective referring to another or a second possibility o A turbine bypass, in the form of an alternative exhaust duct is fitted with a valve. □ an alternative means of doing something another or different way of doing something ■ noun another choice or possibility o In some emergency situations the pilot may have no alternative but to force-land the aircraft as soon as possible.

alternatornoun a type of generator designed to produce AC power

altimeternoun a radio instrument for measuring vertical distance or altitude □ altimeter check a routine check to ensure that the altimeter pressure setting is correct □ altimeter display the display of altitude information, which can be given in analogue or digital form. » pointer altitudenoun the vertical distance between an aircraft, or a point or a level, and mean sea-level □ to lose altitude to descend from higher to lower altitude □ cabin altitude the artificial altitude created in the cabin by pressurization

alto-prefix at a moderate or

high altitude

altocumulus noun small white cumulus clouds which form as a layer at moderate altitude, usually meaning fair weather. Compare stratocumulus altostratusnoun a uniform layer cloud at moderate altitude

aluminiumnoun a strong, light metal used in the construction of aircraft (note: The US English is aluminum.)

Comment: In recent years, aluminium has been increasingly replaced by the use of composite materials in the construction of different types of aircraft, from small home-built light aircraft to transport aircraft such as the Airbus A320.

aluminumnoun US same as aluminium

AMA abbreviation approach monitoring aid

amberadjective an orange or yellow colour o An amber light flashes on the instrument panel. (note: Amber is often used to describe the colour of the yellow light in traffic signals.) ambientadjective refer ring to the surrounding atmospheric conditions o Fresh ambient air is routed into the cabin. □ ambient temperature the temperature outside the aircraft ambient pressure noun the pressure outside the aircraft

ambiguitynoun something heard or seen which can be understood in more than one way, thus resulting in possible confusion □ to avoid ambiguity to avoid misunderstanding or confusion o Correct use of R/Tphraseology avoids ambiguity.

ambiguous__ adjective able to be understood in more than one way o It is important that R/T transmissions are not ambiguous.

AMD abbreviation amendment amendverb to change, update, improve or correct something □ he amended the entry in his log book he corrected or changed the entry in his log book

amendmentnoun a change, updating, improvement or correction made, e.g., to a document or procedure o When a terminal aerodrome forecast requires amendment, the amended forecast is indicated by inserting AMD after TAF.

ammeternoun an instrument for measuring amperes in order to give the strength of an electric current o The centre-zero ammeter tells the pilot the status of the aircraft battery. ampabbreviation ampere

amperagenoun the strength of an electric current expressed in amperes o Measuring the amperage of a motor can give a rough estimate of the load on the motor. amperenoun a unit of electric current equal to one volt flowing through an impedance of one ohm o a 13-amp fuse o Current flow is measured in amperes. Abbreviation amp □ ampere hours number of amperes per hour o Battery capacity is rated in ampere hours.

ampleadjective plenty of During the course you will have ample opportunity to demonstrate your skill. □ ample time plenty of time amplification noun the act of increasing the strength of an electrical signal o Amplification of the signal increases the volume.

amplifiernoun an electronic device for increasing the strength of an electrical signal o If the power supply from the amplifier to the gauge fails, the needle slowly falls to zero.

amplifyverb to increase the strength of an electrical signal o An electric current is amplified and then transmitted. (note: amplifies – amplifying – amplified)

amplitudenoun the maximum variation of a vibration or oscillation from the position of equilibrium o to calculate fuel required, multiply the duration of the flight by the consumption of the engine at the required power

AMS abbreviation aeronautical mobile service

AMSL abbreviation above mean sea level

AMSS abbreviation automatic message switching system anabaticadjective referring to a warm flow of air travelling up a hillside or mountainside. Compare katabatic anabatic wind noun a wind current, caused by solar heating of the land, that rises up a south-facing mountainside o South-facing slopes are most suitable for the anabatic wind. Compare katabatic wind analogadjective same as analogue

analogousadjective similar or comparable to o Isobars are analogous to contour lines. analogueadjective 1. rep resenting a quantity or signal that varies continuously by means of a physical apparatus such as a dial and pointer o The electronic centralised aircraft monitor (ECAM) does not have analogue presentation of engine information. 2. □ analogue display (on a clock) a traditional hands and face display on a clock or dial. Compare digital display

analyse, analyze verb to break down into parts and study very closely □ to analyse fuel to separate fuel into its different parts to find out what it consists of □ to analyse a chart to examine a chart in detail

analysisnoun breaking down a substance into its parts in order to study them closely o At a crash .site, samples of materials are removed for analysis. (note: The plural form is analyses.) □ chart analysis careful study of charts

anchornoun a device connected to and dropped from a boat in order to prevent the boat from moving in the water ■ verb to drop an anchor to prevent the boat from moving

anemographnoun an instrument which maintains a continuous recording of wind direction and speed on a graph o The anemograph gives a continuous recording of wind velocity which is displayed on a chart and reveals gusts, squalls and lulls.

anemometer‘ noun an instrument, usually attached to a building, with three or four ‘cups’ which rotate with the wind thus providing wind-speed information o The strength of the wind can be seen by the speed with which the anemometer rotates.

aneroidadjective not containing or using liquid

aneroid capsule noun a thin flexible cylindrical box, usually made of metal, which has most of the air removed from it and which expands and contracts with changes in atmospheric pressure o The aneroid capsule in the barometer is connected to a system of levers which operate a pointer.

aneroid switch noun a switch operated by an aneroid capsule

anglenoun the difference in direction between two lines or surfaces measured in degrees

angle of attack noun the angle formed between the relative airflow and the chord line of the aerofoil

Comment: The angle of attack is related to the flight path of the aircraft, not to the angle the wing makes with the horizontal. If the angle of attack becomes too great, the smooth airflow over the upper surface of the wing will break down. If no corrective action is taken by the pilot, there will be a sudden loss of lift and the aircraft will stall.

angle of incidence noun the angle formed between the chord-line of the main-plane and the horizontal when the aircraft is in the rigging position

angle of inclination noun the angle formed between a sloping path or surface and a reference point or line which is either horizontal or vertical o Between any two meridians there is an angle of inclination one to the other which varies with latitude.

Angularadjective refer ring to or forming an angle o The angular difference between the direction of magnetic north and compass north is called variation.